android - 2 つの異なるアクティビティの 2 つの非同期タスクが同時に実行される

Question

私はAsyncTask自分の作業に使用していますが、1 つのアクティビティ (tab.java) とタブビュー (Feed.java) にタブがある場合、Defaultつまり最初のタブがデフォルトで表示される場合に問題が発生します。どちらのクラス ファイルにも独自の XML があります。非同期タスクを使用してサーバー応答から (tab.java) にリストを作成しています & (Tab.java) で、そのページに表示する別のサーバー応答を呼び出す必要があります。(tab.java) serverUrl から応答を受け取るたびに、アプリケーションがクラッシュします。

この種の操作を行う方法は？

ありがとうございました。

私のコード:

タブ.java:

public class Login_Header extends TabActivity
{
Button Find; 

 /** Called when the activity is first created. */

 @Override
 public void onCreate(Bundle savedInstanceState) 
 {
//To show Custom Title as image 
requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
//getWindow().requestFeature(Window.FEATURE_ACTION_BAR);
setContentView(R.layout.login_header_bar);
super.onCreate(savedInstanceState);
getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.custom_title_about_tab);




// Font size has been changed through Styles.xml for tab
    TabHost tabHost = getTabHost();

    Intent feeds = new Intent(this,Feeds.class);
    tabHost.addTab(tabHost.newTabSpec("Tab1")
                     .setIndicator("Feeds")
                     .setContent(feeds));


    Intent challenges = new Intent(this,Challenges.class);
    tabHost.addTab(tabHost.newTabSpec("Tab2")
                     .setIndicator("Challenges")
                     .setContent(challenges));

    Intent friends = new Intent(this,Friends.class);
    tabHost.addTab(tabHost.newTabSpec("Tab3")
                     .setIndicator("Friends")
                     .setContent(friends));

   Intent group = new Intent(this,Groups.class);
   tabHost.addTab(tabHost.newTabSpec("Tab4")
                     .setIndicator("Groups")
                     .setContent(group));

   Intent details = new Intent(this,Details.class);
   tabHost.addTab(tabHost.newTabSpec("Tab5")
                     .setIndicator("Details")
                     .setContent(details));

    tabHost.setCurrentTab(0);



   Find.setOnClickListener(new OnClickListener() 
   {
   @Override
   public void onClick(View v) 
   {
     // TODO Auto-generated method stub

     Intent find = new Intent(Login_Header.this,Find.class);
    startActivity(find);
   }
    });
   //To call async task
   callNotificationCount();
  }
private void callNotificationCount() 
{
    new NotificationCount_Async().execute("");
}



private class  NotificationCount_Async extends AsyncTask<String, Void, String>
{

      @Override
      protected String doInBackground(String... params)
      {
          try 
            {
                URL url=new URL(getString(R.string.WebServiceURL)+"/notifications/notificationcount");
                HttpPost httppost = new HttpPost(url.toString());
                HttpResponse responsePOST = LoginPage.httpClient.execute(httppost); 
                HttpEntity resEntity = responsePOST.getEntity();
                InputStream instream = resEntity.getContent();
                String result = convertStreamToString(instream);

                Log.i("User Feed",result);
                return result;
            }
              catch(Exception ex) 
              { 
                   Log.e("error", "error", ex);
                   return null;
              }
         }

        @Override
        protected void onPostExecute(String result)
          {
            try {
                     JSONObject json = new JSONObject(result);
                     //Below  code is for user count

                     JSONObject userNotificationjson = json.getJSONObject("user_notification");
                     if(json.has("user_notification"))
                     {
                         String userCount = userNotificationjson.getString("count");
                         int Count = Integer.parseInt(userCount);
                         if(Count > 0)
                         {
                             LinearLayout llUserCount = (LinearLayout)findViewById(R.id.llUserCount);
                             TextView userCountTextView =(TextView)findViewById(R.id.txtUserCount);
                             llUserCount.setVisibility(View.VISIBLE);
                             userCountTextView.setText(userCount);
                        }
                    }


           }
     private  String convertStreamToString(InputStream is)
      {
        //code
 }

`

私の既定のタブ フィード アクティビティ。

  public class Feeds extends Activity 
  {
SessionManager session;
String custom_phpsess_id,logged_in_id_User,returnString;

// Declare Variables
JSONObject jsonobject;
JSONArray jsonarray;
ListView listview;
ListViewAdapter adapter;
ProgressDialog mProgressDialog;
ArrayList<HashMap<String, String>> arraylist;

 static  String FIRST_NAME = "firstname";
 static  String LAST_NAME = "lastname";
 static  String ACTION = "action";
// static  String ACTIVITY_NAME = "activity_name";
 static  String IMAGE_URL = "image";
 static  String USER_ID = "user_id";
 static  String ACTIVITY_NAME = "activityname";

 String strUrl = =new URL(getString(R.string.WebServiceURL)+"/users/userfeeds";
 ListView mListView;
 String id_User;

 public void onCreate(Bundle savedInstanceState) 
 {
    super.onCreate(savedInstanceState);

    // Get the view from feeds.xml
     setContentView(R.layout.feeds);

    session = new SessionManager(getApplicationContext());

    //To get values from session
    HashMap<String, String> User = session.getUserDetails();

    logged_in_id_User = User.get(SessionManager.KEY_ID);
    custom_phpsess_id = User.get(SessionManager.KEY_USE);

    // Creating a new non-ui thread task to download json data 
    // Execute DownloadJSON AsyncTask

    Log.i("On Create", "Main On Create");
    new DownloadJSON().execute();
  }

// DownloadJSON AsyncTask
private class DownloadJSON extends AsyncTask<Void, Void, Void> 
{
    @Override
    protected void onPreExecute() 
    {
        Log.i("On DownloadJSON", "onPreExecute");
        super.onPreExecute();
        // Create a progressdialog
        mProgressDialog = new ProgressDialog(Feeds.this);
        // Set progressdialog title
        mProgressDialog.setTitle("");
        // Set progressdialog message
        mProgressDialog.setMessage("Loading...");
        mProgressDialog.setIndeterminate(false);
        // Show progressdialog
        mProgressDialog.show();
    }

    @Override
    protected Void doInBackground(Void... params) 
    {
        Log.i("On doInBackground", "doInBackground");
        // Create the array 
        arraylist = new ArrayList<HashMap<String, String>>();
        // Retrive JSON Objects from the given website URL in JSONfunctions.class
        jsonobject = JSONfunctions
                .getJSONfromURL(strUrl);
        Log.i("On doInBackground-jsonObject", jsonobject.toString());

        try 
        {
            // Locate the array name
            jsonarray = jsonobject.getJSONArray("userdata");

            Log.i("On doInBackground-jsonarray", jsonarray.toString());


            for (int i = 0; i < jsonarray.length(); i++) 
            {

                    HashMap<String, String> map = new HashMap<String, String>();
                    jsonobject = jsonarray.getJSONObject(i);
                    // Retrive JSON Objects
                    if(jsonobject.getString("actions").equals("Completed"))
                    {
                        map.put("firstname", jsonobject.getString("first_name"));
                        map.put("lastname", jsonobject.getString("last_name"));
                        map.put("action", jsonobject.getString("actions"));
                        map.put("image", jsonobject.getString("file_name"));
                        map.put("user_id", jsonobject.getString("id_user"));
                        map.put("activityname", jsonobject.getString("activity_name"));

                        Log.i("On doInBackground-Map", map.toString());
                        // Set the JSON Objects into the array
                        arraylist.add(map);
                    }
            } 
        }
        catch (JSONException e) 
        {
            Log.i("On doInBackground-JSONException", e.toString());
            Log.e("Error", e.getMessage());
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void args) 
    {
        Log.i("On onPostExecute", "ON post exe");
        // Locate the listview in listview_main.xml
        listview = (ListView)findViewById(R.id.listview);

        Log.i("On onPostExecute-onPostExecute-arraylist", arraylist.toString());
        // Pass the results into ListViewAdapter.java
        adapter = new ListViewAdapter(Feeds.this, arraylist);
        Log.i("On onPostExecute-onPostExecute-Adapter", adapter.toString());
        // Binds the Adapter to the ListView
        listview.setAdapter(adapter);
        // Close the progressdialog
        mProgressDialog.dismiss();
    }
}
 }

ログキャット:

06-24 11:44:11.412: W/SingleClientConnManager(422): Invalid use of SingleClientConnManager: connection still allocated.
06-24 11:44:11.412: W/SingleClientConnManager(422): Make sure to release the connection before allocating another one.
06-24 11:44:11.531: E/log_tag(422): Error in http connection java.net.SocketException: Socket closed
06-24 11:44:11.551: E/log_tag(422): Error converting result java.lang.NullPointerException
06-24 11:44:11.571: E/log_tag(422): Error parsing data org.json.JSONException: End of input at character 0 of 
06-24 11:44:11.911: W/dalvikvm(422): threadid=10: thread exiting with uncaught exception (group=0x40014760)
06-24 11:44:12.701: E/AndroidRuntime(422): FATAL EXCEPTION: AsyncTask #2
06-24 11:44:12.701: E/AndroidRuntime(422): java.lang.RuntimeException: An error occured while executing doInBackground()
06-24 11:44:12.701: E/AndroidRuntime(422):  at android.os.AsyncTask$3.done(AsyncTask.java:266)
06-24 11:44:12.701: E/AndroidRuntime(422):  at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
06-24 11:44:12.701: E/AndroidRuntime(422):  at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
06-24 11:44:12.701: E/AndroidRuntime(422):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
06-24 11:44:12.701: E/AndroidRuntime(422):  at java.util.concurrent.FutureTask.run(FutureTask.java:137)
06-24 11:44:12.701: E/AndroidRuntime(422):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1081)
06-24 11:44:12.701: E/AndroidRuntime(422):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:574)
06-24 11:44:12.701: E/AndroidRuntime(422):  at java.lang.Thread.run(Thread.java:1020)
06-24 11:44:12.701: E/AndroidRuntime(422): Caused by: java.lang.NullPointerException
06-24 11:44:12.701: E/AndroidRuntime(422):  at com.si.gtc.Feeds$DownloadJSON.doInBackground(Feeds.java:97)
06-24 11:44:12.701: E/AndroidRuntime(422):  at com.si.gtc.Feeds$DownloadJSON.doInBackground(Feeds.java:1)
06-24 11:44:12.701: E/AndroidRuntime(422):  at android.os.AsyncTask$2.call(AsyncTask.java:252)
06-24 11:44:12.701: E/AndroidRuntime(422):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
06-24 11:44:12.701: E/AndroidRuntime(422):  ... 4 more
06-24 11:44:13.661: E/WindowManager(422): Activity com.si.gtc.Login_Header has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@40feb498 that was originally added here
06-24 11:44:13.661: E/WindowManager(422): android.view.WindowLeaked: Activity com.si.gtc.Login_Header has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@40feb498 that was originally added here
06-24 11:44:13.661: E/WindowManager(422):   at android.view.ViewRoot.<init>(ViewRoot.java:285)
06-24 11:44:13.661: E/WindowManager(422):   at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:152)
06-24 11:44:13.661: E/WindowManager(422):   at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:95)
06-24 11:44:13.661: E/WindowManager(422):   at android.view.Window$LocalWindowManager.addView(Window.java:526)
06-24 11:44:13.661: E/WindowManager(422):   at android.app.Dialog.show(Dialog.java:269)
06-24 11:44:13.661: E/WindowManager(422):   at com.si.gtc.Feeds$DownloadJSON.onPreExecute(Feeds.java:85)
06-24 11:44:13.661: E/WindowManager(422):   at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:549)
06-24 11:44:13.661: E/WindowManager(422):   at android.os.AsyncTask.execute(AsyncTask.java:499)
06-24 11:44:13.661: E/WindowManager(422):   at com.si.gtc.Feeds.onCreate(Feeds.java:66)
06-24 11:44:13.661: E/WindowManager(422):   at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1048)
06-24 11:44:13.661: E/WindowManager(422):   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1712)
06-24 11:44:13.661: E/WindowManager(422):   at android.app.ActivityThread.startActivityNow(ActivityThread.java:1589)
06-24 11:44:13.661: E/WindowManager(422):   at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:130)
06-24 11:44:13.661: E/WindowManager(422):   at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:342)
06-24 11:44:13.661: E/WindowManager(422):   at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:676)
06-24 11:44:13.661: E/WindowManager(422):   at android.widget.TabHost.setCurrentTab(TabHost.java:345)
06-24 11:44:13.661: E/WindowManager(422):   at android.widget.TabHost.addTab(TabHost.java:235)
06-24 11:44:13.661: E/WindowManager(422):   at com.si.gtc.Login_Header.onCreate(Login_Header.java:104)
06-24 11:44:13.661: E/WindowManager(422):   at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1048)
06-24 11:44:13.661: E/WindowManager(422):   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1712)
06-24 11:44:13.661: E/WindowManager(422):   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1764)
06-24 11:44:13.661: E/WindowManager(422):   at android.app.ActivityThread.access$1500(ActivityThread.java:122)
06-24 11:44:13.661: E/WindowManager(422):   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1002)
06-24 11:44:13.661: E/WindowManager(422):   at android.os.Handler.dispatchMessage(Handler.java:99)
06-24 11:44:13.661: E/WindowManager(422):   at android.os.Looper.loop(Looper.java:132)
06-24 11:44:13.661: E/WindowManager(422):   at android.app.ActivityThread.main(ActivityThread.java:4025)
06-24 11:44:13.661: E/WindowManager(422):   at java.lang.reflect.Method.invokeNative(Native Method)
06-24 11:44:13.661: E/WindowManager(422):   at java.lang.reflect.Method.invoke(Method.java:491)
06-24 11:44:13.661: E/WindowManager(422):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
06-24 11:44:13.661: E/WindowManager(422):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
06-24 11:44:13.661: E/WindowManager(422):   at dalvik.system.NativeStart.main(Native Method)

Answer 1

doInBackgroundAsyncTaskのメソッド内で、次のように閉じることを忘れないでInputStreamください。

     try 
        {
            URL url=new URL(getString(R.string.WebServiceURL)+"/notifications/notificationcount");
            HttpPost httppost = new HttpPost(url.toString());
            HttpResponse responsePOST = LoginPage.httpClient.execute(httppost); 
            HttpEntity resEntity = responsePOST.getEntity();
            InputStream instream = resEntity.getContent();
            String result = convertStreamToString(instream);

            Log.i("User Feed",result);
            return result;
        }
        catch(Exception ex) 
        { 
               Log.e("error", "error", ex);
               return null;
        }
        finally{
               instream.close();
        }

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