How to finish execution of Async Task ?

Question

I need to finish the execution of an async task before I make some checks for my login.

This is my async task

@Override
    protected void onPostExecute(JSONArray jsonArray) 
    {   
        JSONObject json_data = null;
        for (int i = 0; i < jsonArray.length(); i++) {
            try {
                json_data = jsonArray.getJSONObject(i);
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            try {
                for (int j=0; j<jsonArray.length(); j++){
                    /*allMatrics.add(json_data.getString("matricNos"));
                    allPasswords.add(json_data.getString("password"));*/
                    if (user.equals(json_data.get("matricNos")) && pass.equals(json_data.get("password")))
                    {
                        ok = true;
                        System.out.println("hi i am ok");
                        break;
                    }
                }
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        System.out.println("Checking ok = "+ ok);
    }

I need to finish this async task before I Check its status and then go on for my login authentication. It is supposed to be executed on the onclick of the login button

login.setOnClickListener(new OnClickListener()
        {

            @Override
            public void onClick(View v) 
            {
                user = uedit.getText().toString();
                pass = pedit.getText().toString();


                if (user.equals(""))
                {
                    Toast error = Toast.makeText(LogInScreen.this, "Enter Details", Toast.LENGTH_SHORT);error.show();
                }
                else
                {
                    final GetMatricNos mat = new GetMatricNos();
                    mat.execute(new ServerConnector());
                    // have to finish task before enter user, have to implement logout as well
                    if ((mat.getStatus().equals(AsyncTask.Status.RUNNING))) - This has to be Status.FINISHED
                    {
                        System.out.println(ok);
                        /*  if ((allMatrics.contains(user) && (allPasswords.contains(pass)))) */
                        if (ok)
                        {               
                            Intent homescreen = new Intent(LogInScreen.this, HomeScreen.class);
                            homescreen.putExtra("username", user);
                            startActivity(homescreen);

                        }
                        else
                        {
                            AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(LogInScreen.this);
                            alertDialogBuilder.setTitle(Html.fromHtml("<font color='#D41E46'>Invalid Login Details</font>"));
                            alertDialogBuilder
                            .setMessage("The login credentials you have entered are invalid. Please try again.")
                            .setIcon(R.drawable.alert)
                            .setCancelable(false)
                            .setPositiveButton("OK",new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog,int id) {
                                    dialog.cancel();
                                }
                            });
                            AlertDialog alertDialog = alertDialogBuilder.create();
                            alertDialog.show();
                        }
                    }               
                }
            }
        });
        ActionBar actionBar = getActionBar();   
        actionBar.hide();   // To hide the actionBar on LoginScreen
    }

Now If I don't finish the task before checking it, it won't let me check the credentials that I am getting from the edit boxes, however first time if I login it doesn't make the check because the task runs when the login button is pressed, but for the second time if I login it goes through...?

Any help would be much appreciated, I tried task.cancel(true) before the check but that doesnt help...

Answer 1

If your task needs to finish executing before you do anything else then you must put the code that must wait in your onPostExecute which gets called when the task is finished