在android中重复启动和停止一个线程

Question

Here i have a method called Method1(), which will start a thread when the method is called odd time and stop same called even time. The below snippet works when i called the method through Button.onClick event. Is this the correct approach to pause and resume the thread ? Is my approach thread safe ?

Thread sampleThread = null;
..
..
..
private void Method1(){

    if(sampleThread == null){

        sampleThread =   new Thread(){
            @Override
            public void run() {

                while(true) {

                    Log.d(TAG,"Inside Thread");

                }
            }
        };
        sampleThread.start();

    }else {

        sampleThread.interrupt();

    }
}

Answer 1

You can use a boolean variable and set it for the while loop. like this.

Boolean isActive = true;

then,

while(isActive ) {
   Log.d(TAG,"Inside Thread");
}

So, when you change the isActive to false then the thread will stop.

Answer 2

If Method1 will be called frequently,I suggest you'd better set a flag,enable it to resume thread,and disable it to pause thread.because if you create and destroy a thread frequently,many CPU and memory will be wasted.You can use like this:

public class MyThread extends Thread{
        volatile boolean isRunning = true;//make sure use volatile keyword
        @Override
        public void run() {

            while(isRunning) {

                Log.d(TAG,"Inside Thread");

            }
        }
        public void setRunning(boolean running){
            this.isRunning = running;
        }
    };

and when you want to pause,call thread.setRunning(false) ,to restart it,call thread.setRunning(true)

If not so frequently,your solution almostly is ok,but I think you should add

sampleThread = null

after sampleThread.interrupt(); ,otherwise when you next pause it,it will interrupt a non-active thread,maybe there will throw an exception.