主线程都结束了，为何进程还在执行

本人在做APP性能测试的过程中，曾经遇到过一个比较尴尬的问题，主线程已经结束，但是程序依然在执行，但没有找到在执行什么，一时非常苦恼。先分享一下自己的代码，再说我找到的原因。

public static void main(String[] args) {
        String timess = args[0];
        int times = Common.getInstance().changeStringToInt(timess);
        for (int i = 0; i < times; i++) {
            Date start = Common.getInstance().getDate();
            StartApp startApp = new StartApp();// 新建启动app线程
            Logcat logcat = new Logcat();// 新建记录log线程
            PerformanceThread performanceThread = new PerformanceThread("monkey", package_name);// 性能监控
            performanceThread.start();
            startApp.start();
            logcat.start();
            execCmdAdb(command, "monkey" + getNow() + ".log");
            startApp.stopThread();
            logcat.stopLoacat();
            performanceThread.stopRecord();
            Date end = Common.getInstance().getDate();
            Common.getInstance().outputTimeDiffer(start, end, "第" + i + "次");
        }
        output("结束monkey了！");
    }

就是新启了几个线程，我猜测应该是这些线程没有很好的结束掉，导致后面出现很多问题。经过检查发现在启动APP的线程里面。这个线程做的事情就是每分钟启动一次APP，并检查一下WiFi状态，使WiFi保持开/关，十分钟反转一下WiFi的状态。主线程结束后，这些进程还在sleep()休眠状态，所以才会没找到执行的代码。分享一下这个类有问题的代码：

@Override
    public void run() {
        while (MKEY) {
            int num = Common.getInstance().getRandomInt(4);
            if (num == 1) {
                stopJuziApp();
                Common.getInstance().sleep(500);
            }
            Common.getInstance().sleep(60 * 1000);
            keepWifiONorOFF(WIFISTATUS);
            startJuziApp();
        }
    }
public void run() {
        while (WIFIKEY) {
            for (int i = 0; i < 10; i++) {
                if (WIFIKEY) {
                    break;
                }
                Common.getInstance().sleep(60 * 1000);
                keepWifiONorOFF(WIFISTATUS);
            }
            WIFISTATUS = !WIFISTATUS;// 反转WiFi状态
        }
    }

就是因为这里面的sleep()导致了之前的原因，后来我把WiFiswitch的代码改掉了，放在startAPP里面方法里面了。然后在用java多线程里面的join方法在每个线程加入到主线程，这样就可以避免主线程结束而其他线程还在运行的尴尬了。分享改之后的代码:

public static void main(String[] args) throws InterruptedException {
        String timess = args[0];
        int times = Common.getInstance().changeStringToInt(timess);
        for (int i = 0; i < times; i++) {
            Date start = Common.getInstance().getDate();
            StartApp startApp = new StartApp();// 新建启动app线程
            Logcat logcat = new Logcat();// 新建记录log线程
            PerformanceThread performanceThread = new PerformanceThread("monkey", package_name);// 性能监控
            performanceThread.start();
            startApp.start();
            logcat.start();
            execCmdAdb(command, "monkey" + getNow() + ".log");
            startApp.stopThread();
            logcat.stopLoacat();
            performanceThread.stopRecord();
            logcat.join();
            performanceThread.join();
            startApp.join();
            Date end = Common.getInstance().getDate();
            Common.getInstance().outputTimeDiffer(start, end, "第" + i + "次");
        }
        output("结束monkey了！");
    }

或者可以封装一个方法来完成：

    public static void main(String[] args) throws InterruptedException {
        String timess = args[0];
        int times = Common.getInstance().changeStringToInt(timess);
        for (int i = 0; i < times; i++) {
Date start = Common.getInstance().getDate();
StartApp startApp = new StartApp();// 新建启动app线程
Logcat logcat = new Logcat();// 新建记录log线程
PerformanceThread performanceThread = new PerformanceThread("monkey", package_name);// 性能监控
performanceThread.start();
startApp.start();
logcat.start();
execCmdAdb(command, "monkey" + getNow() + ".log");
startApp.stopThread();
logcat.stopLoacat();
performanceThread.stopRecord();
joinThread(logcat, startApp, performanceThread);
Date end = Common.getInstance().getDate();
Common.getInstance().outputTimeDiffer(start, end, "第" + i + "次");
}
output("结束monkey了！");
}

/**
* 把所有线程加入到主线程里面
* 
* @param threads
*/
public static void joinThread(Thread... threads) {
for (Thread thread : threads) {
try {
thread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}