Database helper class in Android

import java.util.ArrayList;

import java.util.List;

import java.util.Locale;

import android.app.Activity;

import android.content.ContentValues;

import android.database.Cursor;

import android.database.sqlite.SQLiteDatabase;

public class Database{

SQLiteDatabase db;

String DB_NAME="test.db";

String root="data/data/com.example.test/";

 

String DB_FULL_PATH=root+"databases/"+DB_NAME;

int Rcount=0;

public void CreateDB(Activity a) {

 

        this.db = a.openOrCreateDatabase(

        DB_NAME

      , SQLiteDatabase.CREATE_IF_NECESSARY

      , null

      );

       

       

        db.setVersion(1);

        db.setLocale(Locale.getDefault());

        db.setLockingEnabled(true);

       

}

 

public void OpenDB(Activity a) {

 

this.db = SQLiteDatabase.openDatabase(DB_FULL_PATH, null,

                SQLiteDatabase.OPEN_READWRITE);

       

}

 

 public void CloseDB(Activity a) { 

this.db.close();       

}

public boolean checkDataBase() {

    SQLiteDatabase checkDB = null;

    try {

       

checkDB = SQLiteDatabase.openDatabase(DB_FULL_PATH, null,

                SQLiteDatabase.OPEN_READONLY);

        checkDB.close();

    } catch (Exception e) {

        // database doesn't exist yet.

    }

    return checkDB != null ? true : false;

}

public void CreateTable( String CREATE_TABLE){

db.execSQL(CREATE_TABLE);

}

//String s="CREATE TABLE user (ID INTEGER PRIMARY KEY, phone NUMERIC, Name TEXT)";

public void insertDB(ContentValues values,String table) {

//db.insert(table, null, values); // it will create new rows and wont merge if already exist. i.e. insert

db.replace(table, null, values); // it will merge data in existing rows or else creates new row .i.e insert or update

}

public Cursor resultDB(String query) {

//Vector vector = new Vector();

String res="";

Cursor cur = db.rawQuery(query,new String[]{});

Rcount=cur.getCount();      

return cur;

}

public String[] getAllResultStr(String query,int pos)

    {

        Cursor cursor = db.rawQuery(query,new String[]{});

        if(cursor.getCount() >0)

        {

            String[] str = new String[cursor.getCount()];

            int i = 0;

            while (cursor.moveToNext())

            {

                 str[i] = cursor.getString(pos);

                 i++;

             }

            cursor.close();

            return str;

        }

        else

        {  cursor.close();

            return new String[] {};

        }

    }

public List getAllResultList(String query,int pos)

    {

        Cursor cursor = db.rawQuery(query,new String[]{});

        List list=new ArrayList(10);

        if(cursor.getCount() >0)

        while (cursor.moveToNext())

                list.add( cursor.getString(pos)) ;

        

        return list;

    }

public int getRowCount() {

return Rcount;

}

public void updateDB(ContentValues values,String tbname,String whereClause,String [] whereArgs) {

db.update(tbname,values, whereClause, whereArgs);

}

public void deleteDB(String TABLE_NAME,String WHERE,String[] args) {

db.delete(TABLE_NAME,WHERE,args);

}

}

RandomFileWriter in Andriod

import java.io.File;

import java.io.RandomAccessFile;

import android.os.Environment;

import android.util.Log;

public class RandomFileWriter {

public long writeData(String text,String path,long seek){

try {
// example path : "/data/data/com.example.test/file"

RandomAccessFile file = new RandomAccessFile(path, "rw");

long i=file.length()-seek,j;

Log.i("File length",""+i);

file.seek(i);

file.writeBytes(text);

j=file.getFilePointer();

file.close();

return j;

}catch (Exception e) {

// TODO Auto-generated catch block

Log.d("RandomFileWrite.java","Exception: "+e.getMessage());

return 0;

}

 

}

public void seekWrite(String text,String path,long seek) {

try {

RandomAccessFile file = new RandomAccessFile(path, "rw");

file.seek(seek);

file.writeBytes(text);

file.close();

} catch (Exception e) {

// TODO Auto-generated catch block

Log.d("RandomFileWrite.java seekwrite","Exception: "+e.getMessage());

}

}

String getExternalPath(){

return Environment.getExternalStorageDirectory().toString();

}

boolean isMediaReadOnly(){

String state = Environment.getExternalStorageState();

if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {

    // We can only read the media

   

  return true;

}

return false;

}

boolean isMediaMounted(){

String state = Environment.getExternalStorageState();

if (Environment.MEDIA_MOUNTED.equals(state)) {

    // We can read and write the media

    Log.i("Exter", "media found: "+Environment.getExternalStorageDirectory());

  return true;

} 

return false;

}

public void createDir(String path,String dir){

new File(path+dir).mkdir();

}

public void createDir(File dirPath){

dirPath.mkdir();

}

public boolean deleteDir(File dir) {

    if (dir.isDirectory()) {

        String[] children = dir.list();

        for (int i=0; ilength; i++) {

            boolean success = deleteDir(new File(dir, children[i]));

            if (!success) {

                return false;

            }

        }

    }

    // The directory is now empty so delete it

    return dir.delete();

}

public boolean delFile(File f){

return f.delete();

 

}

void copy(File src, File dst) throws Exception{

    // Transfer bytes from in to out

    byte[] buf = new byte[1024];

    int len;

   

    RandomAccessFile in = new RandomAccessFile(src, "r");

RandomAccessFile out = new RandomAccessFile(dst, "rw");

    while ((len = in.read(buf)) > 0) {

        out.write(buf, 0, len);

    }

    in.close();

    out.close();

   

}

}