![](/img/trans.png)
[英]Why is Non blocking asynchronous single-threaded faster for IO than blocking multi-threaded for some applications
[英]Why is multi-threaded Java code behaving like single-threaded?
我希望下面的代码在第一行打印出来:初始值。
public class RunnableLambda {
static String accessedByThreads = "initial value";
public static void main(String... args) {
Runnable r8 = () -> {
try {
Thread.currentThread().sleep(30);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("r8");
accessedByThreads = "from runnable lambda";
};
r8.run();
Runnable r = new Runnable() {
@Override
public void run() {
try {
Thread.currentThread().sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("r");
accessedByThreads = "from runnable anonymous";
}
};
r.run();
System.out.println("Main");
System.out.println(accessedByThreads);
}
}
因为我希望生成的线程可以在主线程之后完成。 但是,它在最后一行输出:来自可运行的匿名。
为什么?
Runnable.run()
不会启动新线程。 像在其他任何对象上一样,这是一个普通的方法调用。 您需要调用Thread.start()
方法来创建新的线程。
代替r8.run();
你需要写
Thread t1 = new Thread (r8);
t1.start(); //this creates and runs the new thread in parallel
与r.run();
相同r.run();
采用:
Thread t2 = new Thread (r);
t2.start();
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.