HashMap源码2

public class test {
    @SuppressWarnings({ "rawtypes", "unchecked" })
    public static void main(String[] args) {
        HashMap1<Integer,String> hh = new HashMap1<Integer,String>(3);
        
        //链表添加
        hh.put(0, "0");
        hh.put(16, "16");
        hh.put(16, "1616");
        hh.put(32, "32");
        hh.remove(16);//链表删除
        hh.put(0, "00");
        hh.put(48, "48");
        hh.put(64, "64");
        hh.put(80, "80");
        hh.put(96, "96");
        hh.put(112, "112");
        hh.put(128, "128");
        hh.put(144, "144");//0位置转成红黑树
        hh.put(1, "1");//1位置链表添加
        hh.put(16, "16");//0位置红黑树添加
        hh.remove(96);//红黑树中间删除
        hh.remove(64);//红黑树删除根节点
        hh.remove(144);//红黑树删除叶子节点
        
        
        hh.put(2, "2"); 
        hh.put(3, "3"); 
        hh.put(4, "4"); 
        hh.put(5, "5"); 
        hh.put(6, "6"); 
        hh.put(7, "7"); 
        Set s = hh.keySet();//[64, 0, 32, 96, 128, 1, 2, 3, 4, 5, 6, 7, 16, 48, 80, 112, 144]
        Iterator i = s.iterator();
        if(i.hasNext()) System.out.println(i.next());
//        i.remove();
        if(i.hasNext()) System.out.println(i.next());
        
        
        Spliterator v = s.spliterator();
//        v.forEachRemaining(new Consumer() {
//            @Override
//            public void accept(Object t) {
//                System.out.println(t);//全部元素//[64, 0, 32, 96, 128, 1, 2, 3, 4, 5, 6, 7, 16, 48, 80, 112, 144]
//            }
//        });
        Spliterator j = v.trySplit();//数组前面分割一般出去，后面留下
        v.forEachRemaining(new Consumer() {
            @Override
            public void accept(Object t) {
                System.out.println(t);//16 48 80 112 144（有空元素）
            }
        });
        j.forEachRemaining(new Consumer() {
            @Override
            public void accept(Object t) {
                System.out.println(t);//64, 0, 32, 96, 128, 1, 2, 3, 4, 5, 6, 7
            }
        });
        Spliterator j1 = j.trySplit();
        j1.forEachRemaining(new Consumer() {
            @Override
            public void accept(Object t) {
                System.out.println(t);
            }
        });
        j.forEachRemaining(new Consumer() {
            @Override
            public void accept(Object t) {
                System.out.println(t);
            }
        });
        Spliterator kk = v.trySplit();
        kk.forEachRemaining(new Consumer() {
            @Override
            public void accept(Object t) {
                System.out.println(t);
            }
        });
        v.forEachRemaining(new Consumer() {
            @Override
            public void accept(Object t) {
                System.out.println(t);
            }
        });
        
        
        
        HashMap1.tableSizeFor(128);//128:128,127:128,129:256,255:256,257:512
        Set ss = hh.entrySet();
        ss.forEach(new Consumer() {
            @Override
            public void accept(Object t) {
                System.out.println(t);
            }
        });
    }
}

package map;

public class HashMap1<K,V> extends AbstractMap1<K,V> implements Map1<K,V>, Cloneable, Serializable {
    private static final long serialVersionUID = 362498820763181265L;
    static final int DEFAULT_INITIAL_CAPACITY = 1 << 4;//不直接写16，因为快，16也要转换为0 1，
    static final int MAXIMUM_CAPACITY = 1 << 30;//最大容量，要是2的幂次方
    //数组长度超过0.75就扩容。默认初始容量是16，加载因子是0.75。容量是哈希表中桶(Entry数组)的数量，
    //当哈希表中的条目数超出了加载因子与当前容量的乘积时，通过调用 rehash 方法将容量翻倍。
    static final float DEFAULT_LOAD_FACTOR = 0.75f;
    //一个链表超过8个就变为红黑树
    static final int TREEIFY_THRESHOLD = 8;
    //数组
    public transient Node<K,V>[] table;//长度必须为2的幂  
    //大小，链表元素个数。
    transient int size;
    transient int modCount;//用于快速失败。遍历时候不能修改。
    int threshold;//capacity * load factor, 下次扩容的临界值，size>=threshold就会扩容  
    final float loadFactor;//负载因子可以改
    
    static final int UNTREEIFY_THRESHOLD = 6;

    static final int MIN_TREEIFY_CAPACITY = 64;//数组长度小于64先扩容，先不转为红黑树，

    public static final int hash(Object key) {
        int h;//hashCode是native的，返回int。将hashCode的高16位参与运算
        return (key == null) ? 0 : (h = key.hashCode()) ^ (h >>> 16);//>>>左边补0
    }

    //如果x实现了Comparable接口，则返回 x的Class。
    public static Class<?> comparableClassFor(Object x) {
        if (x instanceof Comparable) {//实现了Comparable接口
            Class<?> c; Type[] ts, as; Type t; ParameterizedType p;
            if ((c = x.getClass()) == String.class) //String就返回String
                return c;
            if ((ts = c.getGenericInterfaces()) != null) {//所有的接口，只要有一个接口是Comparable
                for (int i = 0; i < ts.length; ++i) {
                    if (((t = ts[i]) instanceof ParameterizedType) && ((p = (ParameterizedType)t).getRawType() == Comparable.class) &&
                        (as = p.getActualTypeArguments()) != null && as.length == 1 && as[0] == c) // type arg is c
                        return c;
                }
            }
        }
        return null;
    }
    
    //Returns k.compareTo(x) if x matches kc  
    public static int compareComparables(Class<?> kc, Object k, Object x) {
        return (x == null || x.getClass() != kc ? 0 : ((Comparable)k).compareTo(x));
    }
    
    public static final int tableSizeFor(int cap) {
        //128:128,127:128,129:256,255:256,257:512。
        //负数：32位，最高位是1，最后32位全是1，就返回-1。
        //正数：最高位开始全是1：2^n - 1 + 1,就是最近大的2的幂次方
        int n = cap- 1;//如果cap就是2的幂次方，就不要找最近的大了，就是自己。
        System.out.println(Integer.toBinaryString(n));
        n |= n >>> 1;
        System.out.println(Integer.toBinaryString(n));    
        n |= n >>> 2;
        System.out.println(Integer.toBinaryString(n));
        n |= n >>> 4;
        System.out.println(Integer.toBinaryString(n));
        n |= n >>> 8;
        System.out.println(Integer.toBinaryString(n));
        n |= n >>> 16;
        System.out.println(Integer.toBinaryString(n));//32位全部变成1，
        System.out.println(n);
        return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
    }

    transient Set<Map1.Entry<K,V>> entrySet;

    //负载因子小，数组就大，内存占用大，由于数组多那么就会导致链表短，数组查找O(1)链表短那么查找就快，负载因子小数组就小，链表就长，内存小，由于链表长了，查找时间慢。
    //加载因子这里是可以大于1的。
    public HashMap1(int initialCapacity, float loadFactor) {//负载因子可以改
        if (initialCapacity < 0)
            throw new IllegalArgumentException("Illegal initial capacity: " + initialCapacity);
        if (initialCapacity > MAXIMUM_CAPACITY)
            initialCapacity = MAXIMUM_CAPACITY;
        if (loadFactor <= 0 || Float.isNaN(loadFactor))
            throw new IllegalArgumentException("Illegal load factor: " + loadFactor);
        this.loadFactor = loadFactor;
        this.threshold = tableSizeFor(initialCapacity);//临界值，最近大的2的幂次方。此时容量是0。
    }

    public HashMap1(int initialCapacity) {
        this(initialCapacity, DEFAULT_LOAD_FACTOR);
    }

    public HashMap1() {
        this.loadFactor = DEFAULT_LOAD_FACTOR; // all other fields defaulted
    }

    public HashMap1(Map1<? extends K, ? extends V> m) {
        this.loadFactor = DEFAULT_LOAD_FACTOR;
        putMapEntries(m, false);
    }

    public final void putMapEntries(Map1<? extends K, ? extends V> m, boolean evict) {//通过entrySet来put
        int s = m.size();
        if (s > 0) {
            if (table == null) { // pre-size
                float ft = ((float)s / loadFactor) + 1.0F;
                int t = ((ft < (float)MAXIMUM_CAPACITY) ? (int)ft : MAXIMUM_CAPACITY);
                if (t > threshold)
                    threshold = tableSizeFor(t);
            }
            else if (s > threshold)
                resize();
            for (Map1.Entry<? extends K, ? extends V> e : m.entrySet()) {
                K key = e.getKey();
                V value = e.getValue();
                putVal(hash(key), key, value, false, evict);
            }
        }
    }
    
    public int size() {
        return size;
    }

    public boolean isEmpty() {
        return size == 0;
    }

    public V get(Object key) {
        Node<K,V> e;
        return (e = getNode(hash(key), key)) == null ? null : e.value;
    }

    public final Node<K,V> getNode(int hash, Object key) {
        Node<K, V>[] tab;Node<K, V> first/* 链表第一个元素 */, e/* 下一个节点 */;int n/* 长度 */; K k;
        if ((tab = table) != null && (n = tab.length) > 0 && (first = tab[(n - 1) & hash]) != null) {
            if (first.hash == hash && ((k = first.key) == key || (key != null && key.equals(k))))
                return first;//就是第一个元素
            if ((e = first.next) != null) {
                if (first instanceof TreeNode)
                    return ((TreeNode<K,V>)first).getTreeNode(hash, key);
                do {//查找链表
                    if (e.hash == hash && ((k = e.key) == key || (key != null && key.equals(k))))
                        return e;
                } while ((e = e.next) != null);
            }
        }
        return null;
    }

    public boolean containsKey(Object key) {
        return getNode(hash(key), key) != null;
    }

    public V put(K key, V value) {//已经存在就替换
        return putVal(hash(key), key, value, false, true);
    }
  
    public final V putVal(int hash, K key, V value, boolean onlyIfAbsent,boolean evict) {//onlyIfAbsent=true已经存在就不修改旧值。
        Node<K,V>[] tab;//数组table
        Node<K,V> p/*tab[i]的元素*/; 
        int n/*数组长度*/, i/*所在数组的索引*/;
        if ((tab = table) == null || (n = tab.length) == 0)//为空就去初始化。
            n = (tab = resize()).length;//&运算比取模效率高很多，
        if ((p = tab[i = (n - 1) & hash]) == null)//(table.length - 1) & hash(key)是要放的位置，对table.length取余。数组长度要是2的幂次方。
            tab[i] = newNode(hash, key, value, null);//为null直接放
        else {//数组上也就是链表头有元素，
            Node<K,V> e/*找到的元素*/; K k;
            if (p.hash == hash && ((k = p.key) == key || (key != null && key.equals(k))))
                e = p; //就是链表的头结点替换
            else if (p instanceof TreeNode)//红黑树节点是TreeNode，链表节点是Node
                e = ((TreeNode<K,V>)p).putTreeVal(this, tab, hash, key, value);
            else {//不是头结点，向下找，
                for (int binCount = 0; ; ++binCount) {
                    if ((e = p.next) == null) {//链表末尾
                        //节点的hash就是key的hash。
                        p.next = newNode(hash, key, value, null);//放在链表末尾，链表添加节点。
                        if (binCount >= TREEIFY_THRESHOLD - 1)    //7，== null：已经走到了末尾，就计算一直到末尾有多少个元素。已经有8个添加第9个元素时候treeifyBin()
                            treeifyBin(tab, hash);//转成红黑树
                        break;
                    }
                    System.out.println(e.hash);//走到这里e!=null,
                    if (e.hash == hash && ((k = e.key) == key || (key != null && key.equals(k))))//e!=null，看是不是e，找到链表中这个节点e，
                        break;
                    p = e;//查找e下一个
                }
            }
            if (e != null) { //e不等于null，找到的就是e,替换e。
                V oldValue = e.value;
                if (!onlyIfAbsent || oldValue == null)//onlyIfAbsent=false就修改。
                    e.value = value;
                afterNodeAccess(e);
                return oldValue;
            }
        }
        ++modCount;
        if (++size > threshold)//链表节点总数大于阈值就扩容，不是数组非空个数大于阈值。
            resize();//扩容
        afterNodeInsertion(evict);
        return null;
    }

    public final Node<K,V>[] resize() {//初始化和扩容2倍，2个作用，
        Node<K,V>[] oldTab = table;//原来table作为旧的table,
        int oldCap = (oldTab == null) ? 0 : oldTab.length;//旧容量
        int oldThr = threshold;//旧临界值
        int newCap, newThr = 0;//新容量，新临界值
        if (oldCap > 0) {//旧容量大于0
            if (oldCap >= MAXIMUM_CAPACITY) {//旧容量大于1073741824
                threshold = Integer.MAX_VALUE;//旧临界值=2147483647
                return oldTab;//返回旧table
            }    //旧容量乘以2小于最大值，就扩容2倍。临界值也变成2倍。
            else if ((newCap = oldCap << 1) < MAXIMUM_CAPACITY && oldCap >= DEFAULT_INITIAL_CAPACITY)
                newThr = oldThr << 1; //临界值也变成2倍。
        }
        else if (oldThr > 0) // 旧容量小于0，旧临界值大于0，
            newCap = oldThr;//新容量=旧临界值
        else {               // 旧容量小于0，旧临界值小于0，
            newCap = DEFAULT_INITIAL_CAPACITY;//新容量=16
            newThr = (int)(DEFAULT_LOAD_FACTOR * DEFAULT_INITIAL_CAPACITY);//12,size(链表个数)大于12就扩容，不是数组个数大于12.
        }
        if (newThr == 0) {//新临界值=0，
            float ft = (float)newCap * loadFactor;
            newThr = (newCap < MAXIMUM_CAPACITY && ft < (float)MAXIMUM_CAPACITY ? (int)ft : Integer.MAX_VALUE);
        }
        threshold = newThr;
        Node<K,V>[] newTab = (Node<K,V>[])new Node[newCap];
        table = newTab;
        if (oldTab != null) {
            for (int j = 0; j < oldCap; ++j) {
                Node<K,V> e/*每个链表的头元素*/;
                if ((e = oldTab[j]) != null) {
                    oldTab[j] = null;
                    if (e.next == null)//链表就一个元素，直接放，不就覆盖了？所有元素重新计算索引，不会覆盖。
                        //每列元素都是在自己位置或者加8（数组长度从16变成32）的位置，一个链表的元素不会抢占另一个链表元素的位置。
                        newTab[e.hash & (newCap - 1)] = e;
                    else if (e instanceof TreeNode)//红黑树
                        ((TreeNode<K,V>)e).split(this, newTab, j, oldCap);
                    else {//链表，不是红黑树
                        //遍历一个链表时候，这个链表上的所有元素重新计算位置时候，要么在原来索引位置，要么在加8（数组长度从16变成32）的位置。
                        //所以就有2哥链表。
                        Node<K,V> loHead = null, loTail = null; //不动的元素，还在原来位置
                        Node<K,V> hiHead = null, hiTail = null; //加上8的位置的元素 
                        Node<K,V> next;
                        do {//遍历数组某一列的所有元素
                            next = e.next;
                            if ((e.hash & oldCap) == 0) {//不动的元素，还在原来位置
                                //0,1,2,3,4,5,6,7,8*2,8*4,8*8,8*16.......的组合。原始容量是8扩容后是16。对8和16取余不变，所以索引位置不变。
                                if (loTail == null)
                                    loHead = e;//0=00,32=32,64=64,96=96,128=128,16扩容变成32后，32的倍数不变，
                                else
                                    loTail.next = e;
                                loTail = e;
                            }
                            else {//8 + 0,1,2,3,4,5,6,7,8*2,8*4,8*8,8*16.......的组合。取余加上8即可。
                                if (hiTail == null)
                                    hiHead = e;//48=48,80=80,112=112,144=144,16扩容变成32后，16奇数被的放到+16位置，
                                else
                                    hiTail.next = e;
                                hiTail = e;
                            }
                        } while ((e = next) != null);
                        if (loTail != null) {
                            loTail.next = null;
                            newTab[j] = loHead;//直接放到新数组上面去，不就覆盖了？所有元素重新计算索引，不会覆盖。
                        }
                        if (hiTail != null) {
                            hiTail.next = null;
                            newTab[j + oldCap] = hiHead; 
                        }
                    }
                }
            }
        }
        return newTab;
    }

    public final void treeifyBin(Node<K,V>[] tab, int hash) {//hash位置的链表转为红黑树
        int n = tab.length, index; 
        Node<K,V> e;
        /*if (tab == null || n < MIN_TREEIFY_CAPACITY)//数组长度小于64先扩容，先不转为红黑树，
             resize();//注释掉，转为红黑树测试。
        else*/ if ((e = tab[index = (n - 1) & hash]) != null) {//e有9个元素,e是第一个。
            TreeNode<K,V> hd = null, tl = null;
            do {
                TreeNode<K,V> p = replacementTreeNode(e, null);//new TreeNode<>(p.hash, p.key, p.value, null);
                //TreeNode有parent，left，right，prev，before, after，hash，key，value，next;
                if (tl == null)
                    hd = p;
                else {
                    p.prev = tl;
                    tl.next = p;
                }
                tl = p;
            } while ((e = e.next) != null);
            if ((tab[index] = hd) != null)
                hd.treeify(tab);//从头开始，把这个链表变成红黑树。hd可能不再是tab[index]，因为红黑树顶点会变成一个新的，不一定是hd。
        }
    }

    public void putAll(Map1<? extends K, ? extends V> m) {
        putMapEntries(m, true);
    }

    public V remove(Object key) {
        Node<K,V> e;
        return (e = removeNode(hash(key), key, null, false, true)) == null ? null : e.value;
    }

    public final Node<K,V> removeNode(int hash, Object key, Object value,boolean matchValue, boolean movable) {
        Node<K,V>[] tab; 
        Node<K,V> p/*数组的链表头元素*/; 
        int n/*数组长度*/, index/*查找的索引*/;
        if ((tab = table) != null && (n = tab.length) > 0 &&(p = tab[index = (n - 1) & hash]) != null) {
            Node<K,V> node = null/*找到的元素*/, e/*链表下一个元素*/; 
            K k; V v;
            if (p.hash == hash && ((k = p.key) == key || (key != null && key.equals(k))))
                node = p;//找到的就是头元素
            else if ((e = p.next) != null) {//头元素下一个元素
                if (p instanceof TreeNode)//头结点是红黑树
                    node = ((TreeNode<K,V>)p).getTreeNode(hash, key);//红黑树查找，从头结点开始查找，
                else {//头结点不是红黑树
                    do {
                        if (e.hash == hash && ((k = e.key) == key || (key != null && key.equals(k)))) {
                            node = e;
                            break;
                        }
                        p = e;
                    } while ((e = e.next) != null);
                }
            }
            if (node != null && (!matchValue || (v = node.value) == value || (value != null && value.equals(v)))) {//matchValue=false就根据key删除不根据value
                if (node instanceof TreeNode)//头结点是红黑树
                    ((TreeNode<K,V>)node).removeTreeNode(this, tab, movable);//红黑树删除
                else if (node == p)//第一个元素直接替换
                    tab[index] = node.next;
                else
                    p.next = node.next;//改变指针
                ++modCount;
                --size;
                afterNodeRemoval(node);
                return node;
            }
        }
        return null;
    }

    public void clear() {
        Node<K,V>[] tab;
        modCount++;
        if ((tab = table) != null && size > 0) {
            size = 0;
            for (int i = 0; i < tab.length; ++i)
                tab[i] = null;//数组每个第一个元素置位null。
        }
    }

    public boolean containsValue(Object value) {
        Node<K,V>[] tab; V v;
        if ((tab = table) != null && size > 0) {
            for (int i = 0; i < tab.length; ++i) {//先遍历数组
                for (Node<K,V> e = tab[i]; e != null; e = e.next) {//再遍历链表
                    if ((v = e.value) == value || (value != null && value.equals(v)))
                        return true;
                }
            }
        }
        return false;
    }

    @Override
    public V getOrDefault(Object key, V defaultValue) {
        Node<K,V> e;
        return (e = getNode(hash(key), key)) == null ? defaultValue : e.value;
    }

    @Override
    public V putIfAbsent(K key, V value) {
        return putVal(hash(key), key, value, true, true);
    }

    @Override
    public boolean remove(Object key, Object value) {
        return removeNode(hash(key), key, value, true, true) != null;
    }

    @Override
    public boolean replace(K key, V oldValue, V newValue) {
        Node<K,V> e; V v;
        if ((e = getNode(hash(key), key)) != null &&
            ((v = e.value) == oldValue || (v != null && v.equals(oldValue)))) {
            e.value = newValue;
            afterNodeAccess(e);
            return true;
        }
        return false;
    }

    @Override
    public V replace(K key, V value) {
        Node<K,V> e;
        if ((e = getNode(hash(key), key)) != null) {
            V oldValue = e.value;
            e.value = value;
            afterNodeAccess(e);
            return oldValue;
        }
        return null;
    }

    @Override
    public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
        if (mappingFunction == null)
            throw new NullPointerException();
        int hash = hash(key);
        Node<K,V>[] tab; 
        Node<K,V> first/*第一个元素*/; 
        int n, i;
        int binCount = 0;
        TreeNode<K,V> t = null;
        Node<K,V> old = null;
        if (size > threshold || (tab = table) == null || (n = tab.length) == 0)
            n = (tab = resize()).length;//扩容或者初始化
        if ((first = tab[i = (n - 1) & hash]) != null) {
            if (first instanceof TreeNode)
                old = (t = (TreeNode<K,V>)first).getTreeNode(hash, key);
            else {
                Node<K,V> e = first; //找到的元素
                K k;
                do {
                    if (e.hash == hash && ((k = e.key) == key || (key != null && key.equals(k)))) {
                        old = e;//找到元素
                        break;
                    }
                    ++binCount;
                } while ((e = e.next) != null);
            }
            V oldValue;
            if (old != null && (oldValue = old.value) != null) {
                afterNodeAccess(old);
                return oldValue;
            }
        }
        V v = mappingFunction.apply(key);
        if (v == null) {
            return null;
        } else if (old != null) {
            old.value = v;
            afterNodeAccess(old);
            return v;
        }
        else if (t != null)
            t.putTreeVal(this, tab, hash, key, v);
        else {
            tab[i] = newNode(hash, key, v, first);
            if (binCount >= TREEIFY_THRESHOLD - 1)
                treeifyBin(tab, hash);
        }
        ++modCount;
        ++size;
        afterNodeInsertion(true);
        return v;
    }

    public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
        if (remappingFunction == null)
            throw new NullPointerException();
        Node<K,V> e; V oldValue;
        int hash = hash(key);
        if ((e = getNode(hash, key)) != null && (oldValue = e.value) != null) {
            V v = remappingFunction.apply(key, oldValue);
            if (v != null) {
                e.value = v;
                afterNodeAccess(e);
                return v;
            }
            else
                removeNode(hash, key, null, false, true);
        }
        return null;
    }

    @Override
    public V compute(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
        if (remappingFunction == null)
            throw new NullPointerException();
        int hash = hash(key);
        Node<K,V>[] tab; 
        Node<K,V> first; 
        int n, i;
        int binCount = 0;
        TreeNode<K,V> t = null;
        Node<K,V> old = null;
        if (size > threshold || (tab = table) == null || (n = tab.length) == 0)
            n = (tab = resize()).length;//扩容或者初始化
        if ((first = tab[i = (n - 1) & hash]) != null) {
            if (first instanceof TreeNode)
                old = (t = (TreeNode<K,V>)first).getTreeNode(hash, key);
            else {
                Node<K,V> e = first; K k;
                do {
                    if (e.hash == hash && ((k = e.key) == key || (key != null && key.equals(k)))) {
                        old = e;
                        break;
                    }
                    ++binCount;
                } while ((e = e.next) != null);
            }
        }
        V oldValue = (old == null) ? null : old.value;
        V v = remappingFunction.apply(key, oldValue);
        if (old != null) {
            if (v != null) {
                old.value = v;
                afterNodeAccess(old);
            }
            else
                removeNode(hash, key, null, false, true);
        }
        else if (v != null) {
            if (t != null)
                t.putTreeVal(this, tab, hash, key, v);
            else {
                tab[i] = newNode(hash, key, v, first);
                if (binCount >= TREEIFY_THRESHOLD - 1)
                    treeifyBin(tab, hash);
            }
            ++modCount;
            ++size;
            afterNodeInsertion(true);
        }
        return v;
    }

    @Override
    public V merge(K key, V value,BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
        if (value == null)
            throw new NullPointerException();
        if (remappingFunction == null)
            throw new NullPointerException();
        int hash = hash(key);
        Node<K,V>[] tab; 
        Node<K,V> first; 
        int n, i;
        int binCount = 0;
        TreeNode<K,V> t = null;
        Node<K,V> old = null;
        if (size > threshold || (tab = table) == null || (n = tab.length) == 0)
            n = (tab = resize()).length;
        if ((first = tab[i = (n - 1) & hash]) != null) {
            if (first instanceof TreeNode)
                old = (t = (TreeNode<K,V>)first).getTreeNode(hash, key);
            else {
                Node<K,V> e = first; K k;
                do {
                    if (e.hash == hash && ((k = e.key) == key || (key != null && key.equals(k)))) {
                        old = e;
                        break;
                    }
                    ++binCount;
                } while ((e = e.next) != null);
            }
        }
        if (old != null) {
            V v;
            if (old.value != null)
                v = remappingFunction.apply(old.value, value);
            else
                v = value;
            if (v != null) {
                old.value = v;
                afterNodeAccess(old);
            }
            else
                removeNode(hash, key, null, false, true);
            return v;
        }
        if (value != null) {
            if (t != null)
                t.putTreeVal(this, tab, hash, key, value);
            else {
                tab[i] = newNode(hash, key, value, first);
                if (binCount >= TREEIFY_THRESHOLD - 1)
                    treeifyBin(tab, hash);
            }
            ++modCount;
            ++size;
            afterNodeInsertion(true);
        }
        return value;
    }

    @Override
    public void forEach(BiConsumer<? super K, ? super V> action) {
        Node<K,V>[] tab;
        if (action == null)
            throw new NullPointerException();
        if (size > 0 && (tab = table) != null) {
            int mc = modCount;
            for (int i = 0; i < tab.length; ++i) {
                for (Node<K,V> e = tab[i]; e != null; e = e.next)
                    action.accept(e.key, e.value);//链表也遍历
            }
            if (modCount != mc)
                throw new ConcurrentModificationException();
        }
    }

    @Override
    public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
        Node<K,V>[] tab;
        if (function == null)
            throw new NullPointerException();
        if (size > 0 && (tab = table) != null) {
            int mc = modCount;
            for (int i = 0; i < tab.length; ++i) {
                for (Node<K,V> e = tab[i]; e != null; e = e.next) {
                    e.value = function.apply(e.key, e.value);//链表也遍历
                }
            }
            if (modCount != mc)
                throw new ConcurrentModificationException();
        }
    }

    @Override
    public Object clone() {
        HashMap1<K,V> result;
        try {
            result = (HashMap1<K,V>)super.clone();
        } catch (CloneNotSupportedException e) {
            // this shouldn‘t happen, since we are Cloneable
            throw new InternalError(e);
        }
        result.reinitialize();
        result.putMapEntries(this, false);
        return result;
    }

    final float loadFactor() { return loadFactor; }
    final int capacity() {
        return (table != null) ? table.length : (threshold > 0) ? threshold : DEFAULT_INITIAL_CAPACITY;
    }

    private void writeObject(java.io.ObjectOutputStream s)
        throws IOException {
        int buckets = capacity();
        // Write out the threshold, loadfactor, and any hidden stuff
        s.defaultWriteObject();
        s.writeInt(buckets);
        s.writeInt(size);
        internalWriteEntries(s);
    }
    void internalWriteEntries(java.io.ObjectOutputStream s) throws IOException {
        Node<K,V>[] tab;
        if (size > 0 && (tab = table) != null) {
            for (int i = 0; i < tab.length; ++i) {
                for (Node<K,V> e = tab[i]; e != null; e = e.next) {
                    s.writeObject(e.key);//一个个的写出去
                    s.writeObject(e.value);
                }
            }
        }
    }
    private void readObject(java.io.ObjectInputStream s) throws IOException, ClassNotFoundException {
        // Read in the threshold (ignored), loadfactor, and any hidden stuff
        s.defaultReadObject();
        reinitialize();
        if (loadFactor <= 0 || Float.isNaN(loadFactor))
            throw new InvalidObjectException("Illegal load factor: " + loadFactor);
        s.readInt();                // Read and ignore number of buckets
        int mappings = s.readInt(); // Read number of mappings (size)
        if (mappings < 0)
            throw new InvalidObjectException("Illegal mappings count: " + mappings);
        else if (mappings > 0) { // (if zero, use defaults)
            // Size the table using given load factor only if within
            // range of 0.25...4.0
            float lf = Math.min(Math.max(0.25f, loadFactor), 4.0f);
            float fc = (float)mappings / lf + 1.0f;
            int cap = ((fc < DEFAULT_INITIAL_CAPACITY) ?
                       DEFAULT_INITIAL_CAPACITY :
                       (fc >= MAXIMUM_CAPACITY) ?
                       MAXIMUM_CAPACITY :
                       tableSizeFor((int)fc));
            float ft = (float)cap * lf;
            threshold = ((cap < MAXIMUM_CAPACITY && ft < MAXIMUM_CAPACITY) ?
                         (int)ft : Integer.MAX_VALUE);

            // Check Map.Entry[].class since it‘s the nearest public type to
            // what we‘re actually creating.
            SharedSecrets.getJavaOISAccess().checkArray(s, Map1.Entry[].class, cap);
            Node<K,V>[] tab = (Node<K,V>[])new Node[cap];
            table = tab;

            // Read the keys and values, and put the mappings in the HashMap
            for (int i = 0; i < mappings; i++) {
                K key = (K) s.readObject();
                V value = (V) s.readObject();
                putVal(hash(key), key, value, false, false);
            }
        }
    }

    Node<K,V> newNode(int hash, K key, V value, Node<K,V> next) {
        return new Node<>(hash, key, value, next);
    }

    Node<K,V> replacementNode(Node<K,V> p, Node<K,V> next) {
        return new Node<>(p.hash, p.key, p.value, next);
    }

    TreeNode<K,V> newTreeNode(int hash, K key, V value, Node<K,V> next) {
        return new TreeNode<>(hash, key, value, next);
    }

    TreeNode<K,V> replacementTreeNode(Node<K,V> p, Node<K,V> next) {
        return new TreeNode<>(p.hash, p.key, p.value, next);
    }

    //重新初始化，Called by clone and readObject.
    void reinitialize() {
        table = null;
        entrySet = null;
        keySet = null;
        values = null;
        modCount = 0;
        threshold = 0;
        size = 0;
    }

    // LinkedHashMap使用：后置动作，LinkedHashMap extends HashMap
    void afterNodeAccess(Node<K,V> p) { }
    void afterNodeInsertion(boolean evict) { }
    void afterNodeRemoval(Node<K,V> p) { }
/* ---------Map里面需要输出集合，并且遍历集合，还有分割。--------------------------------------------------- */
    public Set<K> keySet() {
        Set<K> ks = keySet;
        if (ks == null) {
            ks = new KeySet();
            keySet = ks;
        }
        return ks;
    }

    final class KeySet extends AbstractSet<K> {
        public final int size()                 { return size; }
        public final void clear()               { HashMap1.this.clear(); }
        public final Iterator<K> iterator()     { return new KeyIterator(); }
        public final boolean contains(Object o) { return containsKey(o); }
        public final boolean remove(Object key) {
            return removeNode(hash(key), key, null, false, true) != null;
        }
        public final Spliterator<K> spliterator() {
            return new KeySpliterator<>(HashMap1.this, 0, -1, 0, 0);
        }
        public final void forEach(Consumer<? super K> action) {
            Node<K,V>[] tab;
            if (action == null)
                throw new NullPointerException();
            if (size > 0 && (tab = table) != null) {
                int mc = modCount;
                for (int i = 0; i < tab.length; ++i) {
                    for (Node<K,V> e = tab[i]; e != null; e = e.next)
                        action.accept(e.key);
                }
                if (modCount != mc)
                    throw new ConcurrentModificationException();
            }
        }
    }

    public Collection<V> values() {
        Collection<V> vs = values;
        if (vs == null) {
            vs = new Values();
            values = vs;
        }
        return vs;
    }

    final class Values extends AbstractCollection<V> {
        public final int size()                 { return size; }
        public final void clear()               { HashMap1.this.clear(); }
        public final Iterator<V> iterator()     { return new ValueIterator(); }
        public final boolean contains(Object o) { return containsValue(o); }
        public final Spliterator<V> spliterator() {
            return new ValueSpliterator<>(HashMap1.this, 0, -1, 0, 0);
        }
        public final void forEach(Consumer<? super V> action) {
            Node<K,V>[] tab;
            if (action == null)
                throw new NullPointerException();
            if (size > 0 && (tab = table) != null) {//直接使用外部类的属性table
                int mc = modCount;
                for (int i = 0; i < tab.length; ++i) {
                    for (Node<K,V> e = tab[i]; e != null; e = e.next)
                        action.accept(e.value);
                }
                if (modCount != mc)
                    throw new ConcurrentModificationException();
            }
        }
    }

    public Set<Map1.Entry<K,V>> entrySet() {
        Set<Map1.Entry<K,V>> es;
        es = entrySet == null ? (entrySet = new EntrySet())  : entrySet;
        System.out.println(es);
        return es;
    }

    final class EntrySet extends AbstractSet<Map1.Entry<K,V>> {
        public final int size()                 { return size; }
        public final void clear()               { HashMap1.this.clear(); }
        public final Iterator<Map1.Entry<K,V>> iterator() {
            return new EntryIterator();
        }
        public final boolean contains(Object o) {
            if (!(o instanceof Map1.Entry))
                return false;
            Map1.Entry<?,?> e = (Map1.Entry<?,?>) o;
            Object key = e.getKey();
            Node<K,V> candidate = getNode(hash(key), key);
            return candidate != null && candidate.equals(e);
        }
        public final boolean remove(Object o) {
            if (o instanceof Map1.Entry) {
                Map1.Entry<?,?> e = (Map1.Entry<?,?>) o;
                Object key = e.getKey();
                Object value = e.getValue();
                return removeNode(hash(key), key, value, true, true) != null;
            }
            return false;
        }
        public final Spliterator<Map1.Entry<K,V>> spliterator() {
            return new EntrySpliterator<>(HashMap1.this, 0, -1, 0, 0);
        }
        public final void forEach(Consumer<? super Map1.Entry<K,V>> action) {
            Node<K,V>[] tab;
            if (action == null)
                throw new NullPointerException();
            if (size > 0 && (tab = table) != null) {
                int mc = modCount;
                for (int i = 0; i < tab.length; ++i) {
                    for (Node<K,V> e = tab[i]; e != null; e = e.next)
                        action.accept(e);
                }
                if (modCount != mc)
                    throw new ConcurrentModificationException();
            }
        }
    }

    abstract class HashIterator {
        Node<K,V> next;        // next entry to return
        Node<K,V> current;     // current entry
        int expectedModCount;  // for fast-fail
        int index;             // current slot

        HashIterator() {
            expectedModCount = modCount;
            Node<K,V>[] t = table;
            current = next = null;//current是刚刚出去的节点，next是还没有出去的节点。
            index = 0;//遍历时候，所在数组索引。
            if (t != null && size > 0) {  
                do {//初始化时候，next=数组中第一个不为null的元素，也是这个链表的头元素。
                } while (index < t.length && (next = t[index++]) == null);
            }
        }

        public final boolean hasNext() {
            return next != null;
        }

        final Node<K,V> nextNode() {
            Node<K,V>[] t;
            Node<K,V> e = next;
            if (modCount != expectedModCount)//遍历时候不能修改
                throw new ConcurrentModificationException();
            if (e == null)
                throw new NoSuchElementException();
            if ((next = (current = e).next) == null && (t = table) != null) {//链表末尾了
                do {} while (index < t.length && (next = t[index++]) == null);//找下一个数组元素，也就是新的链表头元素。
            }
            return e;
        }

        public final void remove() {//移出去current
            Node<K,V> p = current;
            if (p == null)
                throw new IllegalStateException();
            if (modCount != expectedModCount)
                throw new ConcurrentModificationException();
            current = null;
            K key = p.key;
            removeNode(hash(key), key, null, false, false);//modCount++,就不能遍历了？下面修改expectedModCount为新的modCount。
            expectedModCount = modCount;
        }
    }

    final class KeyIterator extends HashIterator implements Iterator<K> {
        public final K next() { return nextNode().key; }
    }

    final class ValueIterator extends HashIterator implements Iterator<V> {
        public final V next() { return nextNode().value; }
    }

    final class EntryIterator extends HashIterator implements Iterator<Map1.Entry<K,V>> {
        public final Map1.Entry<K,V> next() { return nextNode(); }
    }

    static class HashMapSpliterator<K,V> {
        final HashMap1<K,V> map;
        Node<K,V> current;           
        int index;                  //开始位置
        int fence;                  //结束位置
        int est;                    //大小
        int expectedModCount;        

        HashMapSpliterator(HashMap1<K,V> m, int origin, int fence, int est, int expectedModCount) {
            this.map = m;
            this.index = origin;//开始位置
            this.fence = fence;//结束位置
            this.est = est;//大小
            this.expectedModCount = expectedModCount;
        }

        final int getFence() {  
            int hi;
            if ((hi = fence) < 0) {
                HashMap1<K,V> m = map;
                est = m.size;
                expectedModCount = m.modCount;
                Node<K,V>[] tab = m.table;
                hi = fence = (tab == null) ? 0 : tab.length;
            }
            return hi;
        }

        public final long estimateSize() {
            getFence(); // force init
            return (long) est;
        }
    }

    static final class KeySpliterator<K,V> extends HashMapSpliterator<K,V> implements Spliterator<K> {
        KeySpliterator(HashMap1<K,V> m, int origin, int fence, int est, int expectedModCount) {
            super(m, origin, fence, est, expectedModCount);//new KeySpliterator<>(HashMap1.this, 0, -1, 0, 0);
        }

        public KeySpliterator<K,V> trySplit() {//把数组切割分出去
            int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
            return (lo >= mid || current != null) ? null :
                new KeySpliterator<>(map, lo, index = mid, est >>>= 1, expectedModCount);
        }

        public void forEachRemaining(Consumer<? super K> action) {
            int i, hi, mc;
            if (action == null)
                throw new NullPointerException();
            HashMap1<K,V> m = map;
            Node<K,V>[] tab = m.table;
            if ((hi = fence) < 0) {
                mc = expectedModCount = m.modCount;
                hi = fence = (tab == null) ? 0 : tab.length;
            }
            else
                mc = expectedModCount;
            if (tab != null && tab.length >= hi && (i = index) >= 0 && (i < (index = hi) || current != null)) {
                Node<K,V> p = current;
                current = null;
                do {
                    if (p == null)
                        p = tab[i++];
                    else {
                        action.accept(p.key);
                        p = p.next;
                    }
                } while (p != null || i < hi);//数组链表都要遍历
                if (m.modCount != mc)
                    throw new ConcurrentModificationException();
            }
        }

        public boolean tryAdvance(Consumer<? super K> action) {
            int hi;
            if (action == null)
                throw new NullPointerException();
            Node<K,V>[] tab = map.table;
            if (tab != null && tab.length >= (hi = getFence()) && index >= 0) {
                while (current != null || index < hi) {//数组链表都要遍历
                    if (current == null)
                        current = tab[index++];
                    else {
                        K k = current.key;
                        current = current.next;
                        action.accept(k);
                        if (map.modCount != expectedModCount)
                            throw new ConcurrentModificationException();
                        return true;
                    }
                }
            }
            return false;
        }

        public int characteristics() {
            return (fence < 0 || est == map.size ? Spliterator.SIZED : 0) |
                Spliterator.DISTINCT;
        }
    }

    static final class ValueSpliterator<K,V> extends HashMapSpliterator<K,V> implements Spliterator<V> {
        ValueSpliterator(HashMap1<K,V> m, int origin, int fence, int est, int expectedModCount) {
            super(m, origin, fence, est, expectedModCount);//new ValueSpliterator<>(HashMap1.this, 0, -1, 0, 0);
        }

        public ValueSpliterator<K,V> trySplit() {
            int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
            return (lo >= mid || current != null) ? null :
                new ValueSpliterator<>(map, lo, index = mid, est >>>= 1, expectedModCount);
        }

        public void forEachRemaining(Consumer<? super V> action) {
            int i, hi, mc;
            if (action == null)
                throw new NullPointerException();
            HashMap1<K,V> m = map;
            Node<K,V>[] tab = m.table;
            if ((hi = fence) < 0) {
                mc = expectedModCount = m.modCount;
                hi = fence = (tab == null) ? 0 : tab.length;
            }
            else
                mc = expectedModCount;
            if (tab != null && tab.length >= hi &&
                (i = index) >= 0 && (i < (index = hi) || current != null)) {
                Node<K,V> p = current;
                current = null;
                do {
                    if (p == null)
                        p = tab[i++];
                    else {
                        action.accept(p.value);
                        p = p.next;
                    }
                } while (p != null || i < hi);
                if (m.modCount != mc)
                    throw new ConcurrentModificationException();
            }
        }

        public boolean tryAdvance(Consumer<? super V> action) {
            int hi;
            if (action == null)
                throw new NullPointerException();
            Node<K,V>[] tab = map.table;
            if (tab != null && tab.length >= (hi = getFence()) && index >= 0) {
                while (current != null || index < hi) {
                    if (current == null)
                        current = tab[index++];
                    else {
                        V v = current.value;
                        current = current.next;
                        action.accept(v);
                        if (map.modCount != expectedModCount)
                            throw new ConcurrentModificationException();
                        return true;
                    }
                }
            }
            return false;
        }

        public int characteristics() {
            return (fence < 0 || est == map.size ? Spliterator.SIZED : 0);
        }
    }

    static final class EntrySpliterator<K,V> extends HashMapSpliterator<K,V> implements Spliterator<Map1.Entry<K,V>> {
        EntrySpliterator(HashMap1<K,V> m, int origin, int fence, int est, int expectedModCount) {
            super(m, origin, fence, est, expectedModCount);//new EntrySpliterator<>(HashMap1.this, 0, -1, 0, 0);
        }

        public EntrySpliterator<K,V> trySplit() {
            int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
            return (lo >= mid || current != null) ? null :
                new EntrySpliterator<>(map, lo, index = mid, est >>>= 1, expectedModCount);
        }

        public void forEachRemaining(Consumer<? super Map1.Entry<K,V>> action) {
            int i, hi, mc;
            if (action == null)
                throw new NullPointerException();
            HashMap1<K,V> m = map;
            Node<K,V>[] tab = m.table;
            if ((hi = fence) < 0) {
                mc = expectedModCount = m.modCount;
                hi = fence = (tab == null) ? 0 : tab.length;
            }
            else
                mc = expectedModCount;
            if (tab != null && tab.length >= hi &&
                (i = index) >= 0 && (i < (index = hi) || current != null)) {
                Node<K,V> p = current;
                current = null;
                do {
                    if (p == null)
                        p = tab[i++];
                    else {
                        action.accept(p);
                        p = p.next;
                    }
                } while (p != null || i < hi);
                if (m.modCount != mc)
                    throw new ConcurrentModificationException();
            }
        }

        public boolean tryAdvance(Consumer<? super Map1.Entry<K,V>> action) {
            int hi;
            if (action == null)
                throw new NullPointerException();
            Node<K,V>[] tab = map.table;
            if (tab != null && tab.length >= (hi = getFence()) && index >= 0) {
                while (current != null || index < hi) {
                    if (current == null)
                        current = tab[index++];
                    else {
                        Node<K,V> e = current;
                        current = current.next;
                        action.accept(e);
                        if (map.modCount != expectedModCount)
                            throw new ConcurrentModificationException();
                        return true;
                    }
                }
            }
            return false;
        }

        public int characteristics() {
            return (fence < 0 || est == map.size ? Spliterator.SIZED : 0) | Spliterator.DISTINCT;
        }
    }
/* ---------Map里面需要输出集合，并且遍历集合。--------------------------------------------------- */
    // HashMap1.TreeNode extends LinkedHashMap1.Entry extends HashMap1.Node implements Map.Entry，
    static final class TreeNode<K,V> extends LinkedHashMap1.Entry<K,V> {//红黑树
        TreeNode<K,V> parent;  // red-black tree links，上级节点
        TreeNode<K,V> left;
        TreeNode<K,V> right;
        TreeNode<K,V> prev;    // needed to unlink next upon deletion
        boolean red;
        TreeNode(int hash, K key, V val, Node<K,V> next) {
            super(hash, key, val, next);
        }
//        public final TreeNode<K,V> getParent()        { return parent; }
//        public final TreeNode<K,V> getLeft()        { return left; }
//        public final TreeNode<K,V> getRight()        { return right; }
//        public final TreeNode<K,V> getPrev()        { return prev; }
        
        public String toString() {
            return "key:"+key+",val:"+value+(red==true?"，红":"，黑");
//                    +(next!=null?",next:("+next.toString()+")":"")    //不能造成递归toString()
//                    +(prev!=null?",prev:"+prev.key:"") 
//                    +(parent!=null?",parent:"+parent.key:"")
//                    +(left!=null?",left:("+left.toString()+")":"")
//                    +(right!=null?",right:("+right.toString()+")":"");
        }
        
        //包含这个节点的树的根节点
        final TreeNode<K,V> root() {
            for (TreeNode<K,V> r = this, p;;) {
                if ((p = r.parent) == null)//一直找父节点，就会找到根，
                    return r;
                r = p;
            }
        }

        //红黑树根节点是数组的链表的第一个元素。红黑树和链表特性同时存在。
        static <K,V> void moveRootToFront(Node<K,V>[] tab, TreeNode<K,V> root) {
            int n;
            if (root != null && tab != null && (n = tab.length) > 0) {
                int index = (n - 1) & root.hash;//root节点所在数组的索引
                TreeNode<K,V> first = (TreeNode<K,V>)tab[index];
                if (root != first) {//根节点变换了
                    Node<K,V> rn;
                    tab[index] = root;//红黑树的根设置给数组元素
                    TreeNode<K,V> rp = root.prev;
                    if ((rn = root.next) != null)
                        ((TreeNode<K,V>)rn).prev = rp;
                    if (rp != null)
                        rp.next = rn;//把root从链表的prev和next中移除，
                    if (first != null)
                        first.prev = root;
                    root.next = first;
                    root.prev = null;
                }
                boolean b = checkInvariants(root);
                assert b;
            }
        }

        final TreeNode<K,V> find(int h, Object k, Class<?> kc) {//查找节点
            TreeNode<K,V> p = this;// this为调用此方法的节点
            do {
                int ph, dir; K pk;
                TreeNode<K,V> pl = p.left, pr = p.right, q;
                if ((ph = p.hash) > h)
                    p = pl;
                else if (ph < h)
                    p = pr;
                else if ((pk = p.key) == k || (k != null && k.equals(pk)))
                    return p;
                else if (pl == null)
                    p = pr;
                else if (pr == null)
                    p = pl;
                else if ((kc != null || 
                        // comparableClassFor是如果key实现了Comparable就返回具体类型，否则返回null
                        // compareComparables是比较传入的key和当前遍历元素的key
                        // 只有当前hash值与传入的hash值一致才会走到这里
                        //如果传入的key(k)所属的类实现了Comparable接口,则将传入的key跟p节点的key比较
                        (kc = comparableClassFor(k)) != null) && // 此行不为空代表k实现了Comparable
                        (dir = compareComparables(kc, k, pk)) != 0)//k<pk则dir<0, k>pk则dir>0
                    p = (dir < 0) ? pl : pr;// k < pk则向左遍历(p赋值为p的左节点), 否则向右遍历
                //代码走到此处, 代表key所属类没有实现Comparable, 直接指定向p的右边遍历
                else if ((q = pr.find(h, k, kc)) != null)
                    return q;
                else// 代码走到此处代表上一个向右遍历（pr.find(h, k, kc)）为空, 因此直接向左遍历
                    p = pl;
            } while (p != null);
            return null;
        }

        // 查找节点
        final TreeNode<K,V> getTreeNode(int h, Object k) {
            return ((parent != null) ? root() : this).find(h, k, null);
        }
        // 用于不可比较或者hashCode相同时进行比较的方法
        static int tieBreakOrder(Object a, Object b) {
            int d;//a b类的名字相等
            if (a == null || b == null || (d = a.getClass().getName().compareTo(b.getClass().getName())) == 0)
                d = (System.identityHashCode(a) <= System.identityHashCode(b) ? -1 : 1);
            return d;
        }

        //返回根节点
        final void treeify(Node<K,V>[] tab) {
            TreeNode<K,V> root = null;
            for (TreeNode<K,V> x = this, next; x != null; x = next) {//遍历放每一个节点
                next = (TreeNode<K,V>)x.next;
                x.left = x.right = null;
                if (root == null) {
                    x.parent = null;
                    x.red = false;
                    root = x;
                }
                else {
                    K k = x.key;
                    int h = x.hash;
                    Class<?> kc = null;
                    for (TreeNode<K,V> p = root;;) {//一个节点找位置
                        int dir, ph;
                        K pk = p.key;
                        if ((ph = p.hash) > h)//根节点 > x
                            dir = -1;//左边
                        else if (ph < h)//根节点 < x
                            dir = 1;//右边
                        //相等
                        else if ((kc == null && (kc = comparableClassFor(k)) == null) || (dir = compareComparables(kc, k, pk)) == 0)
                            dir = tieBreakOrder(k, pk);//Hash(k) <= Hash(pk) ? -1 : 1，小于根节点在根的左边，大于根节点在根的右边。

                        TreeNode<K,V> xp = p;
                        if ((p = (dir <= 0) ? p.left : p.right) == null) {//放到左边就看p.left,放到右边就看p.right。不为null就放，为null就继续指向左或者右节点。
                            x.parent = xp;
                            if (dir <= 0)
                                xp.left = x;
                            else
                                xp.right = x;
                            root = balanceInsertion(root, x);//重新调整平衡树，返回新的root。
                            break;//跳出
                        }
                    }
                }
            }//红黑树构造完在moveRootToFront()。红黑树根节点是数组的第一个元素
            moveRootToFront(tab, root);//root节点可能不是原来第一个节点，
        }

        //红黑树太少了变成链表
        final Node<K,V> untreeify(HashMap1<K,V> map) {
            Node<K,V> hd = null, tl = null;//头尾节点
            for (Node<K,V> q = this; q != null; q = q.next) {//this是first节点。红黑树里面的next属性，就是为了以后少了的时候变成红黑树用的。
                Node<K,V> p = map.replacementNode(q, null);//创建new Node()节点，
                if (tl == null)
                    hd = p;
                else
                    tl.next = p;
                tl = p;
            }
            return hd;
        }

        //红黑是添加节点，不是链表添加节点
        final TreeNode<K,V> putTreeVal(HashMap1<K,V> map, Node<K,V>[] tab, int h, K k, V v) {
            Class<?> kc = null;
            boolean searched = false;
            TreeNode<K,V> root = (parent != null) ? root() : this;
            for (TreeNode<K,V> p = root;;) {//找到红黑树根节点
                int dir, ph; K pk;
                if ((ph = p.hash) > h)//h在p左边
                    dir = -1;
                else if (ph < h)//h在p右边
                    dir = 1;
                else if ((pk = p.key) == k || (k != null && k.equals(pk)))//h=p
                    return p;
                // comparableClassFor是如果key实现了Comparable就返回具体类型，否则返回null
                // compareComparables是比较传入的key和当前遍历元素的key
                // 只有当前hash值与传入的hash值一致才会走到这里
                // 如果k所属的类没有实现Comparable接口 或者 k和p节点的key相等
                else if ((kc == null && (kc = comparableClassFor(k)) == null) || (dir = compareComparables(kc, k, pk)) == 0) {
                    if (!searched) {//第一次符合条件, 该方法只有第一次才执行
                        TreeNode<K,V> q, ch;
                        searched = true;
                        // 从p节点的左节点和右节点分别调用find方法进行查找, 如果查找到目标节点则返回
                        if (((ch = p.left) != null && (q = ch.find(h, k, kc)) != null) ||
                            ((ch = p.right) != null && (q = ch.find(h, k, kc)) != null))
                            return q;
                    }// 否则使用定义的一套规则来比较k和p节点的key的大小, 用来决定向左还是向右查找
                    dir = tieBreakOrder(k, pk);// dir<0则代表k<pk，则向p左边查找；反之亦然
                }

                TreeNode<K,V> xp = p;//要放的时候的根节点
                if ((p = (dir <= 0) ? p.left : p.right) == null) {//等于null就放
                    Node<K,V> xpn = xp.next;
                    TreeNode<K,V> x = map.newTreeNode(h, k, v, xpn);
                    if (dir <= 0)
                        xp.left = x;
                    else
                        xp.right = x;
                    xp.next = x;
                    x.parent = x.prev = xp;
                    if (xpn != null)
                        ((TreeNode<K,V>)xpn).prev = x;
                    moveRootToFront(tab, balanceInsertion(root, x));//红黑树根节点是数组链表的第一个元素
                    return null;
                }
            }
        }

        //节点自己调用，删除自己，传进来整个map，整个table。一个链表维护了链表的前驱后继关系（便于后面删除，变少了，再次转换为链表时用），也维护了红黑树的关系。
        final void removeTreeNode(HashMap1<K,V> map, Node<K,V>[] tab, boolean movable) {
            int n;
            if (tab == null || (n = tab.length) == 0)
                return;
            int index = (n - 1) & hash;//hash是这个要删除节点的hash，96
            TreeNode<K,V> first = (TreeNode<K,V>)tab[index], root = first, rl;//first是数组中链表的第一个，root是红黑树的根，
            TreeNode<K,V> succ = (TreeNode<K,V>)next, pred = prev;//96节点自己的prev，next。
            if (pred == null)//根节点在第一个，没有prev，删除的是根节点。考虑空，只有一个元素，2个元素，3个元素。
                tab[index] = first = succ;//链表头指向next，成为链表的第一个，
            else
                pred.next = succ;//链表关系重建
            if (succ != null)//最后一个节点
                succ.prev = pred;
            if (first == null)// tab[index]=null或者就一个元素
                return;
            if (root.parent != null)
                root = root.root();//找根节点
            if (root == null || root.right == null || (rl = root.left) == null || rl.left == null) {
                tab[index] = first.untreeify(map);  // 红黑树转成链表，第一个节点来调用。已经删除节点了。
                return;
            }
            TreeNode<K,V> p = this, pl = left, pr = right, replacement;//this=p是要删除的节点，left，right是左右节点
            if (pl != null && pr != null) {//有左右节点。交换p和后继元素。
                TreeNode<K, V> s/* 后驱 */ = pr/* p的右节点 */, sl/* 查找后驱时候用 */;
                while ((sl = s.left) != null) // 找删除节点p的后驱s
                    s = sl;//一个节点只有左或者右节点，删除之后不会影响平衡性，如果有左右节点删除后会影响平衡性，所以先用后驱替代，后驱只有一个子节点，删除后驱不会影响平衡性。
                boolean c = s.red; s.red = p.red; p.red = c; // p和后驱s交换颜色。
                //交换p和p的后驱。
                TreeNode<K, V> sr = s.right;/* 后驱右节点 */
                TreeNode<K, V> pp = p.parent;/* 删除节点父节点 */
                if (s == pr) { // p的后驱s是p的右节点，p的右节点没有左节点
                    p.parent = s;
                    s.right = p;//先改变p和s的关系
                }
                else {
                    TreeNode<K,V> sp = s.parent;
                    if ((p.parent = sp) != null) {
                        if (s == sp.left)
                            sp.left = p;
                        else
                            sp.right = p;
                    }
                    if ((s.right = pr) != null)
                        pr.parent = s;
                }
                p.left = null;//p的left没有节点
                if ((p.right = sr) != null)
                    sr.parent = p;
                if ((s.left = pl) != null)
                    pl.parent = s;
                if ((s.parent = pp) == null)
                    root = s;
                else if (p == pp.left)
                    pp.left = s;
                else
                    pp.right = s;
                //交换p和p的后驱s完毕，指正交换完毕，
                if (sr != null)//后驱只有右节点，没有左节点，所以用后驱的右节点替代后驱，就是删除后驱。
                    replacement = sr;
                else
                    replacement = p;//此时p在p的后驱的位置
            }
            else if (pl != null)//没有右节点，只有左节点
                replacement = pl;//左节点放到删除位置
            else if (pr != null)//只有右节点，没有左节点
                replacement = pr;//右节点放到删除位置
            else//左右节点都没有
                replacement = p;
            if (replacement != p) {//代替节点！=p，删除p节点，replacement移到p的位置，
                TreeNode<K,V> pp = replacement.parent = p.parent;
                if (pp == null)
                    root = replacement;
                else if (p == pp.left)
                    pp.left = replacement;
                else
                    pp.right = replacement;
                p.left = p.right = p.parent = null;
            }
            //删除是黑节点，黑高变了，从replacement调整红黑树。
            TreeNode<K,V> r = p.red ? root : balanceDeletion(root, replacement);

            if (replacement == p) {  // 删除p
                TreeNode<K,V> pp = p.parent;
                p.parent = null;
                if (pp != null) {
                    if (p == pp.left)
                        pp.left = null;
                    else if (p == pp.right)
                        pp.right = null;
                }
            }
            if (movable)
                moveRootToFront(tab, r);//把根节点移到链表的开头
        }

        //红黑树扩容时候调用((TreeNode<K,V>)e).split(this, newTab, j, oldCap);
        final void split(HashMap1<K,V> map, Node<K,V>[] tab, int index, int bit) {
            TreeNode<K,V> b = this;
            // 2个链表
            TreeNode<K,V> loHead = null, loTail = null;
            TreeNode<K,V> hiHead = null, hiTail = null;
            int lc = 0, hc = 0;
            for (TreeNode<K,V> e = b, next; e != null; e = next) {
                next = (TreeNode<K,V>)e.next;
                e.next = null;
                if ((e.hash & bit) == 0) {//扩容之后还在原来位置的
                    if ((e.prev = loTail) == null)
                        loHead = e;
                    else
                        loTail.next = e;
                    loTail = e;
                    ++lc;
                }
                else {//扩容之后在原来位置 + oldCap的
                    if ((e.prev = hiTail) == null)
                        hiHead = e;
                    else
                        hiTail.next = e;
                    hiTail = e;
                    ++hc;
                }
            }

            if (loHead != null) {
                if (lc <= UNTREEIFY_THRESHOLD)//小于6转成链表
                    tab[index] = loHead.untreeify(map);//红黑树节点太少了变成链表
                else {//大于6转成红黑树
                    tab[index] = loHead;
                    if (hiHead != null) // hiHead==null，说明就一个链表，红黑树没有拆散，直接用这个红黑树就可以。
                        loHead.treeify(tab);//loHead链表转成红黑树
                }
            }
            if (hiHead != null) {
                if (hc <= UNTREEIFY_THRESHOLD)//小于6转成链表
                    tab[index + bit] = hiHead.untreeify(map);
                else {//大于6转成红黑树
                    tab[index + bit] = hiHead;
                    if (loHead != null)//loHead = null，说明就一个链表，红黑树没有拆散，直接用这个红黑树就可以。
                        hiHead.treeify(tab);//hiHead链表转成红黑树
                }
            }
        }
        
        // 左旋转p
        static <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root, TreeNode<K,V> p) {
            TreeNode<K,V> r, pp, rl;
            if (p != null && (r = p.right) != null) {
                if ((rl = p.right = r.left) != null)
                    rl.parent = p;
                if ((pp = r.parent = p.parent) == null)
                    (root = r).red = false;//新的顶点变成新的根节点才修改root为新的顶点p.right，否则root不变还是原来的根。
                else if (pp.left == p)
                    pp.left = r;
                else
                    pp.right = r;
                r.left = p;
                p.parent = r;
            }
            return root;
        }
        
        // 右旋转p
        static <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root, TreeNode<K,V> p) {
            TreeNode<K,V> l, pp, lr;
            if (p != null && (l = p.left) != null) {
                if ((lr = p.left = l.right) != null)
                    lr.parent = p;
                if ((pp = l.parent = p.parent) == null)
                    (root = l).red = false;//新的顶点变成新的根节点才修改root为新的顶点p.left，否则root不变还是原来的根。
                else if (pp.right == p)
                    pp.right = l;
                else
                    pp.left = l;
                l.right = p;
                p.parent = l;
            }
            return root;
        }
        //返回新的root
        static <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root, TreeNode<K,V> x) {
            x.red = true;//插入的是红节点
            for (TreeNode<K, V> xp/* 父 */, xpp/* 爷爷 */, xppl/* 爷爷左 */, xppr/* 爷爷右 */;;) {
                if ((xp = x.parent) == null) {//没有父节点。 插入0
                    x.red = false;//变黑，返回
                    return x;//就是根节点
                }
                else if (!xp.red || (xpp = xp.parent) == null)//父节点黑色，没有爷爷节点
                    return root;//返回新的顶点。  插入32
                if (xp == (xppl = xpp.left)) {//爷爷左边
                    if ((xppr = xpp.right) != null && xppr.red) {//爷爷右节点红色
                        xppr.red = false;
                        xp.red = false;
                        xpp.red = true;
                        x = xpp;//父亲变黑，爷爷右节点变黑，爷爷变红，x指向爷爷继续判断。修改X。root不变，继续判断x。
                    }
                    else {//爷爷右节点黑色
                        if (x == xp.right) {//父亲右边
                            root = rotateLeft(root, x = xp);//左旋父亲 ，返回新的顶点，不是返回根节点。没有break。修改X,XP,XPP。
                            xpp = (xp = x.parent) == null ? null : xp.parent;//root可能变成新的顶点，继续判断父亲。
                        }
                        if (xp != null) {//父亲左边
                            //父亲变黑，爷爷变红，右旋转爷爷
                            xp.red = false;
                            if (xpp != null) {
                                xpp.red = true;
                                root = rotateRight(root, xpp);//返回根节点。root可能变成新的顶点，继续判断x。
                            }
                        }
                    }
                }
                else {//爷爷右边
                    if (xppl != null && xppl.red) {//爷爷左边红色 
                        xppl.red = false;
                        xp.red = false;
                        xpp.red = true;
                        x = xpp;//父亲变黑，爷爷左边变黑，爷爷变红，x指向爷爷继续判断。root不变，继续判断爷爷。  插入64 96 128
                    }
                    else {//爷爷左边黑色
                        if (x == xp.left) {//父亲左边
                            root = rotateRight(root, x = xp);//右旋转父亲。修改X,XP,XPP。root可能变成新的顶点，继续判断父亲。
                            xpp = (xp = x.parent) == null ? null : xp.parent;
                        }
                        if (xp != null) {//父亲右边
                            xp.red = false;
                            if (xpp != null) {
                                xpp.red = true;
                                root = rotateLeft(root, xpp);//父亲变黑，爷爷变红，左旋转爷爷。可能root变成新的顶点，继续判断x。插入48 80 112
                            }
                        }
                    }
                }
            }
        }

        static <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root, TreeNode<K,V> x) {
            for (TreeNode<K,V> xp, xpl, xpr;;)  {
                if (x == null || x == root)
                    return root;
                else if ((xp = x.parent) == null) {
                    x.red = false;
                    return x;
                }
                else if (x.red) {
                    x.red = false;
                    return root;
                }
                else if ((xpl = xp.left) == x) {
                    if ((xpr = xp.right) != null && xpr.red) {
                        xpr.red = false;
                        xp.red = true;
                        root = rotateLeft(root, xp);
                        xpr = (xp = x.parent) == null ? null : xp.right;
                    }
                    if (xpr == null)
                        x = xp;
                    else {
                        TreeNode<K,V> sl = xpr.left, sr = xpr.right;
                        if ((sr == null || !sr.red) && (sl == null || !sl.red)) {
                            xpr.red = true;
                            x = xp;
                        }
                        else {
                            if (sr == null || !sr.red) {
                                if (sl != null)
                                    sl.red = false;
                                xpr.red = true;
                                root = rotateRight(root, xpr);
                                xpr = (xp = x.parent) == null ? null : xp.right;
                            }
                            if (xpr != null) {
                                xpr.red = (xp == null) ? false : xp.red;
                                if ((sr = xpr.right) != null)
                                    sr.red = false;
                            }
                            if (xp != null) {
                                xp.red = false;
                                root = rotateLeft(root, xp);
                            }
                            x = root;
                        }
                    }
                }
                else { // symmetric
                    if (xpl != null && xpl.red) {
                        xpl.red = false;
                        xp.red = true;
                        root = rotateRight(root, xp);
                        xpl = (xp = x.parent) == null ? null : xp.left;
                    }
                    if (xpl == null)
                        x = xp;
                    else {
                        TreeNode<K,V> sl = xpl.left, sr = xpl.right;
                        if ((sl == null || !sl.red) && (sr == null || !sr.red)) {
                            xpl.red = true;
                            x = xp;
                        }
                        else {
                            if (sl == null || !sl.red) {
                                if (sr != null)
                                    sr.red = false;
                                xpl.red = true;
                                root = rotateLeft(root, xpl);
                                xpl = (xp = x.parent) == null ?
                                    null : xp.left;
                            }
                            if (xpl != null) {
                                xpl.red = (xp == null) ? false : xp.red;
                                if ((sl = xpl.left) != null)
                                    sl.red = false;
                            }
                            if (xp != null) {
                                xp.red = false;
                                root = rotateRight(root, xp);
                            }
                            x = root;
                        }
                    }
                }
            }
        }

        //从根开始检查整个树红黑特性，以及prev和next特性。
        static <K,V> boolean checkInvariants(TreeNode<K,V> t) {  
            TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
                tb = t.prev, tn = (TreeNode<K,V>)t.next;
            if (tb != null && tb.next != t)//前面节点的下一个节点 不等于 这个节点
                return false;
            if (tn != null && tn.prev != t)//后面节点的前一个节点不等于这个节点
                return false;
            if (tp != null && t != tp.left && t != tp.right)//parent.left!=这个节点，并且parent.right!=这个节点
                return false;
            if (tl != null && (tl.parent != t || tl.hash > t.hash))
                return false;
            if (tr != null && (tr.parent != t || tr.hash < t.hash))
                return false;
            if (t.red && tl != null && tl.red && tr != null && tr.red)//不能2层红
                return false;
            if (tl != null && !checkInvariants(tl))
                return false;
            if (tr != null && !checkInvariants(tr))
                return false;
            return true;
        }
    }

    // HashMap1.TreeNode extends LinkedHashMap1.Entry extends HashMap1.Node implements Map.Entry，
    static class Node<K,V> implements Map1.Entry<K,V> {
        final int hash;
        final K key;
        V value;
        Node<K,V> next;

        Node(int hash, K key, V value, Node<K,V> next) {
            this.hash = hash;
            this.key = key;
            this.value = value;
            this.next = next;
        }

        public final K getKey()        { return key; }
        public final V getValue()      { return value; }
        public final Node<K,V> getNext()        { return next; }
        public String toString() { return key + "=" + value +","+ ((next != null) ? next.toString() : ""); }

        public final int hashCode() {//native方法
            return Objects.hashCode(key) ^ Objects.hashCode(value);
        }

        public final V setValue(V newValue) {
            V oldValue = value;
            value = newValue;
            return oldValue;
        }

        public final boolean equals(Object o) {
            if (o == this)
                return true;
            if (o instanceof Map1.Entry) {
                Map1.Entry<?,?> e = (Map1.Entry<?,?>)o;
                if (Objects.equals(key, e.getKey()) && Objects.equals(value, e.getValue()))
                    return true;
            }
            return false;
        }
    }
}