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);
}
}
}