Rnosmodule java 31 error method does not override or implement a method from a supertype

I have looked all around but can’t figure out why I’m getting the error

error: method does not override or implement a method from a supertype

This highlights the two @Overrides I have in a method (subroutine?). Here’s my MainActivity.java — the part of the code it occurs in the queryBooks() method at the end — the @Overrides are both underlined red.

package com.example.batman.myapplication;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.support.v4.view.MenuItemCompat;
//import android.support.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.ShareActionProvider;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;


import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.JsonHttpResponseHandler;

import org.json.JSONObject;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity implements View.OnClickListener, AdapterView.OnItemClickListener {
    TextView mainTextView;
    EditText mainEditText;
    ListView mainListView;
    ArrayAdapter mArrayAdapter;
//  ArrayList<String> mNameList = new ArrayList<String>();
    ArrayList mNameList = new ArrayList();
    android.support.v7.widget.ShareActionProvider mShareActionProvider;

    // This is for internet stuff
    private static final String QUERY_URL = "http://openlibrary.org/search.json?q=";


    // Setting up the storage of data
    private static final String PREFS = "prefs";
    private static final String PREF_NAME = "name";
    SharedPreferences mSharedPreferences;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // 1. Access the TextView defined in layout XML
        // and then set its text
        mainTextView = (TextView) findViewById(R.id.main_textview);
//      mainTextView.setText("Set in Java!");

        Button mainButton;
        mainButton = (Button) findViewById(R.id.main_button);
        mainButton.setOnClickListener(this);

        // 3.  Access the EditText defined in layout XML
        mainEditText = (EditText) findViewById(R.id.main_edittext);

        // 4. Access the ListView
        mainListView = (ListView) findViewById(R.id.main_listview);
        // Create an ArrayAdapter for the ListView
        mArrayAdapter = new ArrayAdapter(this,
                android.R.layout.simple_list_item_1,
                mNameList);
        // Set the ListView to use the ArrayAdapter
        mainListView.setAdapter(mArrayAdapter);

        // 5. Set this activity to react to list items being pressed
        mainListView.setOnItemClickListener(this);

        // 7. Greet the user, or ask for their name if new
        displayWelcome();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu.
        // Adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);

        // Access the Share Item defined in menu XML
        MenuItem shareItem = menu.findItem(R.id.menu_item_share);

        // Access the object responsible for
        // putting together the sharing submenu
        if (shareItem != null) {
            mShareActionProvider = (ShareActionProvider) MenuItemCompat.getActionProvider(shareItem);
        }

        // Create an Intent to share your content
        setShareIntent();

        return true;
    }

    private void setShareIntent() {

        if (mShareActionProvider != null) {

            // create an Intent with the contents of the TextView
            Intent shareIntent = new Intent(Intent.ACTION_SEND);
            shareIntent.setType("text/plain");
            shareIntent.putExtra(Intent.EXTRA_SUBJECT, "Android Development");
            shareIntent.putExtra(Intent.EXTRA_TEXT, mainTextView.getText());

            // Make sure the provider knows
            // it should work with that Intent
            mShareActionProvider.setShareIntent(shareIntent);
        }
    }

    @Override
    public void onClick(View v) {
//      // Take what was typed into the EditText
//      // and use in TextView
//      mainTextView.setText(mainEditText.getText().toString() + ".");
//
//      // Also add that value to the list shown in the ListView
//      mNameList.add(mainEditText.getText().toString());
//      mArrayAdapter.notifyDataSetChanged();
//      // 6. The text you'd like to share has changed,
//      // and you need to update
//      setShareIntent();
//
//      if(v == mainEditText) {
//          mainEditText.setText("");
//      }

        // 9. Take what was typed into the EditText and use in search
        // (the above is commented out, per tutorial part 3 - this takes its place as input
        queryBooks(mainEditText.getText().toString());
//      mainEditText.setText("");
    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

        // Log the item's position and contents
        // to the console in Debug
        Log.d("My Application", position + ": " + mNameList.get(position));
    }

    public void displayWelcome() {

        // Access the device's key-value storage
        mSharedPreferences = getSharedPreferences(PREFS, MODE_PRIVATE);

        // Read the user's name,
        // or an empty string if nothing found
        String name = mSharedPreferences.getString(PREF_NAME, "");

        if (name.length() > 0) {

            // If the name is valid, display a Toast welcoming them
            Toast.makeText(this, "Welcome back, " + name + "!", Toast.LENGTH_LONG).show();
        } else {

            // otherwise, show a dialog to ask for their name
            AlertDialog.Builder alert = new AlertDialog.Builder(this);
            alert.setTitle("Hello!");
            alert.setMessage("What is your name?");

            // Create EditText for entry
            final EditText input = new EditText(this);
            alert.setView(input);

            // Make an "OK" button to save the name
            alert.setPositiveButton("OK", new DialogInterface.OnClickListener() {

                public void onClick(DialogInterface dialog, int whichButton) {

                    // Grab the EditText's input
                    String inputName = input.getText().toString();

                    // Put it into memory (don't forget to commit!)
                    SharedPreferences.Editor e = mSharedPreferences.edit();
                    e.putString(PREF_NAME, inputName);
                    e.commit();

                    // Welcome the new user
                    Toast.makeText(getApplicationContext(), "Welcome, " + inputName + "!", Toast.LENGTH_LONG).show();
                }
            });
        // Make a "Cancel" button
        // that simply dismisses the alert
                    alert.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {

                        public void onClick(DialogInterface dialog, int whichButton) {}
                    });

            alert.show();
    }
    }

    // Internet stuff
    private void queryBooks(String searchString) {

        // Prepare your search string to be put in a URL
        // It might have reserved characters or something
        String urlString = "";
        try {
            urlString = URLEncoder.encode(searchString, "UTF-8");
        } catch (UnsupportedEncodingException e) {

            // if this fails for some reason, let the user know why
            e.printStackTrace();
            Toast.makeText(this, "Error: " + e.getMessage(), Toast.LENGTH_LONG).show();
        }

        // Create a client to perform networking
        AsyncHttpClient client = new AsyncHttpClient();

        // Have the client get a JSONArray of data
        // and define how to respond
        client.get(QUERY_URL + urlString,
                new JsonHttpResponseHandler() {

                    @Override // THIS METHOD DOES NOT OVERRIDE METHOD FROM ITS SUPERCLASS ??
                    public void onSuccess(JSONObject jsonObject) {
                        // Display a "Toast" message
                        // to announce your success
                        Toast.makeText(getApplicationContext(), "Success!", Toast.LENGTH_LONG).show();

                        // 8. For now, just log results
                        Log.d("omg android", jsonObject.toString());
                    }

                    @Override // THIS METHOD DOES NOT OVERRIDE METHOD FROM ITS SUPERCLASS ??
                    public void onFailure(int statusCode, Throwable throwable, JSONObject error) {
                        // Display a "Toast" message
                        // to announce the failure
                        Toast.makeText(getApplicationContext(), "Error: " + statusCode + " " + throwable.getMessage(), Toast.LENGTH_LONG).show();

                        // Log error message
                        // to help solve any problems
                        Log.e("omg android", statusCode + " " + throwable.getMessage());
                    }
                });
    }
} // end class

(For what it’s worth, I’m following this tutorial).

Thanks for any thoughts!

New capacity = 1600
Vehicle Info:
capacity = 1600cc
make = Mazda
Cannot change capacity of a car
Vehicle Info:
capacity = 1200cc
make = Holden
type = sedan
model = Barina

class Vehicle {  // base class

   public void setCapacity(int setCapacity) {
     this.capacity = setCapacity;
      System.out.println("New Capacity = " + setCapacity);
   }

   int capacity;
   String make;

   Vehicle(int theCapacity, String theMake) {
      capacity = theCapacity;
      make = theMake;
   }

   void print() {
      System.out.println("Vehicle Info:");
      System.out.println("  capacity = " + capacity + "cc" );
      System.out.println("  make = " + make );
   }
}

class Car extends Vehicle {
   public String type;
   public String model;

   public Car(int theCapacity, String theMake, String theType, String theModel) {
      super(theCapacity, theMake);
      type = theType;
      model = theModel;
   }

   @Override
   public void print() {
      super.print();
      System.out.println("  type = " + type);
      System.out.println("  model = " + model);

   }

     @Override
     public void setCapacity() {
       super.print();
       System.out.println("Cannot change capacity of a car");
     }       
 }

class Task3 {

   public static void main (String[]args){
      Car car1 = new Car (1200,"Holden","sedan","Barina" );
      Vehicle v1 = new Vehicle (1500,"Mazda");
      v1.setCapacity(1600);
      v1.print();
      car1.setCapacity(1600);
      car1.print();
   }
}

3 ответа

Лучший ответ

@Override
public void setCapacity(   int capacity   ) { --> **adding this argument here will fix the issue.**
    super.print();
    System.out.println("Cannot change capacity of a car");
}

public void setCapacity(int setCapacity) {
    this.capacity = setCapacity;
    System.out.println("New Capacity = " + setCapacity);
}

public void setCapacity() { //... }

public void setCapacity(int setCapacity) { // ... }

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Я создаю макетную базу данных сотрудников с использованием наследования и полиморфизма. При попытке переопределить методы суперкласса я столкнулся с следующими ошибками.

HourlyEmployee is not abstract and does not override abstract method resetWeek() in Employee
public class HourlyEmployee extends Employee
   ^
HourlyEmployee.java:43: error: method does not override or implement a method from a supertype
@Override
^
HourlyEmployee.java:54: error: method does not override or implement a method from a supertype
@Override
^
HourlyEmployee.java:60: error: method does not override or implement a method from a supertype
@Override
^
HourlyEmployee.java:66: error: method does not override or implement a method from a supertype
@Override

Вот мой подкласс класса Employee и HourlyEmployee.

public abstract class Employee
{
protected String firstName;
protected String lastName;
protected char middleInitial;
protected boolean fulltime;
private char gender;
private int employeeNum;

public Employee (String fn, String ln, char m, char g, int empNum, boolean ft)
{
    firstName = fn;
    lastName = ln;
    middleInitial = m;
    gender = g;
    employeeNum = empNum;
    fulltime = ft;
}

public int getEmployeeNumber()
{
    return employeeNum;
}

public void setEmployeeNumber(int empNum)
{
    while (empNum <= 10000 && empNum >= 99999)
    {
        System.out.print ("Invalid input, please try again: ");
    }

    if (empNum >= 10000 && empNum <= 99999)
    {
        employeeNum = empNum;
    }
}

public String getFirstName()
{
    return firstName;
}

public String getLastName()
{
    return lastName;
}

public char checkGender(char g)
{
    if (g != 'M' || g != 'F')
    {
        g = 'F';
    }
    return g;
}

public char getGender()
{
    return gender;
}


@Override
public boolean equals(Object e2)
{
    if (this.employeeNum == ((Employee)e2).employeeNum)
    {
        return true;
    }
    else
    {
        return false;
    }
}

@Override
public String toString()
{
    return employeeNum + "n" + lastName + ", " + firstName + "n" + "Gender:" + gender + "n" + "Status:" + fulltime + "n";
}

public abstract double caclulateWeeklyPay();

public abstract void annualRaise();

public abstract double holidayBonus();

public abstract void resetWeek();
}

Вот подкласс HourlyEmployee

public class HourlyEmployee extends Employee
{
private double wage;
private double hoursWorked;
private double additionalHours;

public HourlyEmployee(String fn, String ln, char m, char g, int empNum, boolean ft, double w, double h, double ahours)
{
    super (fn, ln, m, g, empNum, ft);
    wage = w;
    hoursWorked = h;
    hoursWorked = 0.0;
    additionalHours = ahours;
}

@Override
public String toString()
{
    return this.getEmployeeNumber() + "n" + lastName + ", " + firstName + middleInitial + "n" + "Gender: "
     + this.getGender() + "n" + "Status: " + fulltime + "n" + "Wage: " + wage + "n" + "Hours Worked: " + hoursWorked + "n";
}

   //@Override    
public double calculateWeeklyPay(double w, double h)
{
    if (h > 40)
    {
        w = w * 2;
    }

    return w * h;        
}

//@Override
public double annualRaise(double w)
{
    return (w * .05) + w;
}

//@Override
public double holidayBonus(double w)
{
    return w * 40;
}

//@Override
public double resetWeek(double h)
{
    h = 0.0;
    return h;
}

public double plusHoursWorked(double h, double ahours)
{
    while (h <= 0)
    {
        System.out.println("Invalid value entered, please try again");
    }

    h += ahours;

    return h;
}


}