DBHandler.java

public class DBHandler extends SQLiteOpenHelper{
 
    //The Android's default system path of your application database
    //Replace net.cialu.dbhandler with you Application package nae
    //This should be same as which you used package section in your manifest
    private static String DB_PATH = "/data/data/net.cialu.dbhandler/databases/";
 
    //replace this with name of your db file which you copied into asset folder
    private static String DB_NAME = "database_name";
 
    private SQLiteDatabase myDataBase; 
 
    private final Context myContext;
 
    /**
     * Constructor
     * Takes and keeps a reference of the passed context in order to access to the application assets and resources.
     * @param context
     */
    public DBHandler(Context context) {
 
    	super(context, DB_NAME, null, 1);
        this.myContext = context;
        this.createDataBase();
    }	
 
    /**
     * Creates a empty database on the system and rewrites it with your own database.
     * */
    public void createDataBase(){
    	try {
    	boolean dbExist = checkDataBase();
 
    	if(dbExist){
    		//do nothing - database already exist
    	}else{
    		//By calling this method and empty database will be created into the default system path
                //of your application so we are gonna be able to overwrite that database with our database.
        	this.getReadableDatabase();
        	
 
    			copyDataBase();
 
    		}
    	}
    	catch (Exception e) {

        	}
    }
 
    /**
     * Check if the database already exist to avoid re-copying the file each time you open the application.
     * @return true if it exists, false if it doesn't
     */
    private boolean checkDataBase(){
 
    	SQLiteDatabase checkDB = null;
 
    	try{
    		String myPath = DB_PATH + DB_NAME;
    		checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
 
    	}catch(SQLiteException e){
 
    		//database does't exist yet.
    		
    	}
 
    	if(checkDB != null){
 
    		checkDB.close();
 
    	}
 
    	return checkDB != null ? true : false;
    }
 
    /**
     * Copies your database from your local assets-folder to the just created empty database in the
     * system folder, from where it can be accessed and handled.
     * This is done by transfering bytestream.
     * */
    private void copyDataBase(){
 
    	try{
    	//Open your local db as the input stream
    	InputStream myInput = myContext.getAssets().open(DB_NAME);
 
    	// Path to the just created empty db
    	String outFileName = DB_PATH + DB_NAME;
 
    	//Open the empty db as the output stream
    	OutputStream myOutput = new FileOutputStream(outFileName);
 
    	//transfer bytes from the inputfile to the outputfile
    	byte[] buffer = new byte[1024];
    	int length;
    	while ((length = myInput.read(buffer))>0){
    		myOutput.write(buffer, 0, length);
    	}
 
    	//Close the streams
    	myOutput.flush();
    	myOutput.close();
    	myInput.close();
    	}
    	catch (Exception e) {
			//catch exception
		}
    }
 
    public SQLiteDatabase openDataBase() throws SQLException{
 
    	//Open the database
        String myPath = DB_PATH + DB_NAME;
    	myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
    	return myDataBase;
 
    }
 
  @Override
	public synchronized void close() {
 
    	    if(myDataBase != null)
    	    { myDataBase.close();}
 
    	    super.close();
 
	}
 
	@Override
	public void onCreate(SQLiteDatabase db) {
 
	}
 
	@Override
	public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
 
	}
 
 
}