title: DatabaseManager has no default constructor
body: <p>Hy Guys!</p>
  
  <p>My problem is that Android is showing me an Error which says that I've no default constructor class. The Error occurs in the AndroidManifest.</p>
  
  <p>Here is my Code:</p>
  
  <pre><code>package at.atn.android;
  
  import android.database.sqlite.SQLiteDatabase;
  import android.database.sqlite.SQLiteOpenHelper;
  import android.content.Context;
  import android.database.sqlite.SQLiteException;
  import android.database.SQLException;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.io.FileOutputStream;
  
  public class DatabaseHelper extends SQLiteOpenHelper {
  //The Android's default system path of your application database.
  private static String DB_PATH = "/data/data/at.atn.android/databases/";
  
  public static String DB_NAME = "db.sqlite3";
  
  private SQLiteDatabase myDataBase;
  
  private final Context myContext;
  
  
  @Override
  public void onCreate(SQLiteDatabase db) {
  }
  
  @Override
  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
  
  }
  
  /**
   * 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)) &gt; 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();
  
  }
  
  // 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.
  </code></pre>
  
  <p>}</p>
  
  <p>Android Manifest:</p>
  
  <pre><code>&lt;application
      android:allowBackup="true"
      android:icon="@drawable/bus"
      android:label="@string/app_name"
      android:theme="@android:style/Theme.Light.NoTitleBar.Fullscreen" &gt;
      &lt;activity
          android:name="at.atn.android.MainActivity"
          android:label="@string/app_name" &gt;
          &lt;intent-filter&gt;
              &lt;action android:name="android.intent.action.MAIN" /&gt;
  
              &lt;category android:name="android.intent.category.LAUNCHER" /&gt;
          &lt;/intent-filter&gt;
      &lt;/activity&gt;
      &lt;activity android:name="at.atn.android.PlanActivity"&gt;&lt;/activity&gt;
      &lt;activity android:name="at.atn.android.InfoActivity"&gt;&lt;/activity&gt;
      &lt;activity android:name="at.atn.android.PlanAusgabeSubActivity"&gt;&lt;/activity&gt;
      &lt;activity android:name="at.atn.android.SetzeZeitActivity"&gt;&lt;/activity&gt;
      &lt;activity android:name="at.atn.android.ListHaltestelleActivity"/&gt;
      &lt;activity android:name="at.atn.android.AktualisiereDB"&gt;&lt;/activity&gt;
      &lt;activity android:name="at.atn.android.DatabaseHelper"&gt;&lt;/activity&gt;
  &lt;/application&gt;
  </code></pre>
  
  <p>Thanks for helping me!</p>