ConcurrentHashMap 1.8 MyKey 驗證BRTree

Java 1.7

Yanzhen 

Java 1.8

 

public class MyKey implements Comparable<MyKey>{

	public int key;

	@Override
	public int compareTo(MyKey o) {
		// TODO Auto-generated method stub
		System.out.println("-----------------------------------------" );
		System.out.println("cur key = "+ key + " o.key = "+ o.key   );
		return key - o.key;
	}

	public MyKey(int key) {
		super();
		this.key = key;
	}

	@Override
	public int hashCode() {
//		final int prime = 31;
//		int result = 1;
//		result = prime * result + key;
		//return result;
		return 100;
	}

	@Override
	public String toString() {
		return "MyKey [key=" + key + "]";
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		MyKey other = (MyKey) obj;
		if (key != other.key)
			return false;
		return true;
	}

}

 

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CountDownLatch;

public class Demo2KeyCompare {
	final static Map<MyKey, Integer> count = new ConcurrentHashMap<>();
   
	public static void main(String[] args) {
    	demo2();
    }
	
	public static void demo2() {
		
		final CountDownLatch endLatch = new CountDownLatch(1);
		Runnable task = new Runnable() {
			@Override
			public void run() {
				Integer oldValue, newValue;
				for (int i = 0; i < 10; i++) {
					MyKey key = new MyKey(i);
					while (true) {
						oldValue = count.get(key);
						if (null == oldValue) {
							newValue = 1;
							if (count.putIfAbsent(key, newValue) == null) {
								break;
							}
						} else {
							newValue = oldValue + 1;
							if (count.replace(key, oldValue, newValue)) {
								break;
							}
						}
					}
					
					System.out.println(Thread.currentThread().getName() + " current key:" + key + " newValue:" + newValue);
					
				}
				endLatch.countDown();
			}

		};
		//new Thread(task).start();
		new Thread(task).start();
 
		try {
			endLatch.await();
			//System.out.println(count);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

 Output：

Thread-0 current key:MyKey [key=0] newValue:1
Thread-0 current key:MyKey [key=1] newValue:1
Thread-0 current key:MyKey [key=2] newValue:1
Thread-0 current key:MyKey [key=3] newValue:1
Thread-0 current key:MyKey [key=4] newValue:1
Thread-0 current key:MyKey [key=5] newValue:1
Thread-0 current key:MyKey [key=6] newValue:1
Thread-0 current key:MyKey [key=7] newValue:1
Thread-0 current key:MyKey [key=8] newValue:1
-----------------------------------------
cur key = 1 o.key = 0
-----------------------------------------
cur key = 2 o.key = 0
-----------------------------------------
cur key = 2 o.key = 1
-----------------------------------------
cur key = 3 o.key = 1
-----------------------------------------
cur key = 3 o.key = 2
-----------------------------------------
cur key = 4 o.key = 1
-----------------------------------------
cur key = 4 o.key = 2
-----------------------------------------
cur key = 4 o.key = 3
-----------------------------------------
cur key = 5 o.key = 1
-----------------------------------------
cur key = 5 o.key = 3
-----------------------------------------
cur key = 5 o.key = 4
-----------------------------------------
cur key = 6 o.key = 1
-----------------------------------------
cur key = 6 o.key = 3
-----------------------------------------
cur key = 6 o.key = 4
-----------------------------------------
cur key = 6 o.key = 5
-----------------------------------------
cur key = 7 o.key = 1
-----------------------------------------
cur key = 7 o.key = 3
-----------------------------------------
cur key = 7 o.key = 5
-----------------------------------------
cur key = 7 o.key = 6
-----------------------------------------
cur key = 8 o.key = 3
-----------------------------------------
cur key = 8 o.key = 5
-----------------------------------------
cur key = 8 o.key = 6
-----------------------------------------
cur key = 8 o.key = 7
-----------------------------------------
cur key = 9 o.key = 3
-----------------------------------------
cur key = 9 o.key = 5
-----------------------------------------
cur key = 9 o.key = 7
-----------------------------------------
cur key = 9 o.key = 8
Thread-0 current key:MyKey [key=9] newValue:1