Class not found exception in Android code

Question

This is my code:

package com.example.testcode;
import android.app.ListFragment;
import android.app.LoaderManager;
import android.content.CursorLoader;
import android.content.Loader;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.support.v4.widget.SimpleCursorAdapter;
import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;
import android.widget.SearchView;
import android.widget.SearchView.OnQueryTextListener;
public class TestAndActivity extends ListFragment implements OnQueryTextListener,
 LoaderManager.LoaderCallbacks<Cursor> {
 // This is the Adapter being used to display the list's data.
 SimpleCursorAdapter mAdapter;
 // If non-null, this is the current filter the user has provided.
 String mCurFilter;
 @Override
 public void onActivityCreated(Bundle savedInstanceState) {
 super .onActivityCreated(savedInstanceState);
 // Give some text to display if there is no data. In a real
 // application this would come from a resource.
 setEmptyText("No phone numbers");
 // We have a menu item to show in action bar.
 setHasOptionsMenu(true);
 // Create an empty adapter we will use to display the loaded data.
 mAdapter = new SimpleCursorAdapter(getActivity(),
 android.R.layout.simple_list_item_2, null,
 new String[] { ContactsContract.Contacts.DISPLAY_NAME, ContactsContract.Contacts.CONTACT_STATUS },
 new int[] { android.R.id.text1, android.R.id.text2 }, 0);
 setListAdapter(mAdapter);
 // Start out with a progress indicator.
 setListShown(false);
 // Prepare the loader. Either re-connect with an existing one,
 // or start a new one.
 getLoaderManager().initLoader(0, null, this);
 }
 @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
 // Inflate the layout for this fragment 
 final View contentView = inflater.inflate(R.layout.fragment_layout, container, false); return contentView; }
 @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
 // Place an action bar item for searching.
 MenuItem item = menu.add("Search");
 //item.setIcon(android.R.drawable.ic_menu_search);
 item.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
 SearchView sv = new SearchView(getActivity());
 sv.setOnQueryTextListener(this);
 item.setActionView(sv);
 }
 public boolean onQueryTextChange(String newText) {
 // Called when the action bar search text has changed. Update
 // the search filter, and restart the loader to do a new query
 // with this filter.
 mCurFilter = !TextUtils.isEmpty(newText) ? newText : null;
 getLoaderManager().restartLoader(0, null, this);
 return true;
 }
 @Override public boolean onQueryTextSubmit(String query) {
 // Don't care about this.
 return true;
 }
 @Override public void onListItemClick(ListView l, View v, int position, long id) {
 // Insert desired behavior here.
 }
 // These are the Contacts rows that we will retrieve.
 static final String[] CONTACTS_SUMMARY_PROJECTION = new String[] {
 ContactsContract.Contacts._ID,
 ContactsContract.Contacts.DISPLAY_NAME,
 ContactsContract.Contacts.CONTACT_STATUS,
 ContactsContract.Contacts.CONTACT_PRESENCE,
 ContactsContract.Contacts.PHOTO_ID,
 ContactsContract.Contacts.LOOKUP_KEY,
 };
 public Loader<Cursor> onCreateLoader(int id, Bundle args) {
 // This is called when a new Loader needs to be created. This
 // sample only has one Loader, so we don't care about the ID.
 // First, pick the base URI to use depending on whether we are
 // currently filtering.
 Uri baseUri;
 if (mCurFilter != null) {
 baseUri = Uri.withAppendedPath(ContactsContract.Contacts.CONTENT_FILTER_URI,
 Uri.encode(mCurFilter));
 } else {
 baseUri = ContactsContract.Contacts.CONTENT_URI;
 }
 // Now create and return a CursorLoader that will take care of
 // creating a Cursor for the data being displayed.
 String select = "((" + ContactsContract.Contacts.DISPLAY_NAME + " NOTNULL) AND ("
 + ContactsContract.Contacts.HAS_PHONE_NUMBER + "=1) AND ("
 + ContactsContract.Contacts.DISPLAY_NAME + " != '' ))";
 return new CursorLoader(getActivity(), baseUri,
 CONTACTS_SUMMARY_PROJECTION, select, null,
 ContactsContract.Contacts.DISPLAY_NAME + " COLLATE LOCALIZED ASC");
 }
 public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
 // Swap the new cursor in. (The framework will take care of closing the
 // old cursor once we return.)
 mAdapter.swapCursor(data);
 // The list should now be shown.
 if (isResumed()) {
 setListShown(true);
 } else {
 setListShownNoAnimation(true);
 }
 }
 public void onLoaderReset(Loader<Cursor> loader) {
 // This is called when the last Cursor provided to onLoadFinished()
 // above is about to be closed. We need to make sure we are no
 // longer using it.
 mAdapter.swapCursor(null);
 }
}
**strong text**

This is my layout:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="horizontal"
 android:layout_width="match_parent"
 android:layout_height="match_parent">
 <fragment class="com.example.testcode.TestAndActivity"
 android:id="@+id/titles" android:layout_weight="1"
 android:layout_width="0px"
 android:layout_height="match_parent" />
 <FrameLayout android:id="@+id/details" android:layout_weight="1"
 android:layout_width="0px"
 android:layout_height="match_parent" />
</LinearLayout>

This is my manifest:

**<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
 package="com.example.testcode"
 android:versionCode="1"
 android:versionName="1.0" >
 <uses-permission android:name="android.permission.READ_CONTACTS"/>
 <uses-sdk android:minSdkVersion="15" />
 <application
 android:icon="@drawable/ic_launcher"
 android:label="@string/app_name" >
 <activity android:label="@string/app_name"
 android:name="android.app.TestAndActivity">
 <intent-filter>
 <action android:name="android.intent.action.MAIN" />
 <category android:name="android.intent.category.LAUNCHER" />
 </intent-filter>
 </activity>
 </application>
</manifest>**

The error I get is this:

 01-24 22:50:49.751: E/AndroidRuntime(1416): Caused by: java.lang.ClassNotFoundException: android.app.TestAndActivity

I am using fragments and loaders for the first time. Though, code has no errors, I believe I got it wrong in both the manifest and layout.

Can anyone tell me where I went wrong? **

Edit:

**

If I change android.app.TestAndActivity to .TestAndActivity, I get the error can not cast TestAndActivity to android.app. 

• Lucifer: what is the JDK version you are using ?
• Hick: I use google apis. Android 4.03.
• Shaiful: Where is your R.layout.fragment_layout
• Shaiful: First read this http://developer.android.com/reference/android/app/Fragment.html

Answer 1

You are using Fragment not the Activity and define the Fragment as Activity in manifest. Fragment should be inside an Activity. Create another Activity, put the Fragment in their and define the Activity Name in Manifest.

• Hick: Edited the question. Do check.
• Shaiful: Read this - http://developer.android.com/guide/topics/fundamentals/fragments.html

Answer 2

Activity not defined with correct package name. It should be com.example.testcode.TestAndActivity

Answer 3

change android:name="android.app.TestAndActivity" to android:name=".TestAndActivity"

your package declaration is package com.example.testcode; and your TestAndActivity is under this package then why are you using android.app in your activity declaration.

Answer 4

try this,

this is your line in AndroidmainFest.xml

<activity android:label="@string/app_name"
 android:name="android.app.TestAndActivity">

Change it according below code,

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

• Hick: Edited the question. Do check.