Program: 108548
Project: 108548
Buggy source:
/** 
 * Connects to the database This tries to establish an JDBC connection. In case of an error appropriate error messages are set. Otherwise the connection is passed on to   {@link ImportWizardModel}. The return value indicates whether a connection has been established.
 * @return True if successfully connected, false otherwise
 * @see {@link ImportWizardModel#setJdbcConnection(Connection)}
 */
protected boolean connect(){
  try {
    Connection connection=null;
    if (comboType.getText().equals(SQLITE)) {
      Class.forName("String_Node_Str");
      connection=DriverManager.getConnection("String_Node_Str" + comboLocation.getText());
    }
 else     if (comboType.getText().equals(MYSQL)) {
      Class.forName("String_Node_Str");
      connection=DriverManager.getConnection("String_Node_Str" + txtServer.getText() + "String_Node_Str"+ txtPort.getText()+ "String_Node_Str"+ txtDatabase.getText(),txtUsername.getText(),txtPassword.getText());
    }
 else     if (comboType.getText().equals(POSTGRESQL)) {
      Class.forName("String_Node_Str");
      connection=DriverManager.getConnection("String_Node_Str" + txtServer.getText() + "String_Node_Str"+ txtPort.getText()+ "String_Node_Str"+ txtDatabase.getText(),txtUsername.getText(),txtPassword.getText());
    }
    wizardImport.getData().setJdbcConnection(connection);
    return true;
  }
 catch (  ClassNotFoundException e) {
    setErrorMessage("String_Node_Str");
    return false;
  }
catch (  SQLException e) {
    setErrorMessage(e.getLocalizedMessage());
    return false;
  }
}

Fixed version (ground truth):
/** 
 * Connects to the database This tries to establish an JDBC connection. In case of an error appropriate error messages are set. Otherwise the connection is passed on to   {@link ImportWizardModel}. The return value indicates whether a connection has been established.
 * @return True if successfully connected, false otherwise
 * @see {@link ImportWizardModel#setJdbcConnection(Connection)}
 */
protected boolean connect(){
  try {
    Connection connection=null;
    if (comboType.getText().equals(SQLITE)) {
      Class.forName("String_Node_Str");
      connection=DriverManager.getConnection("String_Node_Str" + comboLocation.getText());
    }
 else     if (comboType.getText().equals(MYSQL)) {
      Class.forName("String_Node_Str");
      connection=DriverManager.getConnection("String_Node_Str" + txtServer.getText() + "String_Node_Str"+ txtPort.getText()+ "String_Node_Str"+ txtDatabase.getText(),txtUsername.getText(),txtPassword.getText());
    }
 else     if (comboType.getText().equals(POSTGRESQL)) {
      Class.forName("String_Node_Str");
      connection=DriverManager.getConnection("String_Node_Str" + txtServer.getText() + "String_Node_Str"+ txtPort.getText()+ "String_Node_Str"+ txtDatabase.getText(),txtUsername.getText(),txtPassword.getText());
    }
    try {
      if (!wizardImport.getData().getJdbcConnection().isClosed()) {
        wizardImport.getData().getJdbcConnection().close();
      }
    }
 catch (    Exception e) {
    }
    wizardImport.getData().setJdbcConnection(connection);
    return true;
  }
 catch (  ClassNotFoundException e) {
    setErrorMessage("String_Node_Str");
    return false;
  }
catch (  SQLException e) {
    setErrorMessage(e.getLocalizedMessage());
    return false;
  }
}