Java 如何等待当前线程执行并完全执行另一个线程

所需输出：

public class MainClass{
    public static void main(String[] args) {
       try{ 
        Thread1 thread1 = new Thread1();
        Thread2 thread1 = new Thread2();
        thread1.start();
        Thread.sleep(3000);
        thread1.join();
        thread2.start();
     }catch(Exception e){
     }

   }
}

---

但是没有把上面的内容输出。

您的输出表明您实际拥有的是什么

From testFun1() 1
From testFun1() 2
From testFun1() 3
From testFun2() 20
From testFun2() 21
From testFun2() 22
From testFun2() 23
From testFun2() 24
From testFun2() 25
From testFun1() 4
From testFun1() 5
From testFun1() 6
From testFun1() 7
From testFun1() 8
From testFun1() 9
From testFun1() 10

---

如果最后两行是thread1的另一种方式，则thread1将在thread2启动之前运行到完成状态。

对

thread1.join（）

的调用将一直等到

thread1

完成它正在执行的操作。因此，您的两个线程将一个接一个地运行。

查看该类。它的类javadoc有一个协调线程的示例。

这里是我提出的，任何建议/改进/错误实践

thread1.start();

Thread.sleep(3000);

thread2.start();

thread1.join();

类Thread1.java

public class App {

    public static void main(String[] args) {
        Thread1 thread1 = new Thread1();
        Thread2 thread2 = new Thread2();

        try {
            thread1.start();
            Thread.sleep(500);
            synchronized (thread1) {
                thread1.waiting = true;
                thread2.start();
                thread2.join();
                thread1.waiting = false;
                thread1.notify();
            }
        } catch (Exception e) {
            //TODO actually handle exception
        }
    }
}

---

问候

你能调整格式化来删除空白行吗？PLS？你的代码没有编译（缺少catch块，thule1声明两次……）。请发布一个工作示例。@NathanHughes也许他们试图理解事情。你真正想要什么？是否希望THEAD1和THEAD2的输出散布，或者希望THEAD2完全在线程1的中间运行？当你说“所需输出”时，我想你的意思并不完全是这样，因为如果没有更多的协调，几乎不可能保证这种输出。我想他是说他没有得到输出，但想得到。与其发布答案，不如编辑你原来的问题。这将使评论变得更加简单。

public class App {

    public static void main(String[] args) {
        Thread1 thread1 = new Thread1();
        Thread2 thread2 = new Thread2();

        try {
            thread1.start();
            Thread.sleep(500);
            synchronized (thread1) {
                thread1.waiting = true;
                thread2.start();
                thread2.join();
                thread1.waiting = false;
                thread1.notify();
            }
        } catch (Exception e) {
            //TODO actually handle exception
        }
    }
}

public class Thread1 extends Thread {
    boolean waiting = false;

    public void run() {
        testFun1();
    }

    public void testFun1() {
        for (int i = 1; i < 10; i++) {
            synchronized (this) {
                while (waiting) {
                    try {
                        wait();
                    } catch (Exception e) {
                        //TODO Handle exception
                    }
                }
            }
            try {
                Thread.sleep(100);
                System.out.println("From testFun1() = " + i);
            } catch (Exception e) {
                //TODO Handle exception

            }
        }
    }
}

public class Thread2 extends Thread {

    public void run() {
        testFun2();
    }

    public void testFun2() {
        try {
            for (int i = 20; i <= 25; i++) {
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    //catch
                }
                System.out.println("From testFun2() = " + i);
            }

        } catch (Exception e) {
            //TODO do something
        }

    }
}

C:\Java\jdk1.6.0_25\bin\java -Didea.launcher.port=7543 "-Didea.launcher.bin.path=C:\Program Files\JetBrains\IntelliJ IDEA 10.5.1\bin" -Dfile.encoding=UTF-8 -classpath "C:\Java\jdk1.6.0_25\jre\lib\alt-rt.jar;C:\Java\jdk1.6.0_25\jre\lib\alt-string.jar;C:\Java\jdk1.6.0_25\jre\lib\charsets.jar;C:\Java\jdk1.6.0_25\jre\lib\deploy.jar;C:\Java\jdk1.6.0_25\jre\lib\javaws.jar;C:\Java\jdk1.6.0_25\jre\lib\jce.jar;C:\Java\jdk1.6.0_25\jre\lib\jsse.jar;C:\Java\jdk1.6.0_25\jre\lib\management-agent.jar;C:\Java\jdk1.6.0_25\jre\lib\plugin.jar;C:\Java\jdk1.6.0_25\jre\lib\resources.jar;C:\Java\jdk1.6.0_25\jre\lib\rt.jar;C:\Java\jdk1.6.0_25\jre\lib\ext\dnsns.jar;C:\Java\jdk1.6.0_25\jre\lib\ext\localedata.jar;C:\Java\jdk1.6.0_25\jre\lib\ext\sunjce_provider.jar;C:\Java\jdk1.6.0_25\jre\lib\ext\sunmscapi.jar;C:\Java\jdk1.6.0_25\jre\lib\ext\sunpkcs11.jar;C:\IdeaProjects\PracticeModule\target\classes;C:\Program Files\JetBrains\IntelliJ IDEA 10.5.1\lib\idea_rt.jar" com.intellij.rt.execution.application.AppMain jmhp.core.App
From testFun1() = 1
From testFun1() = 2
From testFun1() = 3
From testFun1() = 4
From testFun1() = 5
From testFun2() = 20
From testFun2() = 21
From testFun2() = 22
From testFun2() = 23
From testFun2() = 24
From testFun2() = 25
From testFun1() = 6
From testFun1() = 7
From testFun1() = 8
From testFun1() = 9