Problème de constructeur SQLiteOpenHelper

Question

J'ai créé une base de données SQLite dans SQLiteBrowser. Je veux le référencer dans l'application Android, donc j'ai mis le fichier DB dans le dossier des actifs n utilisé le code suivant pour copier la base de données dans la mémoire App. M en utilisant éclipse pour le développement d'applications Android.

Mais le constructeur SQLiteOpenHelper génère une erreur. Le constructeur DB_Import (DB_test1) est indéfini

package com.example.DB_test1; 

public class DB_test1 extends Activity{ 
    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 
     DB_Import my_Import; 
     //SQLiteDatabase myDb = null; 
     my_Import=new DB_Import(this); 
     try {     
      my_Import.createDatabase(); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 
    } 

Voici un autre fichier de classe.

package com.example.DB_test1; 

public class DB_Import extends SQLiteOpenHelper{ 

    private final Context myContext; 
    String DB_PATH = "data/data/com.example.DB_test/databases/"; 
    String DB_NAME = "Dict_temp"; 
    private SQLiteDatabase myDatabase; 

    public DB_Import(Context context) { 
      super(context, "data/data/com.example.DB_test/databases/", null, 1); 
      this.myContext = context; 
     } 
    public void createDatabase()throws IOException{ 
      // TODO Auto-generated method stub 
      boolean dbExist = checkDatabase(); ////////////////Check if database Exist 
      if (dbExist) { 
       //openDatabase(); 
      }else { 
      this.getReadableDatabase(); 

      try { 
      copyDatabase(); ///////////////Copies the database from assets to android 
      } catch (IOException e) { 
      // TODO Auto-generated catch block 
      throw new Error("Error copying database"); 
      } 
      } 
     } 

Answer 1

Essayez ce code:

public class DataBaseHelper extends SQLiteOpenHelper{ 
private Context mycontext; 

private String DB_PATH = "/data/data/gr.peos/databases/"; 
//private String DB_PATH = mycontext.getApplicationContext().getPackageName()+"/databases/"; 
private static String DB_NAME = "BLib.sqlite";//the extension may be .sqlite or .db 
public SQLiteDatabase myDataBase; 
/*private String DB_PATH = "/data/data/" 
         + mycontext.getApplicationContext().getPackageName() 
         + "/databases/";*/ 

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("/data/data/gr.peos/databases/BLib.sqlite"); 

// 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(); 
}