package base;

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

public class HashMapMultiThread {
	// 1、运行正常,结果正常
	// 2、运行正常,结果错误
	//3、若是JDK1.8以下,程序会无法结束,由于多线程冲突链表已经遭到破坏,成了环形
	//如k1、k2互为对象的next元素,这样next引用遍历就成了死循环。
	//JDK1.8也会导致内部数据不一致。
	//private static Map<String, String> map = new HashMap<String, String>();

	private static ConcurrentHashMap<String, String> map = new ConcurrentHashMap<String, String>();
	public static void main(String[] args) throws InterruptedException {
		Thread t = new Thread(new AddThread(0));
		Thread t1 = new Thread(new AddThread(1));
		t.start();
		t1.start();
		t.join();
		t1.join();
		System.out.println("map size: " + map.size());
	}

	public static class AddThread implements Runnable {
		int start = 0;

		public AddThread(int start) {
			super();
			this.start = start;
		}

		@Override
		public void run() {
			for (int i = start; i < 10000; i++) {
				map.put(Integer.toString(i), Integer.toBinaryString(i));
			}
		}

	}

}