hm-lok

DataBaseHelper.java (3983B)

---

 package de.jandankert.hansemerkur.db;
 
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 
 import android.content.Context;
 import android.database.SQLException;
 import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteException;
 import android.database.sqlite.SQLiteOpenHelper;
 import android.util.Log;
 
 public class DataBaseHelper extends SQLiteOpenHelper
 {
 
 	private static final int VERSION = 2;
 
 	// The Android's default system path of your application database.
 	private static String DB_PATH = "/data/data/de.jandankert.hansemerkur/databases/";
 
 	private static String DB_NAME = "hm.db";
 
 	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 DataBaseHelper(Context context)
 	{
 
 		super(context, DB_NAME, null, VERSION);
 		this.myContext = context;
 	}
 
 	/**
 	 * Creates a empty database on the system and rewrites it with your own
 	 * database.
 	 * */
 	public void createDataBase() throws IOException
 	{
 
 		boolean dbExist = checkDataBase();
 		// dbExist = false;
 
 		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();
 
 			try
 			{
 
 				copyDataBase();
 
 			} catch (IOException e)
 			{
 
 				throw new Error("Error copying database");
 
 			}
 		}
 
 	}
 
 	/**
 	 * 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
 							| SQLiteDatabase.NO_LOCALIZED_COLLATORS);
 
 		} catch (SQLiteException e)
 		{
 
 			// database does't exist yet.
 
 		}
 
 		if (checkDB != null)
 		{
 
 			checkDB.close();
 
 		}
 
 		return checkDB != null;
 	}
 
 	/**
 	 * 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() throws IOException
 	{
 
 		// 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();
 
 	}
 
 	public void openDataBase() throws SQLException
 	{
 
 		// Open the database
 		String myPath = DB_PATH + DB_NAME;
 		myDataBase = SQLiteDatabase.openDatabase(myPath, null,
 				SQLiteDatabase.OPEN_READONLY
 						| SQLiteDatabase.NO_LOCALIZED_COLLATORS);
 
 	}
 
 	@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)
 	{
 		
 //		try
 //		{
 //			this.copyDataBase();
 //		} catch (IOException e)
 //		{
 //			Log.w("DB",e);
 //		}
 	}
 
 	// Add your public helper methods to access and get content from the
 	// database.
 	// You could return cursors by doing "return myDataBase.query(....)" so it'd
 	// be easy
 	// to you to create adapters for your views.
 
 }