17.并发类容器设计

private ConcurrentHashMap<String, Object> resultMap = new ConcurrentHashMap<String, Object>();
 for (Map.Entry<String, Object> m : resultMap.entrySet()) {
            count += (Long) m.getValue();
 }

package demo6;
import java.util.concurrent.ConcurrentLinkedQueue;
/**高性能队列、无阻塞
 */
public class DemoConcurrentLinkedQueue {
    /**
     * 说明：list与Queue的区别
     *      1.队列先进先出
     *      2.list集合
     */
/*
    使用take()函数，如果队列中没有数据，则线程wait释放CPU，而poll()则不会等待，直接返回null；同样，空间耗尽时offer()函数不会等待，直接返回false，
    而put()则会wait，因此如果你使用while(true)来获得队列元素，千万别用poll()，CPU会100%的.
*/
    public static  void main(String[] args){
        ConcurrentLinkedQueue<String>  mq = new ConcurrentLinkedQueue<String>();
        mq.add("小明");
        mq.add("王老吉");
        mq.add("大宝");
        mq.add("哈士奇");
        System.err.println(mq.poll());//1.取出该元素并删除
        System.err.println(mq.size());
        System.err.println(mq.peek());//1.取出不删除
        System.err.println(mq.size());
    }
}
输出：
小明
3
王老吉
3

BlockingQueue<String> mq2 = new LinkedBlockingQueue<String>(5);//有界、无界
        mq2.add("1+");
        mq2.add("2+");
        mq2.add("3+");
        mq2.add("4+");
        mq2.add("5+");
        for (Iterator iterator = mq2.iterator();iterator.hasNext();){
            String str = (String) iterator.next();
            System.err.println(str);
        }
        List<String> list = new ArrayList<>();
        System.err.println("批量获取："+mq2.drainTo(list,3));
        for (String s:list){
          

BlockingQueue<String> mq1 = new ArrayBlockingQueue<String>(3);
        mq1.add("a");
        mq1.put("b");
        mq1.add("e");

package demo6;
public class Task implements Comparable<Task> {
    private int id;
    private String name;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    @Override
    public int compareTo(Task o) {
        return this.id > o.id ? 1 : (this.id < o.id ? -1 : 0);
    }
    @Override
    public String toString() {
        return "Task{" +
                "id=" + id +
                ", name=‘" + name + ‘\‘‘ +
                ‘}‘;
    }
}

package demo6;
import java.util.concurrent.SynchronousQueue;
public class DemoSynchronousQueue {
    public static void main(String[] args) {
        final SynchronousQueue<String> synchronousQueue = new SynchronousQueue<String>();
        /**
         * 不可直接使用add()方法，必须先有take方法在前调用(处于阻塞状态，等待add的通知激活)，add()方法在后,
         */
        Thread t1 = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    System.err.println(synchronousQueue.take());
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }, "T1");
        t1.start();
        Thread t2 = new Thread(new Runnable() {
            @Override
            public void run() {
                synchronousQueue.add("哈哈哈哈");
            }
        }, "T2");
        t2.start();
    }
}

package demo6;
import java.util.concurrent.Delayed;
import java.util.concurrent.TimeUnit;
public class WangMin implements Delayed {
    private String name;
    private String id;
    /*结束时间*/
    private long endTime;
    public WangMin(String name, String id, long endTime) {
        this.name = name;
        this.id = id;
        this.endTime = endTime;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public long getEndTime() {
        return endTime;
    }
    public void setEndTime(long endTime) {
        this.endTime = endTime;
    }
    private TimeUnit timeUnit = TimeUnit.SECONDS;
    /*用来判断是否时间已经到期*/
    @Override
    public long getDelay(TimeUnit unit) {
        return this.endTime - System.currentTimeMillis();
    }
    /*相互排序比较时间*/
    @Override
    public int compareTo(Delayed o) {
        WangMin wangMin = (WangMin) o;
        return this.getDelay(this.timeUnit) - wangMin.getDelay(this.timeUnit) > 0 ? 1 : 0;
    }
}