Music Plays and Stops with messages on ImageButtons' Clicks - android-mediaplayer

Question

Trying to code a simple programme. Four ImageButtons, any once clicked, a particular music plays with a message display; again any button clicked, the music stopped along with a message display again. The problem is that the first click to start and second click to stop performs perfectly; the problem arises when I press any button, this message displays: “Unfortunately the programme has stopped” or something like that and the program crashes.
package com.example.appliedexperimentz;
import android.app.Activity;
import android.graphics.drawable.AnimationDrawable;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends Activity {
private MediaPlayer mp;
ImageView iv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mp = new MediaPlayer();
iv = (ImageView) findViewById(R.id.spaceForAnimation);
iv.setBackgroundResource(R.drawable.animestore);
}
public void imageButton1(View v) {
if(mp.isPlaying()){
mp.release();
Toast.makeText(MainActivity.this, "Music Stopped!", Toast.LENGTH_LONG).show();
}else{
mp = MediaPlayer.create(this, R.raw.firstmusik);
mp.start();
Toast.makeText(MainActivity.this, "First Music!", Toast.LENGTH_LONG).show();
}
}
public void imageButton2(View v) {
if(mp.isPlaying()){
mp.release();
Toast.makeText(MainActivity.this, "Music Stopped!", Toast.LENGTH_LONG).show();
}else{
mp = MediaPlayer.create(this, R.raw.secondmusik);
mp.start();
Toast.makeText(MainActivity.this, "Second Music!", Toast.LENGTH_LONG).show();
}
}
public void imageButton3(View v) {
if(mp.isPlaying()){
mp.release();
Toast.makeText(MainActivity.this, "Music Stopped!", Toast.LENGTH_LONG).show();
}else{
mp = MediaPlayer.create(this, R.raw.thirdmusik);
mp.start();
Toast.makeText(MainActivity.this, "Third Music!", Toast.LENGTH_LONG).show();
}
}
public void imageButton4(View v) {
if(mp.isPlaying()){
mp.release();
Toast.makeText(MainActivity.this, "Music Stopped!", Toast.LENGTH_LONG).show();
}else{
mp = MediaPlayer.create(this, R.raw.fourthmusik);
mp.start();
Toast.makeText(MainActivity.this, "Fourth Music!", Toast.LENGTH_LONG).show();
}
}
#Override
public void onDestroy() {
mp.release();
}
}
Here go the Logcat errors:
11-14 23:23:31.943: E/AndroidRuntime(659): FATAL EXCEPTION: main
11-14 23:23:31.943: E/AndroidRuntime(659): java.lang.IllegalStateException: Could not execute method of the activity
11-14 23:23:31.943: E/AndroidRuntime(659): at android.view.View$1.onClick(View.java:3044)
11-14 23:23:31.943: E/AndroidRuntime(659): at android.view.View.performClick(View.java:3511)
11-14 23:23:31.943: E/AndroidRuntime(659): at android.view.View$PerformClick.run(View.java:14105)
11-14 23:23:31.943: E/AndroidRuntime(659): at android.os.Handler.handleCallback(Handler.java:605)
11-14 23:23:31.943: E/AndroidRuntime(659): at android.os.Handler.dispatchMessage(Handler.java:92)
11-14 23:23:31.943: E/AndroidRuntime(659): at android.os.Looper.loop(Looper.java:137)
11-14 23:23:31.943: E/AndroidRuntime(659): at android.app.ActivityThread.main(ActivityThread.java:4424)
11-14 23:23:31.943: E/AndroidRuntime(659): at java.lang.reflect.Method.invokeNative(Native Method)
11-14 23:23:31.943: E/AndroidRuntime(659): at java.lang.reflect.Method.invoke(Method.java:511)
11-14 23:23:31.943: E/AndroidRuntime(659): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
11-14 23:23:31.943: E/AndroidRuntime(659): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
11-14 23:23:31.943: E/AndroidRuntime(659): at dalvik.system.NativeStart.main(Native Method)
11-14 23:23:31.943: E/AndroidRuntime(659): Caused by: java.lang.reflect.InvocationTargetException
11-14 23:23:31.943: E/AndroidRuntime(659): at java.lang.reflect.Method.invokeNative(Native Method)
11-14 23:23:31.943: E/AndroidRuntime(659): at java.lang.reflect.Method.invoke(Method.java:511)
11-14 23:23:31.943: E/AndroidRuntime(659): at android.view.View$1.onClick(View.java:3039)
11-14 23:23:31.943: E/AndroidRuntime(659): ... 11 more
11-14 23:23:31.943: E/AndroidRuntime(659): Caused by: java.lang.IllegalStateException
11-14 23:23:31.943: E/AndroidRuntime(659): at android.media.MediaPlayer.isPlaying(Native Method)
11-14 23:23:31.943: E/AndroidRuntime(659): at com.example.appliedexperimentz.MainActivity.imageButton3(MainActivity.java:59)
11-14 23:23:31.943: E/AndroidRuntime(659): ... 14 more

Answer 1

Change your button click function as follows
public void releasePlayer() {
mp.release();
mp = null;
}
public void imageButton1(View v) {
if (mp != null && mp.isPlaying()) {
releasePlayer();
Toast.makeText(MainActivity.this, "Music Stopped!",
Toast.LENGTH_LONG).show();
} else {
mp = MediaPlayer.create(this, R.raw.muzika);
mp.start();
Toast.makeText(MainActivity.this, "First Music!", Toast.LENGTH_LONG)
.show();
}
}
Do the above changes to all the button click events. Hope this helps :)