package com.cn.gbx; import java.util.Date;
import java.util.Random;
import java.util.Timer;
import java.util.TimerTask; public class TestThread {
static class A{
public void get() {
User user = User.getInstance();
System.out.println("A from " + Thread.currentThread().getName() + " get data:" + user.getName() + " : " + user.getPassword());
}
}
static class B{
public void get(){
User user = User.getInstance();
System.out.println("B from " + Thread.currentThread().getName() + " get data:" + user.getName() + " : " + user.getPassword());
}
}
public static void main(String[] args) {
for (int i = 0; i < 2; ++i) {
new Thread(
new Runnable() {
@Override
public void run() {
int data = new Random().nextInt();
System.out.println(Thread.currentThread().getName() + " : data = " + data);
User.getInstance().setName("name:" + data);
User.getInstance().setPassword("p:" + data);
new A().get();
new B().get();
//A,B 模块得到的都是与本线程相关联的数据， 例如数据库connection等等
}
}
).start();
}
}
} class User{ //类似单例的懒汉模式 其实ThreadLocal 就是一个Map只不过是自动将key设为本地线程
private static ThreadLocal<User> threadLocal = new ThreadLocal<User>();
private User() {}
public static User getInstance() {
User user = threadLocal.get();
if (user == null) {
user = new User();
threadLocal.set(user);
}
return user;
} private String name;
private String password;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
输出： Thread-1 : data = 1362065454
Thread-0 : data = 1208952694
A from Thread-0 get data:name:1208952694 : p:1208952694
A from Thread-1 get data:name:1362065454 : p:1362065454
B from Thread-1 get data:name:1362065454 : p:1362065454
B from Thread-0 get data:name:1208952694 : p:1208952694