Unable to instantiate activity componentinfo ошибка

Today, we will learn about another runtime exception that says Unable to instantiate activity ComponentInfo.

We will explore different possible reasons that result in java.lang.RuntimeException: Unable to instantiate activity ComponentInfo. Finally, we will have a solution to eradicate it.

Resolve the java.lang.RuntimeException: Unable to instantiate activity ComponentInfo Error

Example Code for Error Demonstration (MainActivity.java file):

public class MainActivity extends Activity {

  @Override
  protected void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
  }
  //write your remaining code here
}

Example Code (AndroidManifest.xml file):

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.example.app">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.App"
        tools:targetApi="31">

        <activity
            android:name="MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>

</manifest>

When we try to run this while launching an application in the android emulator, we get the error saying java.lang.RuntimeException: Unable to instantiate activity ComponentInfo.

There are a few possible causes that we must consider to resolve this. All of them are listed below.

• Make sure that your Activity is added to the AndroidManifest.xml file. Why is it necessary?

  It is because whenever we want to make a new Activity, we must register in our AndroidManifest.xml file. Also, verify all the access modifiers.

• We also get this error when we try to view before onCreate(), which is incorrect and results in an error stating unable to instantiate activity component info error.

• Another reason for getting java.lang.RuntimeException: Unable to instantiate activity ComponentInfo is that we have added our Activity in AndroidManifest.xml, which is declared as abstract. In other words, we can say that the Activity we are trying to access is declared abstract.

• Make sure that we are not missing a preceding dot before an activity path (this thing is causing an error in the example code given above).

• We also have to face this error if we did not declare our MainActivity.java file as public. Also, check if your file is in the right package or not.

Now, we know all the possible reasons. How can we fix it?

See the following solution.

Example Code for Solution (MainActivity.java file):

public class MainActivity extends Activity {

  @Override
  protected void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
  }
  //write your remaining code here
}

Example Code (AndroidManifest.xml file):

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.example.app">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.App"
        tools:targetApi="31">

        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>

</manifest>

We have added a preceding dot before an activity path. We also confirm that our MainActivity.java file is declared as public, and we are not trying to access an Activity declared as abstract.

Be careful of all the points given as causes because those points are actual solutions if we consider them.

tns-core-modules 6.0.4 
tns-android 6.0.1  

Will emit event runOnDeviceExecuted with data { projectDir:
   'C:\Users\unite',
  deviceIdentifier: '52033ae5f42a146f',
  applicationIdentifier: 'org.nativescript.Unite',
  syncedFiles:
   [ 'C:\Users\unite\platforms\android\app\src\main\assets\app\runtime.js' ],
  isFullSync: true }
Will send the following information to Google Analytics: { type: 'googleAnalyticsData',
  category: 'CLI',
  googleAnalyticsDataType: 'event',
  action: 'Performance',
  label: 'RunController__refreshApplicationWithoutDebug',
  customDimensions: { cd2: 'Angular', cd9: 'false', cd5: 'Unknown' },
  value: 3751 }
Successfully synced application org.nativescript.Unite on device 52033ae5f42a146f.
Will emit event runOnDeviceStarted with data { projectDir:
   'C:\Users\unite',
  deviceIdentifier: '52033ae5f42a146f',
  applicationIdentifier: 'org.nativescript.Unite' }
System.err: An uncaught Exception occurred on "main" thread.
System.err: Unable to instantiate activity ComponentInfo{org.nativescript.Unite/com.tns.NativeScriptActivity}: java.lang.ClassNotFoundException: Didn't find class "com.tns.NativeScriptActivity" on path: DexPathList[[zip file "/data/app/org.nativescript.Unite-N8LvQmyn0YOtygBLHss0Mw==/base.apk"],nativeLibraryDirectories=[/data/app/org.nativescript.Unite-N8LvQmyn0YOtygBLHss0Mw==/lib/arm, /data/app/org.nativescript.Unite-N8LvQmyn0YOtygBLHss0Mw==/base.apk!/lib/armeabi-v7a, /system/lib, /system/vendor/lib]]
System.err: 
System.err: StackTrace:
System.err: java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{org.nativescript.Unite/com.tns.NativeScriptActivity}: java.lang.ClassNotFoundException: Didn't find class "com.tns.NativeScriptActivity" on path: DexPathList[[zip file "/data/app/org.nativescript.Unite-N8LvQmyn0YOtygBLHss0Mw==/base.apk"],nativeLibraryDirectories=[/data/app/org.nativescript.Unite-N8LvQmyn0YOtygBLHss0Mw==/lib/arm, /data/app/org.nativescript.Unite-N8LvQmyn0YOtygBLHss0Mw==/base.apk!/lib/armeabi-v7a, /system/lib, /system/vendor/lib]]
System.err: 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2850)
System.err: 	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3059)
System.err: 	at android.app.ActivityThread.-wrap11(Unknown Source:0)
System.err: 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1724)
System.err: 	at android.os.Handler.dispatchMessage(Handler.java:106)
System.err: 	at android.os.Looper.loop(Looper.java:164)
System.err: 	at android.app.ActivityThread.main(ActivityThread.java:7000)
System.err: 	at java.lang.reflect.Method.invoke(Native Method)
System.err: 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:441)
System.err: 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1408)
System.err: Caused by: java.lang.ClassNotFoundException: Didn't find class "com.tns.NativeScriptActivity" on path: DexPathList[[zip file "/data/app/org.nativescript.Unite-N8LvQmyn0YOtygBLHss0Mw==/base.apk"],nativeLibraryDirectories=[/data/app/org.nativescript.Unite-N8LvQmyn0YOtygBLHss0Mw==/lib/arm, /data/app/org.nativescript.Unite-N8LvQmyn0YOtygBLHss0Mw==/base.apk!/lib/armeabi-v7a, /system/lib, /system/vendor/lib]]
System.err: 	at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:125)
System.err: 	at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
System.err: 	at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
System.err: 	at android.app.Instrumentation.newActivity(Instrumentation.java:1182)
System.err: 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2840)
System.err: 	... 9 more

Answer by Pablo Benton

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Replace this

<activity
        android:name="amitechnologies.products.apps.equalizeraudioplayer.v3.view.LoaderOfAllMediaFiles"         
</activity>

with this

 <activity
        android:name=".amitechnologies.products.apps.equalizeraudioplayer.v3.view.LoaderOfAllMediaFiles"         
 </activity>

Answer by Camilla Ferguson

At the time you want to create a new activity, you must register it in your AndroidManifest.xml.,There is another method to obtain an java.lang.RuntimeException: Unable to instantiate activity Component Info exception and that is the activity that you are attempting to begin is abstract. I made this stupid mistake at one time and its very simple to overlook.,
backup a table in sql
,Further, the package string for my activity was wrong, for example

You may be attempting to find the view before onCreate() which is incorrect.

public class MainActivity extends Activity {

  ImageView mainImage = (ImageView) findViewById(R.id.imageViewMain); //incorrect

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

In my instance I forgot to include the google maps library

<application>
    ....

    <uses-library android:name="com.google.android.maps" />
</application>

Further, check that you’re not missing the former dot prior the activity path

<activity android:name=".activities.MainActivity"/>

This error can also be the ultimate sign of a dumb mistake (like when I — I imply, cough, like at the time a friend of mine who showed me their code once) where they attempt to execute code outside of a method like attempting to do this:

SQLiteDatabase db = openOrCreateDatabase("DB", MODE_PRIVATE, null); //trying to perform function where you can only set up objects, primitives, etc

@Override
public void onCreate(Bundle savedInstanceState) {
....
}

Rather than this:

SQLiteDatabase db;

@Override
public void onCreate(Bundle savedInstanceState) {
db = openOrCreateDatabase("DB", MODE_PRIVATE, null);
....
}

For me, my package string in AndroidManifest.xml was inaccurate . Ensure that the package string in this file is the similar as where your main activity is, for example

 package="com.example.app"

Further, the package string for my activity was wrong, for example

<activity android:name="com.example.app.MainActivity" android:label="@string/app_name">

In case this is the instance, you require to include an extra configuration in the webpack.config.js file. To resolve the incident include `MainActivity: ./activity’, to the entry in webpack.config.js like this:

const entry = {
    // Discover entry module from package.json
    bundle: `./${nsWebpack.getEntryModule()}`,
 
    // Vendor entry with third-party libraries
    vendor: `./vendor`,
 
    /// HERE
    MainActivity: './activity',
 
    // Entry for stylesheet with global application styles
    [mainSheet]: `./${mainSheet}`,
};

Answer by Greyson Stafford

If you add any files,it will delete all existing files related to this question-(questions only answer remains unchanged),Note** this option does not delete the question immediately,Since others contribution also matters and security reasons.Your request will be Queued.We will review the question and remove.It may take some days.,If you add any files,it will delete all existing files related to this answer-(only this answer),in my aplication i wanna to view a slide pictures as the marquee with the text view (put here with images instead of the text view ), i have this code already from the internet but at the run time i have a run time exception which is » unable to instantiate activity componentinfo»
i try to fix the problem by right click on the project and then goes to properties then at java build path do some thing ,, and then clean the project but also i still have the same problem ,, i have been restarted the emulator and eclipse but also this isn’t useful for me what must i do to run this code ??

this is my code:

            package com.example.marquee;

        import java.util.Timer;
        import java.util.TimerTask;

        import android.app.Activity;
        import android.os.Bundle;
        import android.os.Handler;
        import android.view.View;
        import android.widget.ImageView;

        public class AutoSlider extends Activity {

            public int currentimageindex=0;
            Timer timer;
            TimerTask task;
            ImageView slidingimage;

            int[] IMAGE_IDS = {R.drawable.ic_launcher, R.drawable.yt, R.drawable.yt,
                    R.drawable.s};

            @Override
            protected void onCreate(Bundle savedInstanceState) 
        {
            // TODO Auto-generated method stub
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
                final Handler mHandler = new Handler();

                // Create runnable for posting
                final Runnable mUpdateResults = new Runnable() {
                    public void run() {

                        AnimateandSlideShow();

                    }
                };

                int delay = 1000; // delay for 1 sec.

                int period = 8000; // repeat every 4 sec.

                Timer timer = new Timer();

                timer.scheduleAtFixedRate(new TimerTask() {

                public void run() {

                     mHandler.post(mUpdateResults);

                }

                }, delay, period);

            }

            public void onClick(View v) {

                finish();
                android.os.Process.killProcess(android.os.Process.myPid());
              }
               private void AnimateandSlideShow() {

                slidingimage = (ImageView)findViewById(R.id.imageView1);
                slidingimage.setImageResource(IMAGE_IDS[currentimageindex%IMAGE_IDS.length]);

                currentimageindex++;

              }}

Answer by Malaysia Bullock

I was having the same problem and your comment about starting from scratch prompted the answer – you just need to do a clean build.,If you find copyright violations, you can contact us at info-generacodice.com to request the removal of the content.,You cant cast your class Prefs to Activity,The Contents are licensed under creative commons.

Prefs.java:

   package org.example.sudoku;

    import android.os.Bundle;
    import android.preference.PreferenceFragment;
    //import android.preference.PreferenceActivity;


    public class Prefs extends PreferenceFragment {
        public void onCreate(Bundle saveInstanceState) {
            super.onCreate(saveInstanceState);
            addPreferencesFromResource(R.xml.settings); 
        }

    }

Sudoku.java:

       package org.example.sudoku;
        import android.app.Activity;
        import android.os.Bundle;

        import android.content.Intent;
        import android.view.View;
        import android.view.View.OnClickListener;

        import android.view.Menu;
        import android.view.MenuInflater;
        import android.view.MenuItem;


        public class Sudoku extends Activity implements OnClickListener{

            @Override
            public void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.main);

                // Set up click listeners for all the buttons

                View continueButton = findViewById(R.id.continue_button);
                    continueButton.setOnClickListener(this);
                View newButton = findViewById(R.id.new_button);
                    newButton.setOnClickListener(this);
                View aboutButton = findViewById(R.id.about_button);
                    aboutButton.setOnClickListener(this);
                View exitButton = findViewById(R.id.exit_button);
                    exitButton.setOnClickListener(this);
            }

            public void onClick(View v) {
                switch (v.getId())
                {
                case R.id.about_button:
                    Intent i = new Intent(this, About.class);
                    startActivity(i);
                    break;
                }
        }

            @Override
        public boolean onCreateOptionsMenu(Menu menu) {
            super.onCreateOptionsMenu(menu);
            MenuInflater inflater = getMenuInflater();
            inflater.inflate(R.menu.menu, menu);
            return true;    

        }


        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
            switch(item.getItemId()) {
            case R.id.settings:
                //startActivity(new Intent(this, Prefs.class));
                Intent intent = new Intent(this, Prefs.class);
                startActivity(intent);
                return true;
            }
            return false;


        }
        }

AndroidManifest.xml:

    <?xml version="1.0" encoding="UTF-8"?>
        <menu xmlns:android="http://schemas.android.com/apk/res/android">
            <item android:id="@+id/settings"
                android:title="@string/settings_label"
                android:alphabeticShortcut="@string/settings_shortcut" />



        </menu>

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

        <uses-sdk android:minSdkVersion="15" />

        <application
            android:icon="@drawable/ic_launcher"
            android:label="@string/app_name" >
            <activity
                android:name=".Sudoku"
                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:name=".About"
                    android:label="@string/about_title"
                    android:theme="@android:style/Theme.Dialog">

            </activity>
            <activity android:name=".Prefs"
                    android:label="@string/settings_title">

            </activity>
        </application>

    </manifest>

strings.xml:

    <?xml version="1.0" encoding="utf-8"?>
    <resources>

        <string name="hello">Hello World, Sudoku!</string>
        <string name="app_name">Sudoku Game</string>
        <string name="continue_label">Continue</string>
        <string name="new_game_label">New Game</string>
        <string name="about_label">About</string>
        <string name="exit_label">Exit</string>
        <string name="about_text">Sudoku is a logic-based number placement puzzle. Starting with a partially completed 9x9 grid so that each row, each column, and each of the 3x3 boxes(also called <i>block</i>) contains the digits 1 to 9 exactly once</string>
        <string name="about_title">About Android Sudoku</string>

        <string name="settings_label">Settings
            </string>
        <string name="settings_title">Sudoku Settings</string>
        <string name="settings_shortcut">s</string>
        <string name="music_title">Music</string>
        <string name="music_summary">Play Background Music</string>
        <string name="hints_title">Hints</string>
        <string name="hints_summary">Show hints during play</string>


        </resources>

settings.xml:

    <code>
    <?xml version="1.0" encoding="utf-8"?>
        <PreferenceScreen
        xmlns:android="http://schemas.android.com/apk/res/android">
        <PreferenceCategory
                android:title="@string/settings_title"> 
        <CheckboxPreference
            android:key="music"
            android:title="@string/music_title"
            android:summary="@string/music_summary"
            android:defaultValue="true" />
        <CheckBoxPreference
            android:key="hints"
            android:title="@string/hints_title"
            android:summary="@string/hints_summary"
            android:defaultValue="true" />
        </PreferenceCategory>
        </PreferenceScreen>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/app_name"
            android:gravity="center"
            android:layout_marginBottom="20dip"
            android:textSize="24.5sp"
             />
        <TableLayout 
            android:layout_height="wrap_content"
            android:layout_width="wrap_content"
            android:layout_gravity="center"
            android:stretchColumns="*">
            <TableRow>

                <Button 
            android:id="@+id/continue_button"
            android:text="@string/continue_label"
            />
            <Button 
            android:id="@+id/new_button"
            android:text="@string/new_game_label"
            />
            </TableRow>
            <TableRow >
            <Button 
            android:id="@+id/about_button"
            android:text="@string/about_label"
            />

            <Button 
            android:id="@+id/exit_button"
            android:text="@string/exit_label"
            />
            </TableRow>
            </TableLayout>

    </LinearLayout>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/app_name"
            android:gravity="center"
            android:layout_marginBottom="20dip"
            android:textSize="24.5sp"
             />
        <TableLayout 
            android:layout_height="wrap_content"
            android:layout_width="wrap_content"
            android:layout_gravity="center"
            android:stretchColumns="*">
            <TableRow>

                <Button 
            android:id="@+id/continue_button"
            android:text="@string/continue_label"
            />
            <Button 
            android:id="@+id/new_button"
            android:text="@string/new_game_label"
            />
            </TableRow>
            <TableRow >
            <Button 
            android:id="@+id/about_button"
            android:text="@string/about_label"
            />

            <Button 
            android:id="@+id/exit_button"
            android:text="@string/exit_label"
            />
            </TableRow>
            </TableLayout>

    </LinearLayout>

    05-18 12:37:16.781: E/AndroidRuntime(623): FATAL EXCEPTION: main
    05-18 12:37:16.781: E/AndroidRuntime(623): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{org.example.sudoku/org.example.sudoku.Prefs}: java.lang.ClassCastException: org.example.sudoku.Prefs cannot be cast to android.app.Activity
    05-18 12:37:16.781: E/AndroidRuntime(623):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1880)
    05-18 12:37:16.781: E/AndroidRuntime(623):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
    05-18 12:37:16.781: E/AndroidRuntime(623):  at android.app.ActivityThread.access$600(ActivityThread.java:123)
    05-18 12:37:16.781: E/AndroidRuntime(623):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
    05-18 12:37:16.781: E/AndroidRuntime(623):  at android.os.Handler.dispatchMessage(Handler.java:99)
    05-18 12:37:16.781: E/AndroidRuntime(623):  at android.os.Looper.loop(Looper.java:137)
    05-18 12:37:16.781: E/AndroidRuntime(623):  at android.app.ActivityThread.main(ActivityThread.java:4424)
    05-18 12:37:16.781: E/AndroidRuntime(623):  at java.lang.reflect.Method.invokeNative(Native Method)
    05-18 12:37:16.781: E/AndroidRuntime(623):  at java.lang.reflect.Method.invoke(Method.java:511)
    05-18 12:37:16.781: E/AndroidRuntime(623):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
    05-18 12:37:16.781: E/AndroidRuntime(623):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
    05-18 12:37:16.781: E/AndroidRuntime(623):  at dalvik.system.NativeStart.main(Native Method)
    05-18 12:37:16.781: E/AndroidRuntime(623): Caused by: java.lang.ClassCastException: org.example.sudoku.Prefs cannot be cast to android.app.Activity
    05-18 12:37:16.781: E/AndroidRuntime(623):  at android.app.Instrumentation.newActivity(Instrumentation.java:1023)
    05-18 12:37:16.781: E/AndroidRuntime(623):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1871)
    05-18 12:37:16.781: E/AndroidRuntime(623):  ... 11 more