java.lang.RuntimeException: Unable to instantiate activity ComponentInfo / is not accessible from class

Question

I am trying to make an app run and as soon as I select a menu item the application stops working and I get the following errors:

logcat:      03-23 19:54:11.029: E/AndroidRuntime(1316): FATAL EXCEPTION: main 03-23 19:54:11.029: E/AndroidRuntime(1316): Process: com.example.testcalnd2, PID: 1316 03-23 19:54:11.029: E/AndroidRuntime(1316): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.testcalnd2/com.example.testcalnd2.ActivityDiaryEdit}: java.lang.IllegalAccessException: class com.example.testcalnd2.ActivityDiaryEdit is not accessible from class android.app.Instrumentation 03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2236) 03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390) 03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.app.ActivityThread.access$800(ActivityThread.java:151) 03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) 03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.os.Handler.dispatchMessage(Handler.java:102) 03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.os.Looper.loop(Looper.java:135) 03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.app.ActivityThread.main(ActivityThread.java:5257) 03-23 19:54:11.029: E/AndroidRuntime(1316):     at java.lang.reflect.Method.invoke(Native Method) 03-23 19:54:11.029: E/AndroidRuntime(1316):     at java.lang.reflect.Method.invoke(Method.java:372) 03-23 19:54:11.029: E/AndroidRuntime(1316):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 03-23 19:54:11.029: E/AndroidRuntime(1316):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 03-23 19:54:11.029: E/AndroidRuntime(1316): Caused by: java.lang.IllegalAccessException: class com.example.testcalnd2.ActivityDiaryEdit is not accessible from class android.app.Instrumentation 03-23 19:54:11.029: E/AndroidRuntime(1316):     at java.lang.Class.newInstance(Class.java:1591) 03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.app.Instrumentation.newActivity(Instrumentation.java:1066) 03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2226) 03-23 19:54:11.029: E/AndroidRuntime(1316):     ... 10 more 03-23 19:54:20.399: I/Process(1316): Sending signal. PID: 1316 SIG: 9 

MainActivity class:

package com.example.testcalnd2;  import android.app.Activity; import android.app.ListActivity; import android.content.Intent; import android.database.Cursor; import android.os.Bundle; import android.support.v4.widget.SimpleCursorAdapter; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.ListView;  public class MainActivity extends ListActivity {       private static final int ACTIVITY_CREATE = 0;       private static final int ACTIVITY_EDIT = 1;        private static final int INSERT_ID = Menu.FIRST;       private static final int DELETE_ID = Menu.FIRST + 1;        private DiaryDbAdapter mDbHelper;       private Cursor mDiaryCursor;        @Override       public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.diary_list);         mDbHelper = new DiaryDbAdapter(this);         mDbHelper.open();         renderListView();        }        private void renderListView() {         mDiaryCursor = mDbHelper.getAllNotes();         startManagingCursor(mDiaryCursor);         String[] from = new String[] { DiaryDbAdapter.KEY_TITLE,             DiaryDbAdapter.KEY_CREATED };         int[] to = new int[] { R.id.text1, R.id.created };         SimpleCursorAdapter notes = new SimpleCursorAdapter(this,             R.layout.diary_now, mDiaryCursor, from, to);         setListAdapter(notes);       }        @Override       public boolean onCreateOptionsMenu(Menu menu) {         super.onCreateOptionsMenu(menu);         menu.add(0, INSERT_ID, 0, R.string.menu_insert);         menu.add(0, DELETE_ID, 0, R.string.menu_delete);        return true;      }        @Override       public boolean onMenuItemSelected(int featureId, MenuItem item) {         switch (item.getItemId()) {         case INSERT_ID:           createDiary();           return true;         case DELETE_ID:           mDbHelper.deleteDiary(getListView().getSelectedItemId());           renderListView();           return true;         }         return super.onMenuItemSelected(featureId, item);       }        private void createDiary() {         Intent i = new Intent(this, ActivityDiaryEdit.class);         startActivityForResult(i, ACTIVITY_CREATE);       }        @Override        protected void onListItemClick(ListView l, View v, int position, long id) {         super.onListItemClick(l, v, position, id);         Cursor c = mDiaryCursor;         c.moveToPosition(position);         Intent i = new Intent(this, ActivityDiaryEdit.class);         i.putExtra(DiaryDbAdapter.KEY_ROWID, id);         i.putExtra(DiaryDbAdapter.KEY_TITLE, c.getString(c             .getColumnIndexOrThrow(DiaryDbAdapter.KEY_TITLE)));         i.putExtra(DiaryDbAdapter.KEY_BODY, c.getString(c             .getColumnIndexOrThrow(DiaryDbAdapter.KEY_BODY)));         startActivityForResult(i, ACTIVITY_EDIT);       }        @Override       protected void onActivityResult(int requestCode, int resultCode,           Intent intent) {         super.onActivityResult(requestCode, resultCode, intent);         renderListView();       }     }   package com.example.testcalnd2;  import android.app.ListActivity; import android.content.Intent; import android.database.Cursor; import android.os.Bundle; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.ListView; import android.widget.SimpleCursorAdapter; 

DiaryDbAdapter:

import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.EditText;  import java.util.Calendar; import java.util.Date;  import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.util.Log;   class DiaryDbAdapter {    public static final String KEY_TITLE = "title";   public static final String KEY_BODY = "body";   public static final String KEY_ROWID = "_id";   public static final String KEY_CREATED = "created";    private static final String TAG = "DiaryDbAdapter";   private DatabaseHelper mDbHelper;   private SQLiteDatabase mDb;    private static final String DATABASE_CREATE = "create table diary (_id integer primary key autoincrement, "       + "title text not null, body text not null, created text not null);";    private static final String DATABASE_NAME = "database";   private static final String DATABASE_TABLE = "diary";   private static final int DATABASE_VERSION = 1;    private final Context mCtx;    private static class DatabaseHelper extends SQLiteOpenHelper {      DatabaseHelper(Context context) {       super(context, DATABASE_NAME, null, DATABASE_VERSION);     }      @Override     public void onCreate(SQLiteDatabase db) {       db.execSQL(DATABASE_CREATE);     }      @Override     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {       db.execSQL("DROP TABLE IF EXISTS diary");       onCreate(db);     }   }    public DiaryDbAdapter(Context ctx) {     this.mCtx = ctx;   }    public DiaryDbAdapter open() throws SQLException {     mDbHelper = new DatabaseHelper(mCtx);     mDb = mDbHelper.getWritableDatabase();     return this;   }    public void closeclose() {     mDbHelper.close();   }    public long createDiary(String title, String body) {     ContentValues initialValues = new ContentValues();     initialValues.put(KEY_TITLE, title);     initialValues.put(KEY_BODY, body);     Calendar calendar = Calendar.getInstance();     String created = calendar.get(Calendar.YEAR) + ""         + calendar.get(Calendar.MONTH) + ""         + calendar.get(Calendar.DAY_OF_MONTH) + ""         + calendar.get(Calendar.HOUR_OF_DAY) + ""         + calendar.get(Calendar.MINUTE) + "";     initialValues.put(KEY_CREATED, created);     return mDb.insert(DATABASE_TABLE, null, initialValues);   }    public boolean deleteDiary(long rowId) {      return mDb.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;   }    public Cursor getAllNotes() {      return mDb.query(DATABASE_TABLE, new String[] { KEY_ROWID, KEY_TITLE,         KEY_BODY, KEY_CREATED }, null, null, null, null, null);   }    public Cursor getDiary(long rowId) throws SQLException {      Cursor mCursor =      mDb.query(true, DATABASE_TABLE, new String[] { KEY_ROWID, KEY_TITLE,         KEY_BODY, KEY_CREATED }, KEY_ROWID + "=" + rowId, null, null,         null, null, null);     if (mCursor != null) {       mCursor.moveToFirst();     }     return mCursor;    }    public boolean updateDiary(long rowId, String title, String body) {     ContentValues args = new ContentValues();     args.put(KEY_TITLE, title);     args.put(KEY_BODY, body);     Calendar calendar = Calendar.getInstance();     String created = calendar.get(Calendar.YEAR) + ""         + calendar.get(Calendar.MONTH) + ""         + calendar.get(Calendar.DAY_OF_MONTH) + ""         + calendar.get(Calendar.HOUR_OF_DAY) + ""         + calendar.get(Calendar.MINUTE) + "";     args.put(KEY_CREATED, created);      return mDb.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;   } } 

ActivityDiaryEdit activity:

 class ActivityDiaryEdit extends Activity {    private EditText mTitleText;   private EditText mBodyText;   private Long mRowId;   private DiaryDbAdapter mDbHelper;    @Override   protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     mDbHelper = new DiaryDbAdapter(this);     mDbHelper.open();     setContentView(R.layout.diary_edit);      mTitleText = (EditText) findViewById(R.id.title);     mBodyText = (EditText) findViewById(R.id.body);      Button confirmButton = (Button) findViewById(R.id.confirm);      mRowId = null;     Bundle extras = getIntent().getExtras();     if (extras != null) {       String title = extras.getString(DiaryDbAdapter.KEY_TITLE);       String body = extras.getString(DiaryDbAdapter.KEY_BODY);       mRowId = extras.getLong(DiaryDbAdapter.KEY_ROWID);        if (title != null) {         mTitleText.setText(title);       }       if (body != null) {         mBodyText.setText(body);       }     }      confirmButton.setOnClickListener(new View.OnClickListener() {       public void onClick(View view) {         String title = mTitleText.getText().toString();         String body = mBodyText.getText().toString();         if (mRowId != null) {           mDbHelper.updateDiary(mRowId, title, body);         } else           mDbHelper.createDiary(title, body);         Intent mIntent = new Intent();         setResult(RESULT_OK, mIntent);         finish();       }      });   } } 

manifest:

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"     package="com.example.testcalnd2"     android:versionCode="1"     android:versionName="1.0" >      <uses-sdk         android:minSdkVersion="14"         android:targetSdkVersion="22" />      <application         android:allowBackup="true"         android:icon="@drawable/ic_launcher"         android:label="@string/app_name"         android:theme="@style/AppTheme" >         <activity             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:name=".DiaryDbAdapter"             android:label="@string/title_activity_diary_db_adapter" >         </activity>         <activity                 android:name="com.example.testcalnd2.ActivityDiaryEdit">  </activity>      </application>  </manifest> 

Answer 1

Make your class ActivityDiaryEdit public like this:

public class ActivityDiaryEdit extends Activity {     ... 

Hope this helps!!