Arrays.asList 使用细节

//108行
public boolean add(E var1) {
        this.add(this.size(), var1);
        return true;
 }
//148行
public void add(int var1, E var2) {
        throw new UnsupportedOperationException();
 }

//下面看下Arrays.asList的具体实现
@SafeVarargs
public static <T> List<T> asList(T... var0) {
  return new Arrays.ArrayList(var0);
}

//Arrays.ArrayList 实现
private static class ArrayList<E> extends AbstractList<E> implements RandomAccess, Serializable {
    private static final long serialVersionUID = -2764017481108945198L;
    private final E[] a;
    //关键
    ArrayList(E[] var1) {
        this.a = (Object[])Objects.requireNonNull(var1);
    }

    public int size() {
        return this.a.length;
    }

    public Object[] toArray() {
        return (Object[])this.a.clone();
    }

    public <T> T[] toArray(T[] var1) {
        int var2 = this.size();
        if (var1.length < var2) {
            return Arrays.copyOf(this.a, var2, var1.getClass());
        } else {
            System.arraycopy(this.a, 0, var1, 0, var2);
            if (var1.length > var2) {
                var1[var2] = null;
            }

            return var1;
        }
    }

    public E get(int var1) {
        return this.a[var1];
    }

    public E set(int var1, E var2) {
        Object var3 = this.a[var1];
        this.a[var1] = var2;
        return var3;
    }

    public int indexOf(Object var1) {
        Object[] var2 = this.a;
        int var3;
        if (var1 == null) {
            for(var3 = 0; var3 < var2.length; ++var3) {
                if (var2[var3] == null) {
                    return var3;
                }
            }
        } else {
            for(var3 = 0; var3 < var2.length; ++var3) {
                if (var1.equals(var2[var3])) {
                    return var3;
                }
            }
        }

        return -1;
    }

    public boolean contains(Object var1) {
        return this.indexOf(var1) != -1;
    }

    public Spliterator<E> spliterator() {
        return Spliterators.spliterator(this.a, 16);
    }

    public void forEach(Consumer<? super E> var1) {
        Objects.requireNonNull(var1);
        Object[] var2 = this.a;
        int var3 = var2.length;

        for(int var4 = 0; var4 < var3; ++var4) {
            Object var5 = var2[var4];
            var1.accept(var5);
        }

    }

    public void replaceAll(UnaryOperator<E> var1) {
        Objects.requireNonNull(var1);
        Object[] var2 = this.a;

        for(int var3 = 0; var3 < var2.length; ++var3) {
            var2[var3] = var1.apply(var2[var3]);
        }

    }

    public void sort(Comparator<? super E> var1) {
        Arrays.sort(this.a, var1);
    }
}
//此处可以发现，改内部类继承了 AbstractList 但是却没有实现其的add,remove等方法。（下面给出AbstractList 的定义）
public abstract class AbstractList<E> extends AbstractCollection<E> implements List<E> {
    protected transient int modCount = 0;

    protected AbstractList() {
    }

    public boolean add(E var1) {
        this.add(this.size(), var1);
        return true;
    }

    public abstract E get(int var1);

    public E set(int var1, E var2) {
        throw new UnsupportedOperationException();
    }

    public void add(int var1, E var2) {
        throw new UnsupportedOperationException();
    }

    public E remove(int var1) {
        throw new UnsupportedOperationException();
    }
    .......
}

private static <E> List<E> transferArrayList(E[] array){
List<E> transferedList = new ArrayList<>();
Arrays.stream(array).forEach(arr -> transferedList.add(arr));
return transferedList;
}