package chapter2;

import java.util.HashMap;
import java.util.Map;

/**
 * Created by 13 on 2017年5月4日.
 */
public class HashMapMultiThread {
 static Map<String, String> map = new HashMap<String, String>();

 public static class AddThread implements Runnable {

 /**
 * When an object implementing interface <code>Runnable</code> is used
 * to create a thread, starting the thread causes the object's
 * <code>run</code> method to be called in that separately executing
 * thread.
 * <p/>
 * The general contract of the method <code>run</code> is that it may
 * take any action whatsoever.
 *
 * @see Thread#run()
 */
 int start = 0;

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

 @Override
 public void run() {
 for (int i = start; i < 100000; i += 2) {
 map.put(Integer.toString(i), Integer.toBinaryString(i));
 }
 }
 }

 /**
 * HashMap是一个线程不安全的容器,多线程操作时会出现冲突
 *
 * jdk7下谨慎运行此方法,可能会导致电脑死机,jdk8中问题已修复
 *
 * @param args
 * @throws InterruptedException
 */
 public static void main(String args[]) throws InterruptedException {
 Thread thread1 = new Thread(new HashMapMultiThread.AddThread(0));
 Thread thread2 = new Thread(new HashMapMultiThread.AddThread(1));
 thread1.start();
 thread2.start();
 thread1.join();
 thread2.join();
 System.out.println(map.size());
 }
}