Android How to - Read Database backed content provider and fill ListView

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The following code shows how to Read Database backed content provider and fill ListView.

Example

Register provider in manifest file

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.java2s.myapplication3.app" >
    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="18" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="java2s.com"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.java2s.myapplication3.app.MainActivity"
            android:label="java2s.com"
            >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <provider android:name=".MyProvider"
        android:authorities="com.examples.sharedb.friendprovider">
    </provider>

    </application>

</manifest>

Layout xml file

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
</LinearLayout>

Main activity Java file

package com.java2s.myapplication3.app;
// w w  w  .j  a  v  a  2  s  . co  m
import android.app.Activity;
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.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.Toast;

public class MainActivity extends Activity implements
        LoaderManager.LoaderCallbacks<Cursor>, AdapterView.OnItemClickListener {
    private static final int LOADER_LIST = 100;
    SimpleCursorAdapter mAdapter;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
       // getSupportLoaderManager().initLoader(LOADER_LIST, null, this);

        mAdapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_1, null,
                new String[]{MyProvider.Columns.FIRST},
                new int[]{android.R.id.text1}, 0);

        ListView list = new ListView(this);
        list.setOnItemClickListener(this);
        list.setAdapter(mAdapter);

        setContentView(list);
    }

    @Override
    public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
        Cursor c = mAdapter.getCursor();
        c.moveToPosition(position);

        Uri uri = Uri.withAppendedPath(MyProvider.CONTENT_URI, c.getString(0));
        String[] projection = new String[]{MyProvider.Columns.FIRST,
                MyProvider.Columns.LAST,
                MyProvider.Columns.PHONE};
        //Get the full record
        Cursor cursor = getContentResolver().query(uri, projection, null, null, null);
        cursor.moveToFirst();

        String message = String.format("%s %s, %s", cursor.getString(0), cursor.getString(1), cursor.getString(2));
        Toast.makeText(this, message, Toast.LENGTH_SHORT).show();
        cursor.close();
    }

    @Override
    public Loader<Cursor> onCreateLoader(int id, Bundle args) {
        String[] projection = new String[]{MyProvider.Columns._ID,
                MyProvider.Columns.FIRST};
        return new CursorLoader(this, MyProvider.CONTENT_URI,
                projection, null, null, null);
    }

    @Override
    public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
        mAdapter.swapCursor(data);
    }

    @Override
    public void onLoaderReset(Loader<Cursor> loader) {
        mAdapter.swapCursor(null);
    }
}

Content provider file

package com.java2s.myapplication3.app;
import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
/*from w w w  . j  a v  a2 s. com*/
import android.content.ContentProvider;
import android.content.ContentValues;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;

public class MyProvider extends ContentProvider {

    public static final Uri CONTENT_URI = Uri.parse("content://com.examples.sharedb.friendprovider/friends");
    
    public static final class Columns {
        public static final String _ID = "_id";
        public static final String FIRST = "firstName";
        public static final String LAST = "lastName";
        public static final String PHONE = "phoneNumber";
    }
    
    /* Uri Matching */
    private static final int FRIEND = 1;
    private static final int FRIEND_ID = 2;
    
    private static final UriMatcher matcher = new UriMatcher(UriMatcher.NO_MATCH);
    static {
        matcher.addURI(CONTENT_URI.getAuthority(), "friends", FRIEND);
        matcher.addURI(CONTENT_URI.getAuthority(), "friends/#", FRIEND_ID);
    }
    
    SQLiteDatabase db;
    
    @Override
    public int delete(Uri uri, String selection, String[] selectionArgs) {
        int result = matcher.match(uri);
        switch(result) {
        case FRIEND:
            return db.delete(ShareDbHelper.TABLE_NAME, selection, selectionArgs);
        case FRIEND_ID:
            return db.delete(ShareDbHelper.TABLE_NAME, "_ID = ?", new String[]{uri.getLastPathSegment()});
        default:
            return 0;
        }
    }

    @Override
    public String getType(Uri uri) {
        return null;
    }

    @Override
    public Uri insert(Uri uri, ContentValues values) {
        long id = db.insert(ShareDbHelper.TABLE_NAME, null, values);
        if(id >= 0) {
            return Uri.withAppendedPath(uri, String.valueOf(id));
        } else {
            return null;
        }
    }

    @Override
    public boolean onCreate() {
        ShareDbHelper helper = new ShareDbHelper(getContext());
        db = helper.getWritableDatabase();
        return true;
    }

    @Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
        int result = matcher.match(uri);
        switch(result) {
        case FRIEND:
            return db.query(ShareDbHelper.TABLE_NAME, projection, selection, selectionArgs, null, null, sortOrder);
        case FRIEND_ID:
            return db.query(ShareDbHelper.TABLE_NAME, projection, "_ID = ?", new String[]{uri.getLastPathSegment()}, null, null, sortOrder);
        default:
            return null;
        }
    }

    @Override
    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
        int result = matcher.match(uri);
        switch(result) {
        case FRIEND:
            return db.update(ShareDbHelper.TABLE_NAME, values, selection, selectionArgs);
        case FRIEND_ID:
            return db.update(ShareDbHelper.TABLE_NAME, values, "_ID = ?", new String[]{uri.getLastPathSegment()});
        default:
            return 0;
        }
    }

}
class ShareDbHelper extends SQLiteOpenHelper {

    private static final String DB_NAME = "frienddb";
    private static final int DB_VERSION = 1;
    
    public static final String TABLE_NAME = "friends";
    public static final String COL_FIRST = "firstName";
    public static final String COL_LAST = "lastName";
    public static final String COL_PHONE = "phoneNumber";
    
    private static final String STRING_CREATE =
        "CREATE TABLE "+TABLE_NAME+" (_id INTEGER PRIMARY KEY AUTOINCREMENT, "
        +COL_FIRST+" TEXT, "+COL_LAST+" TEXT, "+COL_PHONE+" TEXT);";

    public ShareDbHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
    }
    
    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(STRING_CREATE);
        
        ContentValues cv = new ContentValues(3);
        cv.put(COL_FIRST, "John");
        cv.put(COL_LAST, "Doe");
        cv.put(COL_PHONE, "8885551234");
        db.insert(TABLE_NAME, null, cv);
        cv = new ContentValues(3);
        cv.put(COL_FIRST, "Jane");
        cv.put(COL_LAST, "Doe");
        cv.put(COL_PHONE, "8885552345");
        db.insert(TABLE_NAME, null, cv);
        cv = new ContentValues(3);
        cv.put(COL_FIRST, "Jill");
        cv.put(COL_LAST, "Doe");
        cv.put(COL_PHONE, "8885553456");
        db.insert(TABLE_NAME, null, cv);

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS "+TABLE_NAME);
        onCreate(db);
    }
}

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