how to Stop a Thread in my example

Question

I have problems of searches(stackoverflow, google) and I didn't get any good results yet. I wrote a simple downloader within Thread. It (downloader) downloads my desired file and save into my android phone storage. Now I wanna stop the download with a method within my class. In other word I wanna stop downloader thread. Following is my code. How can I do this now? Please guide me. Best regards.

package com.test;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;


public class MainActivity extends Activity {

    Thread   thread;

    Handler  handler = new Handler();

    TextView txt;

    boolean  first   = true;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Button btn = (Button) findViewById(R.id.button1);
        txt = (TextView) findViewById(R.id.textView1);

        btn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                if (first) {
                    Downloader downloader = new Downloader("http://192.168.43.131/and/filmLow3.mp4");
                    first = false;
                } else {
                    if ( !thread.currentThread().isInterrupted()) {
                        thread.interrupt();
                    }
                }
            }
        });

    }


    public class Downloader {

        int downloaded = 0;


        public Downloader(final String link) {

            thread = new Thread(new Runnable() {

                @Override
                public void run() {
                    try {
                        URL url = new URL(link);
                        HttpURLConnection connection;
                        connection = (HttpURLConnection) url.openConnection();
                        connection.connect();

                        final int size = connection.getContentLength();

                        InputStream inputStream = connection.getInputStream();

                        FileOutputStream outputStream = new FileOutputStream(Base.appPath + "file.mp4");

                        byte[] buffer = new byte[8 * 1024];
                        int len = 0;

                        while ((len = inputStream.read(buffer)) != -1) {
                            downloaded += len;
                            outputStream.write(buffer, 0, len);
                            handler.post(new Runnable() {

                                @Override
                                public void run() {
                                    txt.setText(downloaded / 1024 / 1024 + " MB || " + size / 1024 / 1024 + " MB");

                                }
                            });
                        }
                        inputStream.close();
                        outputStream.close();

                    }
                    catch (IOException e) {

                        e.printStackTrace();
                    }

                }
            });
            thread.start();
        }

    }
}

https://stackoverflow.com/questions/19894607/java-how-to-stop-thread https://stackoverflow.com/questions/2491588/how-a-thread-should-close-itself-in-java — XtremeBaumer, Sep 26 '17 at 13:18
your thread doesn't stop when while loop condition turns false? — Arjit, Sep 26 '17 at 13:22
it stops. But I want to stop it while downloading and inside the loop. — Hadi, Sep 26 '17 at 13:28

score 4 · Accepted Answer · answered Sep 26 '17 at 13:19

4

thread.interrupt();

And you have to check in spinning code if thread was interrupted. For example

if( Thread.currentThread().isInterrupted()) return;

answered Sep 26 '17 at 13:19

mlecz

985
11
19

1

this is the way you should stop the thread from another one. Post code with your change, and we will see what should be changed. Also note that you cannot stop a thread immidiately. You can just send a signal, and thread should look for it. Sometimes libraries throw InterruptedException, but not always – mlecz Sep 26 '17 at 13:37
I did not know that I should not stop the Thread immediately. OK. My code is above. Please suggest the right way. – Hadi Sep 26 '17 at 13:56
In onClick, else statement should be just thread.interrupt(). And in download thread in while loop there should be if( Thread.currentThread().isInterrupted(){close all streams and; return; } – mlecz Sep 26 '17 at 14:04
1

easiest would be to make the while condition check the interupt flag : `while (!Thread.currentThread().isInterrupted() && (len = inputStream.read(buffer)) != -1)`, this will exit the while loop and closing the streams is already in place – bowmore Sep 26 '17 at 14:06
Thank you my friend. your code worked. thanks again): – Hadi Sep 26 '17 at 14:14

how to Stop a Thread in my example

1 Answers1