java多线程 单范例多线程的安全

java多线程 单实例多线程的安全

ThreadLocal变量--解决变量安全问题的终极解决之道

package 多线程;

class Runner implements Runnable {
	ThreadLocal<Integer> threadLocal = new ThreadLocal<Integer>();

	@Override
	public void run() {
		for (int i = 1; i <= 10; i++) {
			if (threadLocal.get() == null) {
				threadLocal.set(new Integer(0));
			}
			int x = (Integer) threadLocal.get();
			x = x + i;
			threadLocal.set(x);
			try {
				Thread.sleep(1000);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			System.out.println(Thread.currentThread().getName() + "\tsum="
					+ threadLocal.get());
		}
	}
}

 

 

把数据存储存储到threadLocal里

 

package 多线程;

public class ThreadLocalTest {

	public static void main(String[] args) {
		Runnable run = new Runner();
		Thread ta = new Thread(run,"threadA");
		Thread tb = new Thread(run,"threadB");
		ta.start();
		tb.start();
	}
}

 调用之后，安全输出