このチュートリアルhttp://www.reigndesign.com/blog/using-your-own-sqlite-database-in-android-applications/を使用して、Android アプリケーションで独自に作成したデータベースを使用しようとしています。
私の資産フォルダーにデータベースがあり、作業を回避するために5時間作業していますが、無駄です..私は常に取得し続けます
01-17 04:09:07.111: E/Database(1060): sqlite3_open_v2("/data/data/com.rahul.besttracker/databases/route", &handle, 1, NULL) failed
と
01-17 04:09:07.271: E/AndroidRuntime(1060): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.rahul.besttracker/com.rahul.besttracker.Busdisplay}: android.database.sqlite.SQLiteException: unable to open database file
私のコード
public class Busdisplay extends ListActivity {
TextView source, destination;
String src, dest;
ArrayList<String> mArrayList;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
init();
Bundle caught = getIntent().getExtras();
src = caught.getString("source");
dest = caught.getString("dest");
DataBaseHelper entry = null;
entry = new DataBaseHelper(Busdisplay.this);
entry.openDataBase();
mArrayList = entry.readEntry(src, dest);
entry.close();
setListAdapter(new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, mArrayList));
}
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
// TODO Auto-generated method stub
super.onListItemClick(l, v, position, id);
}
void init() {
source = (TextView) findViewById(R.id.textView1);
destination = (TextView) findViewById(R.id.textView2);
}
}
私の DBhelper クラス
public class DataBaseHelper extends SQLiteOpenHelper {
// The Android's default system path of your application database.
private static final String DB_PATH = "/data/data/com.rahul.besttracker/databases/";
private static final String DB_NAME = "route.db";
private static final String DB_TABLE1 = "route1";
private static final String DB_TABLE2 = "route2";
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) {
System.out.print("ERROR");
}
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_READONLY);
}
@Override
public synchronized void close() {
if (myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
try {
createDataBase();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + DB_TABLE1);
db.execSQL("DROP TABLE IF EXISTS " + DB_TABLE2);
onCreate(db);
}
public ArrayList<String> readEntry(String src, String dest) {
// TODO Auto-generated method stub
Cursor c = myDataBase.rawQuery("SELECT route_no from " + DB_TABLE1
+ " WHERE stops LIKE '%" + src + "%,%" + dest + "%';", null);
ArrayList<String> mArrayList = new ArrayList<String>();
int index = c.getColumnIndex("route_no");
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
// The Cursor is now set to the right position
mArrayList.add(c.getString(index));
}
return mArrayList;
}
// 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.
}