LibGDX -> Exception in LWJGL App - cannot be cast to

Question

I hope you can help me and I hope I did not overlook any relevant answers.

So I get this Exception when I try and run my DesktopLauncher.java class.

    Executing: gradle run

Configuration on demand is an incubating feature.
warning: [options] bootstrap class path not set in conjunction with -source 1.6
1 warning
:core:compileJava
:core:processResources UP-TO-DATE
:core:classes
:core:jar
warning: [options] bootstrap class path not set in conjunction with -source 1.6
1 warning
:desktop:compileJava
:desktop:processResources UP-TO-DATE
:desktop:classes
Exception in thread "LWJGL Application" java.lang.ClassCastException: com.bluemoon.game.MainGame cannot be cast to com.badlogic.gdx.InputProcessor
    at com.bluemoon.game.MainGame.create(MainGame.java:30)
    at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:136)
    at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:114)
:desktop:run

BUILD SUCCESSFUL

Total time: 4.267 secs

I just copied the my code from this tutorial.

This is my MainGame.java from the core files

package com.bluemoon.game;

import com.badlogic.gdx.ApplicationAdapter;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.InputProcessor;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.maps.tiled.TiledMap;
import com.badlogic.gdx.maps.tiled.TiledMapRenderer;
import com.badlogic.gdx.maps.tiled.TmxMapLoader;
import com.badlogic.gdx.maps.tiled.renderers.OrthogonalTiledMapRenderer;

public class MainGame extends ApplicationAdapter {
 Texture img;
 TiledMap tiledMap;
OrthographicCamera camera;
TiledMapRenderer tiledMapRenderer;

@Override
public void create () {
    float w = Gdx.graphics.getWidth();
    float h = Gdx.graphics.getHeight();

    camera = new OrthographicCamera();
    camera.setToOrtho(false,w,h);
    camera.update();
    tiledMap = new TmxMapLoader().load("basic_map.tmx");
    tiledMapRenderer = new OrthogonalTiledMapRenderer(tiledMap);
    Gdx.input.setInputProcessor((InputProcessor) this);
}

@Override
public void render () {
    Gdx.gl.glClearColor(1, 0, 0, 1);
    Gdx.gl.glBlendFunc(GL20.GL_SRC_ALPHA, GL20.GL_ONE_MINUS_SRC_ALPHA);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
    camera.update();
    tiledMapRenderer.setView(camera);
    tiledMapRenderer.render();
 }
}

And this is my DesktopLauncher.java

package com.bluemoon.game.desktop;

import com.badlogic.gdx.backends.lwjgl.LwjglApplication;
import com.badlogic.gdx.backends.lwjgl.LwjglApplicationConfiguration;
import com.bluemoon.game.MainGame;

public class DesktopLauncher {
  public static void main (String[] arg) {
    LwjglApplicationConfiguration cfg = new LwjglApplicationConfiguration();

            cfg.fullscreen = true;
            cfg.resizable = false;

    new LwjglApplication(new MainGame(), cfg);
}

}

When I run the DesktopLauncher.java, the program is built, then the screen turns black (probably because it's going into full screen mode). After about 1-2 seconds the program crashes.

I'm using gradle a packet management system, if that's important.

Answer 1

It is because MainGame class doesn't implement InputProcessor class. It should be:

public class MainGame extends ApplicationAdapter implements InputProcessor {

Of course, you will have to implement all methods from InputProcessor.