同时运行多个线程android

Question

我在java中的线程有点问题。当我在MainActivity's onCreate中打开我的应用程序时，我开始在后台下载数据。假设下载将以11：46：43.641结束。

当我想使用另一个线程做某事时，我在11：46：00000开始。在run方法结束后，我必须等到11：46：43.641开始doInBackground。所以我必须等待第一个线程完成它的工作。

是否可以同时运行这两个线程？

MainActivity.java

public DownloadDataThread downloadDataThread;

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

    downloadDataThread = new DownloadDataThread(this);

    downloadDataThread.run(); 
 }

DownloadDataThread.java

public class DownloadDataThread extends Thread{

Context context;

public DownloadDataThread(Context context){
    this.context = context;
};

public DownloadDataThread(){};

public void run(){

    NetworkUtils utils = new NetworkUtils(context);

    if(!utils.isConnectingToInternet()){
    }else if(utils.isConnectingToInternet()){
        new DataFetcherTask().execute();
    }
}

public static void main(String args[]){
    DownloadDataThread obj=new DownloadDataThread();
    obj.start();
}
public void interrupt(){
    Thread.interrupted();
}

class DataFetcherTask extends AsyncTask<Void, Void, Void> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected Void doInBackground(Void... params) {
        String serverData = null;
        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpGet httpGet = new HttpGet("...");
        try {
            HttpResponse httpResponse = httpClient.execute(httpGet);
            HttpEntity httpEntity = httpResponse.getEntity();
            serverData = EntityUtils.toString(httpEntity);
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            list = new ArrayList<Game>();
            //JSONObject jsonObject = new JSONObject(serverData);
            JSONArray jsonArray = new JSONArray(serverData);

            for (int i = 0; i < jsonArray.length(); i++) {
                JSONObject jsonObjectCity = jsonArray.getJSONObject(i);

            }
        } catch (JSONException e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void aVoid) {
        super.onPostExecute(aVoid);
    }
}

这就是我在fragment中的某个地方启动另一个线程的方式：

DownloadGameDetails downloadGameDetails = new DownloadGameDetails(getActivity(),id);
        downloadGameDetails.run();

DownloadGameDetails.java

public class DownloadGameDetails extends Thread{
public Context context;
private String id;

public DownloadGameDetails(Context context,String id){
    this.context = context;
    this.id = id;
};

public DownloadGameDetails(){};

public void run(){
    NetworkUtils utils = new NetworkUtils(context);

    if(!utils.isConnectingToInternet()){
    }else if(utils.isConnectingToInternet()){
        new DataFetcherTask().execute();
    }
}

public static void main(String args[]){
    DownloadGameDetails obj = new DownloadGameDetails();
    obj.start();
}
public void interrupt(){
    Thread.interrupted();
}

class DataFetcherTask extends AsyncTask<Void, Void, Void> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected Void doInBackground(Void... params) {
        String serverData = null;
        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpGet httpGet = new HttpGet(".....);
        try {
            HttpResponse httpResponse = httpClient.execute(httpGet);
            HttpEntity httpEntity = httpResponse.getEntity();
            serverData = EntityUtils.toString(httpEntity);

        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            JSONObject jsonObject = new JSONObject(serverData);

        } catch (JSONException e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void aVoid) {
        super.onPostExecute(aVoid);
    }
}