Android Open Source - android-roadkill Data Base Helper

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License

The source code is released under:
GNU General Public License
If you think the Android project android-roadkill listed in this page is inappropriate, such as containing malicious code/tools or violating the copyright, please email info at java2s dot com, thanks.
Java Source Code

package edu.ucdavis.cros.roadkill;
/*  ww w  .  j  a v a 2  s  .c  o m*/
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;

//http://www.reigndesign.com/blog/using-your-own-sqlite-database-in-android-applications/


public class DataBaseHelper extends SQLiteOpenHelper{
 
    //The Android's default system path of your application database.
    private static String DB_PATH = "/data/data/edu.ucdavis.cros.roadkill/databases/";
    private static String DB_NAME = "roadkill.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, 1);
        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();
 
      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);
 
      }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() 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_READWRITE);
 
    }
 
    @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) {
 
  }
 
        // 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.
  public Cursor spplist(){
    //Cursor mCursor = myDataBase.query("allspp",new String[] {"list"}, null, null, null, null, null);
    return myDataBase.query("allspp",new String[] {"list"}, null, null, null, null, null);
    //return mCursor;
  }
}
Java Source Code List
