android NoClassDefFound error

Question

I'm new to coding in android and I ran into a problem today. I was able to run this a couple of hours ago but suddenly it just started giving me a NoClassDefFound error. Please help me find out why it suddenly started giving me errors.

Logcat:

11-16 22:44:34.546: E/AndroidRuntime(31850): FATAL EXCEPTION: main
11-16 22:44:34.546: E/AndroidRuntime(31850): Process: com.Blocks.blocks, PID: 31850
11-16 22:44:34.546: E/AndroidRuntime(31850): java.lang.NoClassDefFoundError: com.Blocks.blocks.Play
11-16 22:44:34.546: E/AndroidRuntime(31850):    at com.Blocks.blocks.MainActivity$1.onClick(MainActivity.java:35)
11-16 22:44:34.546: E/AndroidRuntime(31850):    at android.view.View.performClick(View.java:4445)
11-16 22:44:34.546: E/AndroidRuntime(31850):    at android.view.View$PerformClick.run(View.java:18446)
11-16 22:44:34.546: E/AndroidRuntime(31850):    at android.os.Handler.handleCallback(Handler.java:733)
11-16 22:44:34.546: E/AndroidRuntime(31850):    at android.os.Handler.dispatchMessage(Handler.java:95)
11-16 22:44:34.546: E/AndroidRuntime(31850):    at android.os.Looper.loop(Looper.java:136)
11-16 22:44:34.546: E/AndroidRuntime(31850):    at android.app.ActivityThread.main(ActivityThread.java:5146)
11-16 22:44:34.546: E/AndroidRuntime(31850):    at java.lang.reflect.Method.invokeNative(Native Method)
11-16 22:44:34.546: E/AndroidRuntime(31850):    at java.lang.reflect.Method.invoke(Method.java:515)
11-16 22:44:34.546: E/AndroidRuntime(31850):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:796)
11-16 22:44:34.546: E/AndroidRuntime(31850):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:612)
11-16 22:44:34.546: E/AndroidRuntime(31850):    at dalvik.system.NativeStart.main(Native Method)

and here is my MainActivity.java (All imports are included)

public class MainActivity extends Activity {

    Button play,Exits,AboutMe;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        AdView adView = (AdView) this.findViewById(R.id.adView);
        AdRequest adRequest = new AdRequest.Builder().addTestDevice(AdRequest.DEVICE_ID_EMULATOR).addTestDevice("12A7F007F53439A00E30C06216544A0B").build();
        adView.loadAd(adRequest);
        play=(Button)findViewById(R.id.Play);
        Exits=(Button)findViewById(R.id.Exit);
        AboutMe=(Button)findViewById(R.id.AboutMe);
        final Context context = this;

        play.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent intents=new Intent(context,Play.class);
                startActivity(intents);
            }
        });
        Exits.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                finish();
                System.exit(0);
            }
        });
        AboutMe.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent i=new Intent(context,AboutMe.class);
                startActivity(i);
            }
        });
    }

Line 35 is this:

Intent intents=new Intent(MainActivity.this,Play.class);

Manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.Blocks.blocks"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <uses-sdk
        android:minSdkVersion="9"
        android:targetSdkVersion="21"
    />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/Theme.AppCompat" >
        <meta-data android:name="com.google.android.gms.version"
        android:value="@integer/google_play_services_version" />
        <activity
            android:screenOrientation="portrait"
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:screenOrientation="portrait"
            android:name=".AboutMe"
            android:label="@string/AboutT" >
        </activity>
        <activity
            android:screenOrientation="landscape"
            android:name=".Play"
            android:theme="@android:style/Theme.NoTitleBar"
            android:label="@string/Play" >
        </activity>
        <activity
        android:name="com.google.android.gms.ads.AdActivity"
        android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize" />
    </application>

</manifest>

I have the same problem with you and I see the same pattern that you and I have. The cause seems to be screenOrientation, I know because I hit on the NoClassDefFound error after I force my screenOrientation to landscape and I haven’t found any solution yet.. — Jeff, Feb 04 '20 at 16:55

Thirumoorthy · Answer 1 · 2014-11-17T04:29:29.857

1

Clean Project after try it working fine.

edited Nov 17 '14 at 04:29

answered Nov 17 '14 at 04:20

Thirumoorthy

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You mean clean project? If you mean clean project, I have already done that and it does not work. – Andrew Chan Nov 17 '14 at 04:26
1

i face to same problem my android studio project. clean project after working fine my side. – Thirumoorthy Nov 17 '14 at 04:29
Please refer this link very usefull http://stackoverflow.com/questions/9833607/android-eclipse-noclassdeffounderror-for-external-jar-files – Thirumoorthy Nov 17 '14 at 04:39

score 0 · Answer 2 · answered Nov 17 '14 at 03:59

0

You can use:

Intent i=new Intent(MainActivity.this,AboutMe.class);

instead Of

Intent i=new Intent(context,AboutMe.class);

answered Nov 17 '14 at 03:59

Bhoomika Brahmbhatt

7,404
3
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Thanks for the quick reply, but it gives me the same error ): – Andrew Chan Nov 17 '14 at 04:05

Blaze Tama · Answer 3 · 2014-11-17T09:01:52.087

0

Change it to :

Intent intents=new Intent(MainActivity.this, Play.class);

UPDATE

It seems because you have 2 Play : One is an instance of Button and one is Activity. Change the instance of button to play (lowercase p) and this code should work.

edited Nov 17 '14 at 09:01

answered Nov 17 '14 at 03:59

Blaze Tama

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I've tried that but it gave me the same error message as before. – Andrew Chan Nov 17 '14 at 04:11

score 0 · Answer 4 · answered Nov 17 '14 at 03:59

0

Activity context available in activity methods only,so instead of setting context in activity class set it in onCreate method as

context = this;

and declare in your activity as Context context; instead of final Context context = this; i.e. rewrite your code as

 Context context;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        context = this;  // add here

or change

Intent intents=new Intent(context,Play.class);

to

Intent intents=new Intent(MainActivity.this,Play.class);

answered Nov 17 '14 at 03:59

Giru Bhai

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I've done both of those, the first one forces me to change it to final or else context does not work. The second one gives me same error code as before. Thanks for replying so fast though. – Andrew Chan Nov 17 '14 at 04:08
@AndrewChan then change `Context context;` to `final Context context;` and clear your project and retry.And also post manifest file. – Giru Bhai Nov 17 '14 at 04:10
I've done that as well haha. Crashes and gives me the error again. – Andrew Chan Nov 17 '14 at 04:13

score 0 · Answer 5 · answered Nov 17 '14 at 04:11

0

Play is a variable of type Button in your code above. Do you have an activity named Play defined in Play.class somewhere? If so, the Play variable is interfering with seeing it. Usually, Java coding styles says that class name start with capital letter and variable names start with a lower case letter. Play.class looks like a static reference, but it is really just a regular reference to a Button.

My guess is you mention to reference a different activity. If you have Play.class with a Play Activity, rename Play to play (change all of references except the problem line)

answered Nov 17 '14 at 04:11

iagreen

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Do you have a class called Play.java somewhere? – iagreen Nov 17 '14 at 04:17
Yes, I can post it. However I will warn you that it is EXTREMELY ugly...by ugly I mean that I got very lazy and put all my code into that one file haha. – Andrew Chan Nov 17 '14 at 04:20

score 0 · Answer 6 · answered Nov 17 '14 at 04:28

0

I had that issue few times, it can easily be removed by cleaning the project and than reinstalling it, what Blaze Tama showed is quite preferable way of writing intents to change activity if you choose not to write getApplicationContext();

answered Nov 17 '14 at 04:28

Pankaj Nimgade

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How exactly do I reinstall the project? And yeah, I could see that way being better. – Andrew Chan Nov 17 '14 at 04:30
well ctrl+F11 does the same thing, Did cleaning the project help you with your issues? – Pankaj Nimgade Nov 17 '14 at 04:39
did you make any changes to Play activity in anyway that you see could give you an error? – Pankaj Nimgade Nov 17 '14 at 04:44
Not that I recall. I didn't touch it after I published my app on the market. It worked perfectly at the time. – Andrew Chan Nov 17 '14 at 04:45
well did you add AddMob in you app and it stooped working, is that the case? – Pankaj Nimgade Nov 17 '14 at 04:48
Admob was included in my app that was published and it functioned correctly at the time. – Andrew Chan Nov 17 '14 at 04:49
kindly forward your link to your app, I will see what I can do? – Pankaj Nimgade Nov 17 '14 at 04:50
[link]https://play.google.com/store/apps/details?id=com.Blocks.blocks&hl=en[/link] It's my first app so it's not much :) but thanks for taking your time to figure this out for me. – Andrew Chan Nov 17 '14 at 04:52
don't worry, You did well for your first app, keep it up, I will get back to you with possible solution if I could find a one – Pankaj Nimgade Nov 17 '14 at 04:54

android NoClassDefFound error

6 Answers6