Android Open Source - sqlite my D B Content Provider

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License

The source code is released under:

GNU General Public License

Java Source Code

package edu.cs4730.sqlitedemo;
/*  w  w  w . j  av a  2s .  co  m*/
import android.content.ContentProvider;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteQueryBuilder;
import android.net.Uri;

public class myDBContentProvider extends ContentProvider {

  /*
   * used the following for a lot of information
   * http://thinkandroid.wordpress.com/2010/01/13/writing-your-own-contentprovider/
   * 
   * We could use the ScoreDatabase, but it is not very generic and we need to create
   * generic methods to handle some of the requests, instead just creating them here.
   * Plus need  to add stuff for the loader classes as well.
   * 
   * As a note, this provides a nearly generic content provider for any database.
   * specific database names, columns would need to be changed, but otherwise, should
   * work for most databases.
   */
  
  public static final String PROVIDER_NAME = "edu.cs4730.scoreprovider";

  public static final Uri CONTENT_URI = 
      Uri.parse("content://"+ PROVIDER_NAME + "/score");

    private static final int SCORE = 1;
    private static final int SCORE_ID = 2;   
    
  private static final UriMatcher uriMatcher;
  static{
    uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
    uriMatcher.addURI(PROVIDER_NAME, "score", SCORE);
    uriMatcher.addURI(PROVIDER_NAME, "score/#", SCORE_ID);
  }

  static final String TAG = "myDBCP";
  
  //the database to be used in the contenProvider
  mySQLiteHelper myDB;
  

  @Override
  public String getType(Uri uri) {
    switch (uriMatcher.match(uri)) {
    // get all rows
    case SCORE:
      return "vnd.android.cursor.dir/vnd.cs4730.score";
      // get a particular row
    case SCORE_ID:
      return "vnd.android.cursor.item/vnd.cs4730.score";
    default:
      throw new IllegalArgumentException("Unsupported URI: " + uri);
    }
  }
  
  @Override
  public boolean onCreate() {
    myDB = new mySQLiteHelper(getContext());
    return myDB != null;
  }

  /*
   * So delete is a simple function
   * 
   * example here, we are just provider a wrapper to the delete function.
   * db.delete(mySQLiteHelper.DATABASE_TABLE, selection, selectionArgs);
   * would looke like:
   * "delete from " + tableName + " where " + selection + " ? " + selectionArgs"
   *  and a fix where they are deleted by score/#, so providing _id and number. 
   *  
   */
  @Override
  public int delete(Uri uri, String selection, String[] selectionArgs) {
        SQLiteDatabase db = myDB.getWritableDatabase();
          switch (uriMatcher.match(uri)) {
              case SCORE:
                  break;
              case SCORE_ID:
                  selection = selection + "_id = " + uri.getLastPathSegment();
                  break;
              default:
                  throw new IllegalArgumentException("Unknown URI " + uri);
          }
   
          int count = db.delete(mySQLiteHelper.DATABASE_TABLE, selection, selectionArgs);
          getContext().getContentResolver().notifyChange(uri, null);
          return count;
  }
  /*
   *   For the query method, but need to provide a couple more piece of information to the query
   * but are null values, plus pass onthe sortOrder on to it. 
   */
  @Override
  public Cursor query(Uri uri, String[] projection, String selection,
      String[] selectionArgs, String sortOrder) {
        SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
          qb.setTables(mySQLiteHelper.DATABASE_TABLE);
   
          switch (uriMatcher.match(uri)) {   
              case SCORE:
                  break;
              case SCORE_ID:
                  selection = selection + "_id = " + uri.getLastPathSegment();
                  break;
              default:
                  throw new IllegalArgumentException("Unknown URI " + uri);
          }
   
          SQLiteDatabase db = myDB.getReadableDatabase();
          Cursor c = qb.query(db, projection, selection, selectionArgs, null, null, sortOrder);
   
          c.setNotificationUri(getContext().getContentResolver(), uri);  //for notifications and loader classes if used.
          return c;
  }

  @Override
  public Uri insert(Uri uri, ContentValues values) {
        if (uriMatcher.match(uri) != SCORE) {  //can't insert by id number, so only generic is allowed.
            throw new IllegalArgumentException("Unknown URI " + uri);
        }
 
        if (values == null) {   //basic error checking.  values is null, provider an empty one
            values = new ContentValues();  //or we could through an SQLExecption as well.
        }
 
        SQLiteDatabase db = myDB.getWritableDatabase();
        long rowId = db.insert(mySQLiteHelper.DATABASE_TABLE, null, values);
        if (rowId > 0) {
            Uri noteUri = ContentUris.withAppendedId(CONTENT_URI, rowId);
            getContext().getContentResolver().notifyChange(noteUri, null);
            return noteUri;
        }
 
        throw new SQLException("Failed to insert row into " + uri);
  }


  @Override
  public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
        SQLiteDatabase db = myDB.getWritableDatabase();
        int count;
        switch (uriMatcher.match(uri)) {
            case SCORE:  break;
            
            case SCORE_ID:  
              selection = selection + "_id = "+uri.getLastPathSegment();
                break;
            default:
                throw new IllegalArgumentException("Unknown URI " + uri);
        }
        count = db.update(mySQLiteHelper.DATABASE_TABLE, values, selection, selectionArgs);
        getContext().getContentResolver().notifyChange(uri, null);
        return count;
  }
  


}

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