Witam
Piszę aplikację na Androida, która łączy się z już wcześniej stworzoną bazą danych.
package com.example.database;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import com.example.list.RowBean;
public class DataBaseHelper extends SQLiteOpenHelper
{
private Context context;
private SQLiteDatabase myDataBase;
private String DB_PATH;
private static final String DB_NAME = "database.sqlite";
public DataBaseHelper(Context context)
{
super(context, DB_NAME, null, 1);
this.context = context;
DB_PATH = context.getApplicationContext().getPackageName()+"/databases/" + DB_NAME;
}
// Create and open Application database.
public void createDB()
{
// Create database if not exist.
if(!isDBExistInApp())
{
this.getReadableDatabase();
copyDBFromResourceToApp();
}
// Open database.
openDB();
}
// Check if database exist in Application.
private boolean isDBExistInApp()
{
SQLiteDatabase db = null;
try
{
db = SQLiteDatabase.openDatabase(DB_PATH, null, SQLiteDatabase.OPEN_READWRITE);
}
catch(SQLiteException e) { throw new Error("Database not found."); }
return db != null ? true : false;
}
// Copy database to Application from resource.
private void copyDBFromResourceToApp()
{
try
{
// Create streams.
InputStream inputStream = context.getAssets().open(DB_NAME);
OutputStream outputStream = new FileOutputStream(DB_PATH);
byte[] buffer = new byte[1024];
int length;
while((length = inputStream.read(buffer)) > 0)
outputStream.write(buffer, 0, length);
// Close streams.
outputStream.flush();
outputStream.close();
inputStream.close();
}
catch(IOException e) {throw new Error("An error has occured when copying database.");}
}
// Get and return data from Application database.
public List<RowBean> getData()
{
List<RowBean> itemsList = new ArrayList<RowBean>();
List<String> nameList = new ArrayList<String>();
List<Bitmap> iconList = new ArrayList<Bitmap>();
byte[] icon;
Bitmap bm;
Cursor cursor = myDataBase.rawQuery("SELECT * FROM Class", null);
if(cursor.moveToFirst())
{
do {
nameList.add(cursor.getString(cursor.getColumnIndex("Name")));
icon = cursor.getBlob(cursor.getColumnIndex("Image"));
bm = BitmapFactory.decodeByteArray(icon, 0 ,icon.length);
iconList.add(bm);
}
while(cursor.moveToNext());
for(int i = 0; i < nameList.size(); i++)
itemsList.add(new RowBean(iconList.get(i), nameList.get(i)));
}
return itemsList;
}
public void openDB()
{
myDataBase = SQLiteDatabase.openDatabase(DB_PATH, null, SQLiteDatabase.OPEN_READWRITE);
}
public void close()
{
if(myDataBase != null)
myDataBase.close();
super.close();
}
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {}
public void onCreate(SQLiteDatabase db) {}
}
Kod uruchamiający bazę danych:
DataBaseHelper dbHelper = new DataBaseHelper(this);
dbHelper.createDB();
dbHelper.openDB();
itemsList = dbHelper.getData();
dbHelper.close();
LogCat:
08-06 20:49:37.180: E/SQLiteLog(19734): (14) cannot open file at line 30202 of [00bb9c9ce4]
08-06 20:49:37.180: E/SQLiteLog(19734): (14) os_unix.c:30202: (2) open(//com.example.keys/databases/database.sqlite) -
08-06 20:49:37.185: E/SQLiteDatabase(19734): Failed to open database 'com.example.keys/databases/database.sqlite'.
08-06 20:49:37.185: E/SQLiteDatabase(19734): android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:209)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:193)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:463)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:185)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:177)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:804)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:789)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:694)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:669)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at com.example.database.DataBaseHelper.isDBExistInApp(DataBaseHelper.java:56)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at com.example.database.DataBaseHelper.createDB(DataBaseHelper.java:40)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at com.example.activity.ClassActivity.onCreate(ClassActivity.java:40)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.app.Activity.performCreate(Activity.java:5135)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1150)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2432)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2530)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.app.ActivityThread.access$600(ActivityThread.java:176)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1385)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.os.Handler.dispatchMessage(Handler.java:107)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.os.Looper.loop(Looper.java:194)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at android.app.ActivityThread.main(ActivityThread.java:5546)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at java.lang.reflect.Method.invokeNative(Native Method)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at java.lang.reflect.Method.invoke(Method.java:525)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:606)
08-06 20:49:37.185: E/SQLiteDatabase(19734): at dalvik.system.NativeStart.main(Native Method)
08-06 20:49:37.185: D/AndroidRuntime(19734): Shutting down VM
Proszę o wyrozumiałość, to moja pierwsza aplikacja z bazą danych.
Android 
SQLite 