Android Open Source - context-sms Favorites Db Adapter

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The source code is released under:

MIT License

Java Source Code

/*
 * Copyright (C) 2008 Google Inc.//from   w w w .j a v a 2  s  .  co  m
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 * 
 * This has been modified by Bret Black for use with the WeSay app
 */

package com.bretblack.wesay;

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;

/**
 * Simple notes database access helper class. Defines the basic CRUD operations
 * for the notepad example, and gives the ability to list all notes as well as
 * retrieve or modify a specific note.
 * 
 * This has been improved from the first version of this tutorial through the
 * addition of better error handling and also using returning a Cursor instead
 * of using a collection of inner classes (which is less scalable and not
 * recommended).
 */
public class FavoritesDbAdapter {

  public static final String KEY_TITLE = "title";
  public static final String KEY_BODY = "body";
  public static final String KEY_ROWID = "_id";
  private static final long serialVersionUID = 0L;

  private static final String TAG = "NotesDbAdapter";
  private DatabaseHelper mDbHelper;
  private SQLiteDatabase mDb;

  /**
   * Database creation sql statement
   */
  private static final String DATABASE_CREATE = "create table notes (_id integer primary key autoincrement, "
      + "title text not null, body text not null);";

  private static final String DATABASE_NAME = "data";
  private static final String DATABASE_TABLE = "notes";
  private static final int DATABASE_VERSION = 2;

  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) {
      Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
          + newVersion + ", which will destroy all old data");
      db.execSQL("DROP TABLE IF EXISTS notes");
      onCreate(db);
    }
  }

  /**
   * Constructor - takes the context to allow the database to be
   * opened/created
   * 
   * @param ctx
   *            the Context within which to work
   */
  public FavoritesDbAdapter(Context ctx) {
    this.mCtx = ctx;
  }

  /**
   * Open the notes database. If it cannot be opened, try to create a new
   * instance of the database. If it cannot be created, throw an exception to
   * signal the failure
   * 
   * @return this (self reference, allowing this to be chained in an
   *         initialization call)
   * @throws SQLException
   *             if the database could be neither opened or created
   */
  public FavoritesDbAdapter open() throws SQLException {
    mDbHelper = new DatabaseHelper(mCtx);
    mDb = mDbHelper.getWritableDatabase();
    return this;
  }

  public void close() {
    mDbHelper.close();
  }

  public void deleteTable() {
    mDb.delete(DATABASE_TABLE, null, null);
  }

  /**
   * Create a new note using the title and body provided. If the note is
   * successfully created return the new rowId for that note, otherwise return
   * a -1 to indicate failure.
   * 
   * @param title
   *            the title of the note
   * @param body
   *            the body of the note
   * @return rowId or -1 if failed
   */
  public long createNote(String title, String body) {
    ContentValues initialValues = new ContentValues();
    initialValues.put(KEY_TITLE, title);
    initialValues.put(KEY_BODY, body);

    return mDb.insert(DATABASE_TABLE, null, initialValues);
  }

  /**
   * Delete the note with the given rowId
   * 
   * @param rowId
   *            id of note to delete
   * @return true if deleted, false otherwise
   */
  public boolean deleteNote(long rowId) {

    return mDb.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
  }

  /**
   * Return a Cursor over the list of all notes in the database
   * 
   * @return Cursor over all notes
   */
  public Cursor fetchAllNotes() {

    return mDb.query(DATABASE_TABLE, new String[] { KEY_ROWID, KEY_TITLE,
        KEY_BODY }, null, null, null, null, null);
  }

  /**
   * Return a Cursor positioned at the note that matches the given rowId
   * 
   * @param rowId
   *            id of note to retrieve
   * @return Cursor positioned to matching note, if found
   * @throws SQLException
   *             if note could not be found/retrieved
   */
  public Cursor fetchNote(long rowId) throws SQLException {

    Cursor mCursor =

    mDb.query(true, DATABASE_TABLE, new String[] { KEY_ROWID, KEY_TITLE,
        KEY_BODY }, KEY_ROWID + "=" + rowId, null, null, null, null,
        null);
    if (mCursor != null) {
      mCursor.moveToFirst();
    }
    return mCursor;

  }

  /**
   * Update the note using the details provided. The note to be updated is
   * specified using the rowId, and it is altered to use the title and body
   * values passed in
   * 
   * @param rowId
   *            id of note to update
   * @param title
   *            value to set note title to
   * @param body
   *            value to set note body to
   * @return true if the note was successfully updated, false otherwise
   */
  public boolean updateNote(long rowId, String title, String body) {
    ContentValues args = new ContentValues();
    args.put(KEY_TITLE, title);
    args.put(KEY_BODY, body);

    return mDb.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;
  }
}

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