ThreadLocal实现线程范围内共享

　　线程范围内共享，即是对相同一段代码，在不同的模块调用时使用一份数据，而在另外一个线程中又使用另外一份数据。

　　ThreadLocal使用set方法为一个新的线程增加一条记录，key是各自的线程，value为set进去的值，也就是共享的值。ThreadLocal.clear()清空记录。

　　JAVA代码

public class TraditionalThreadSocpeShare {
    private static Map<Thread, Integer> threadLocal = new HashMap<Thread, Integer>();
    public static void main(String[] args) {
        for (int i = 0; i < 2; i++) {
            new Thread(new Runnable() {
                public void run() {
                    int data = new Random().nextInt();
                    threadLocal.put(Thread.currentThread(), data);
                    System.out.println(Thread.currentThread().getName()
                            + " data value " + data);
                    new A().get();
                    new B().get();
                }

            }).start();
        }
    }

    static class A {
        public void get() {
            int data = threadLocal.get(Thread.currentThread());
            System.out.println("A from " + Thread.currentThread().getName()
                    + " data value " + data);
        }
    }

    static class B {
        public void get() {
            int data = threadLocal.get(Thread.currentThread());
            System.out.println("B from " + Thread.currentThread().getName()
                    + " data value " + data);
        }
    }
}