线程

java 的线程相对c，c++来说基本是类似的，尤其是使用lamba都是非常快速的就能启动一个线程，相对于使用api来说，简化了很多。有几种方式可以使用：

1、使用静态内部类

java的线程类可以直接从Runnable上继承，实现 run()函数即可

static Map v_map = new ConcurrentHashMap();

    static class th1 implements Runnable{
		public void run() {
            for(int i = 0; i {
           for (String value : v_map.values()) {
            System.out.println("thread3 value = " + value);
          }
}).start();

()->的写法开始流行了，这样看起来和用起来更简单了是不是？
下面是所有代码，使用ConcurrentHashMap做实验，多个线程同时操作一个ConcurrentHashMap来演示：

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

public class threadclass {

    static Map v_map = new ConcurrentHashMap();

    static class th1 implements Runnable{


		public void run() {
            for(int i = 0; i {
           for (String value : v_map.values()) {
            System.out.println("thread3 value = " + value);
            }
		}).start();
	}
}

输出：
thread1 value = 0
thread1 value = 1
thread1 value = 2
thread1 value = 3
thread1 value = 4
thread2 value = 0
thread2 value = 1
thread1 value = 5
thread2 value = 2
thread2 value = 3
thread1 value = 6
thread2 value = 4
thread2 value = 5
thread1 value = 7
thread1 value = 8
thread2 value = 6
thread2 value = 7
thread1 value = 9
thread2 value = 8
thread2 value = 9
thread3 value = 0
thread3 value = 1
thread3 value = 2
thread3 value = 3
thread3 value = 4
thread3 value = 5
thread3 value = 6
thread3 value = 7
thread3 value = 8
thread3 value = 9