LoginActivity.AttemptLogin ist nicht abstrakt und überschreibt keine abstrakte Methode doInBackground (Object ...) in AsyncTask

Question

Ich versuche zu senden und meine Anmeldedaten in meiner lokalen Datenbank zu validieren, daher habe ich json, um die Einträge zu machen in JSON-Objekt und analysieren Sie es mit JSON Parser-Klasse.

Hier ist mein Code:

import android.content.Intent; 
import android.content.SharedPreferences; 
import android.graphics.Color; 
import android.os.AsyncTask; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.View; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.TextView; 
import android.widget.Toast; 

import org.apache.http.NameValuePair; 
import org.apache.http.message.BasicNameValuePair; 
import org.json.JSONException; 
import org.json.JSONObject; 
import java.util.ArrayList; 

public class LoginActivity extends AppCompatActivity { 
    EditText editEmail, editPassword, editUserName, editName, editBikeName, editBikeNo; 
    Button btnSignIn,btnRegister; 
    TextView regText, bikeText, pedText; 

    String URL= "http://192.168.225.22/android/index.php"; 

    JSONParser jsonParser=new JSONParser(); 

    int i=0,j=0; 

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

     editEmail=(EditText)findViewById(R.id.editEmail); 
     editUserName=(EditText)findViewById(R.id.editUserName); 
     editPassword=(EditText)findViewById(R.id.editPassword); 
     editName=(EditText)findViewById(R.id.editName); 
     editBikeName=(EditText)findViewById(R.id.editBikeName); 
     editBikeNo=(EditText)findViewById(R.id.editBikeNo); 
     regText=(TextView)findViewById(R.id.regText); 
     btnSignIn=(Button)findViewById(R.id.btnSignIn); 
     btnRegister=(Button)findViewById(R.id.btnRegister); 
     btnSignIn.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       AttemptLogin attemptLogin= new AttemptLogin(); 
       attemptLogin.execute(editName.getText().toString(),editPassword.getText().toString(),""); 
      } 
     }); 

     regText.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 

       if(i==0) 
       { 
        i=1; 
        editName.setVisibility(View.VISIBLE); 
        editEmail.setVisibility(View.VISIBLE); 
        btnRegister.setVisibility(View.VISIBLE); 
        bikeText.setOnClickListener(new View.OnClickListener(){ 
         public void onClick(View view){ 
          if(j==0) 
          { 
           j=1; 
           editBikeName.setVisibility(View.VISIBLE); 
           editBikeNo.setVisibility(View.VISIBLE); 
          } 
         } 
        }); 

        btnSignIn.setVisibility(View.GONE); 
        regText.setVisibility(View.GONE); 
        pedText.setOnClickListener(new View.OnClickListener(){ 
         public void onClick(View view){ 
          if(j==1) 
          { 
           j=0; 
           editBikeName.setVisibility(View.GONE); 
           editBikeNo.setVisibility(View.GONE); 
          } 
         } 
        }); 
       } 
       else{ 

        editEmail.setVisibility(View.GONE); 
        btnSignIn.setVisibility(View.VISIBLE); 
        btnRegister.setVisibility(View.GONE); 
        i=0; 

        AttemptLogin attemptLogin= new AttemptLogin(); 
        attemptLogin.execute(editName.getText().toString(),editPassword.getText().toString(),editEmail.getText().toString()); 

       } 

      } 
     }); 


    } 

    public class AttemptLogin extends AsyncTask 
    { 

     @Override 
     protected JSONObject doInBackground(String[] param) 
     { 
      String email = param[2]; 
      String password = param[1]; 
      String uname= param[0]; 

      ArrayList params = new ArrayList(); 
      params.add(new BasicNameValuePair("username", uname)); 
      params.add(new BasicNameValuePair("password", password)); 
      if(email.length()>0) 
       params.add(new BasicNameValuePair("email",email)); 

      JSONObject json = jsonParser.makeHttpRequest(URL, "POST", params); 


      return json; 

     } 

     @Override 

     protected void onPreExecute() { 

      super.onPreExecute(); 

     } 

     protected void onPostExecute(JSONObject result) { 

      // dismiss the dialog once product deleted 
      //Toast.makeText(getApplicationContext(),result,Toast.LENGTH_LONG).show(); 

      try { 
       if (result != null) { 
        Toast.makeText(getApplicationContext(),result.getString("message"),Toast.LENGTH_LONG).show(); 
       } else { 
        Toast.makeText(getApplicationContext(), "Unable to retrieve any data from server", Toast.LENGTH_LONG).show(); 
       } 
      } catch (JSONException e) { 
       e.printStackTrace(); 
      } 


     } 

    } 
} 

Jetzt bekomme ich einen Fehler, wie

Error:(250, 12) error: LoginActivity.AttemptLogin is not abstract and does not override abstract method doInBackground(Object...) in AsyncTask 

Answer 1

ersetzen:

extends AsyncTask 

mit:

extends AsyncTask<String, Void, JSONObject> 

Beachten Sie, dass die Verwendung von AsyncTask in jedem modernen Buch oder Kurs zur Entwicklung von Android-Apps abgedeckt ist.

Hier ist das AsyncTask Flussdiagramm: