DataBaseHelper.java

/**
 * 
 */
package com.engg.solution;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;

/**
 * @author Badrinath
 * 
 */
public class DataBaseHelper extends SQLiteOpenHelper {

	// Path Name
	private static String DB_PATH = "/data/data/com.engg.solution/databases/";

	// Database name
	//private static String DB_NAME = "Questions.sqlite";
	
	//private static String DB_NAME = "testy.sqlite";

	private static String DB_NAME = "answer.sqlite";


	private Context mycontext;

	public SQLiteDatabase myDataBase;

	public DataBaseHelper(Context context) throws IOException {
		super(context, DB_NAME, null, 1);
		this.mycontext = context;
		boolean dbexist = checkdatabase();
		if (dbexist) {
			System.out.println("Database exists");
			opendatabase();
		} else {
			System.out.println("Database doesn't exist");
			createdatabase();
		}

	}
	public void createdatabase() throws IOException{
	    boolean dbexist = checkdatabase();
	    if(dbexist)
	    {
	        System.out.println(" Database exists.");
	    }
	    else{
	    	this.getReadableDatabase();
	    try{
	            copydatabase();
	        }
	        catch(IOException e){
	            throw new Error("Error copying database");
	        }
	    }
	}

	
	private boolean checkdatabase() {
	    //SQLiteDatabase checkdb = null;
	    boolean checkdb = false;
	    try{
	        String myPath = DB_PATH + DB_NAME;
	        File dbfile = new File(myPath);
	        //checkdb = SQLiteDatabase.openDatabase(myPath,null,SQLiteDatabase.OPEN_READWRITE);
	        checkdb = dbfile.exists();
	    }
	    catch(SQLiteException e){
	        System.out.println("Database doesn't exist");
	    }

	    return checkdb;
	}

	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 byte to inputfile to 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_READWRITE);

	}



	public synchronized void close(){
	    if(myDataBase != null){
	        myDataBase.close();
	    }
	    super.close();
	}  
	@Override
	public void onCreate(SQLiteDatabase db) {
		// TODO Auto-generated method stub
		/*Cursor cur =myDataBase.rawQuery("SELECT questiondata.question FROM main.questiondata",null);
		while(cur.moveToFirst()){
			System.out.println(cur.getString(0));
		}*/
	}
	@Override
	public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
		// TODO Auto-generated method stub
		
	}

	
	public Cursor getAnswer(String qustn) 
    {
        return myDataBase.query("main.data", new String[] {
        		"data.ans"}, 
        		"data.qustn"+" = '"+qustn+ "'", 
                null, 
                null, 
                null, 
                null);
    }
}