一手遮天 Android - 异步和多线程: Thread 演示 interrupt() 的用法
一手遮天 Android - 异步和多线程: Thread 演示 interrupt() 的用法
示例如下:
/async/ThreadDemo4.java
/**
* 演示 Thread 的 interrupt() 的用法
*
* 1、关于停止线程的方法，如 stop(), destroy(), suspend(), resume() 都是有问题的，不要再用了
* 2、需要停止线程的话请用 interrupt()，然后自己写相关的逻辑
* 3、调用了线程的 interrupt() 后，分两种情况，一种是会触发 InterruptedException 异常，另一种则不会，参见下面的 sample1 和 sample2 示例
* 4、注：如果线程中有 io 阻塞的话，先要把这个 io 干掉
*/
package com.webabcd.androiddemo.async;
import android.os.SystemClock;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import com.webabcd.androiddemo.R;
public class ThreadDemo4 extends AppCompatActivity {
private final String LOG_TAG = "ThreadDemo4";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_async_threaddemo4);
// 如果线程在调用 Object 的 wait() 方法，或者自己的 join(), sleep() 方法阻塞的过程中，调用了 interrupt() 方法，则会触发 InterruptedException 异常
// 注：调用 interrupt() 方法后，线程的 interrupted 状态会被置为 true，而在触发了 InterruptedException 异常后，线程的 interrupted 状态会被置为 false
sample1();
// 非 wait(), join(), sleep() 阻塞中，调用了 interrupt() 方法，则不会触发 InterruptedException 异常，而是将线程的 interrupted 置为 true（只是设置这个状态而已，没有别的逻辑）
// 此之后通过线程对象 thread.isInterrupted() 获取到的值为 true
// 再之后第一次通过线程类 Thread.interrupted() 获取到的值为 true，与此同时会将 interrupted 置为 false
// 再之后通过 thread.isInterrupted() 和 Thread.interrupted() 获取到的值均为 false
//sample2();
}
// 本示例的执行结果如下：
/**
* thread1 isInterrupted:true
* sample1 执行完了
* thread1:java.lang.InterruptedException
* thread1 isInterrupted: false
* thread1 interrupted: false
* thread1 执行完了
*/
private void sample1() {
Thread thread1 = new Thread(new Runnable() {
@Override
public void run() {
while (true) {
try {
// sleep 过程中被 interrupt() 则触发 InterruptedException 异常
// catch 到 InterruptedException 异常后退出线程即可
Thread.sleep(1000);
} catch (InterruptedException e) {
Log.d(LOG_TAG, "thread1:" + e.toString());
// 触发了 InterruptedException 异常后，线程的 interrupted 状态会被置为 false
Log.d(LOG_TAG, "thread1 isInterrupted: " + Thread.currentThread().isInterrupted());
Log.d(LOG_TAG, "thread1 interrupted: " + Thread.interrupted());
break;
}
}
Log.d(LOG_TAG, "thread1 执行完了");
}
});
thread1.setDaemon(true);
thread1.setName("thread1");
thread1.start();
try {
Thread.sleep(100);
// 调用 thread1 的 interrupt() 方法后，thread1 的 interrupted 状态会被置为 true
thread1.interrupt();
Log.d(LOG_TAG, "thread1 isInterrupted:" + thread1.isInterrupted());
} catch (InterruptedException e) {
}
Log.d(LOG_TAG, "sample1 执行完了");
}
// 本示例的执行结果如下：
/**
* sample2 执行完了
* thread2 isInterrupted:false
* thread2 isInterrupted:false
* thread2 isInterrupted:false
* thread2 interrupted: false
* thread2 isInterrupted:false
* thread2 isInterrupted:false
* thread2 isInterrupted:false
* thread2 isInterrupted:false
* thread2 isInterrupted:false
* thread2 interrupted: false
* thread2 isInterrupted:false
* thread2 isInterrupted:true // interrupt() 之后，isInterrupted 为 true
* thread2 isInterrupted:true
* thread2 isInterrupted:true
* thread2 isInterrupted:true
* thread2 interrupted: true // interrupt() 之后，第一次 Thread.interrupted() 的值为 true，与此同时会将 interrupted 置为 false
* thread2 isInterrupted:false // 再之后 thread.isInterrupted() 和 Thread.interrupted() 值均为 false
* thread2 isInterrupted:false
* thread2 isInterrupted:false
* thread2 isInterrupted:false
* thread2 isInterrupted:false
* thread2 interrupted: false
* thread2 isInterrupted:false
* thread2 isInterrupted:false
* thread2 isInterrupted:false
* thread2 isInterrupted:false
* thread2 isInterrupted:false
* thread2 interrupted: false
* thread2 isInterrupted:false
* thread2 isInterrupted:false
* thread2 isInterrupted:false
* ......
*/
private void sample2() {
final Thread thread2 = new Thread(new Runnable() {
@Override
public void run() {
// 非 wait(), join(), sleep() 阻塞中，调用了 interrupt() 方法，则将线程的 interrupted 置为 true
long timePrev = SystemClock.elapsedRealtime() / 1000;
while (true) {
long timeCurrent = SystemClock.elapsedRealtime() / 1000;
if (timePrev != timeCurrent) {
// 在 interrupt() 之后
// thread.isInterrupted() 的值为 true
// 第一次 Thread.interrupted() 的值为 true，与此同时会将 interrupted 置为 false
// 再之后 thread.isInterrupted() 和 Thread.interrupted() 值均为 false
Log.d(LOG_TAG, "thread2 interrupted: " + Thread.interrupted()); // 通过 Thread.interrupted() 判断，如果是 true，则退出线程即可
timePrev = timeCurrent;
}
}
}
});
thread2.setDaemon(true);
thread2.setName("thread2");
thread2.start();
Thread myThread = new Thread(new Runnable() {
@Override
public void run() {
int i = 0;
while (true) {
try {
Thread.sleep(200);
if (i++ == 9) {
thread2.interrupt();
}
} catch (InterruptedException e) {
}
Log.d(LOG_TAG, "thread2 isInterrupted:" + thread2.isInterrupted());
}
}
});
myThread.setDaemon(true);
myThread.setName("myThread");
myThread.start();
Log.d(LOG_TAG, "sample2 执行完了");
}
}
/layout/activity_async_threaddemo4.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="详见 java 代码" />
</LinearLayout>
