Java多线程ThreadPoolExecutor类的shutdown方法使用后，线程的任务没有执行完就terminate

我使用了ThreadPoolExecutor.execute方法执行了两个MyThread类的对象，之后调用ThreadPoolExecutor.shutdown方法。这个方法不是等待提交的任务执行完才终止吗，为什么我提交的两个任务都没有被执行呢？

String adbHead = "adb ";
                            try {
                                if (EasyScreenshotAction.DevicePickerDialog.serial ==null || EasyScreenshotAction.DevicePickerDialog.serial.length()<1) {
                                    //serial是序列号
                                }else {
                                    adbHead="adb -s "+EasyScreenshotAction.DevicePickerDialog.serial+" ";
                                }
                                String  mobileScreenshot=getCurrentTime()+"_screenshot.png";
                                String  mobileXml=getCurrentTime()+"_xml.uix";
                                //使用多线程，来达到更快的同步速度
                                MyThread screenThread=new MyThread(adbHead+"shell /system/bin/screencap -p /data/local/tmp/"+mobileScreenshot);
                                //System.out.println(adbHead+"shell /system/bin/screencap -p /data/local/tmp/"+mobileScreenshot);
                                MyThread xmlThread=new MyThread(adbHead+"shell uiautomator dump /data/local/tmp/"+mobileXml);
                                //System.out.println(adbHead+"shell uiautomator dump /data/local/tmp/"+mobileXml);
                                monitor.setTaskName("Obtaining device screenshot");
                                monitor.subTask("Taking UI XML snapshot...");
                                ThreadPoolExecutor executor = new ThreadPoolExecutor(5,5, 60, TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>());                           

//                              Runtime.getRuntime().exec(adbHead+"shell /system/bin/screencap -p /data/local/tmp/"+mobileScreenshot).waitFor();
//                              System.out.println("截图执行完毕");
                                executor.execute(xmlThread);

//                              Runtime.getRuntime().exec(adbHead+"shell uiautomator dump /data/local/tmp/"+mobileXml).waitFor();

                                executor.execute(screenThread);


                                executor.shutdown();//启动关闭，执行原来提交的任务且不接受新的任务

请问我哪里出问题了呢？

查看代码是否在run方法中，如过你那个Runtime.getRuntime().exec()必须运行，建议写在run方法里面

import java.io.IOException;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

/**
 * Test
 *
 * @author admin
 * @createTime 2020/3/19
 */
public class Test {
    public static void main(String[] args) throws IOException, InterruptedException {
        //使用多线程，来达到更快的同步速度
        MyThread screenThread = new MyThread("shell /system/bin/screencap -p /data/local/tmp/");
        MyThread xmlThread = new MyThread("shell uiautomator dump /data/local/tmp/");

        Runtime.getRuntime().exec(screenThread.value).waitFor();
        Runtime.getRuntime().exec(xmlThread.value).waitFor();

        ThreadPoolExecutor executor = new ThreadPoolExecutor(5, 5, 60, TimeUnit.SECONDS, new LinkedBlockingQueue<>());
        executor.execute(xmlThread);
        executor.execute(screenThread);
        executor.shutdown();//启动关闭，执行原来提交的任务且不接受新的任务
    }
}

class MyThread implements Runnable {
    public MyThread(String value) {
        this.value = value;
    }

    public String value;

    @Override
    public void run() {
        try {
            Runtime.getRuntime().exec(value).waitFor();
            System.out.println("你启动了线程:" + value);
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}