EDIT

package eu.etaxonomy.cdm.remote.vaadin.components;

import java.io.Serializable;

import javax.annotation.PostConstruct;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.context.annotation.Scope;

import org.springframework.security.core.AuthenticationException;

import org.springframework.stereotype.Component;

import com.vaadin.data.validator.StringLengthValidator;

import com.vaadin.event.ShortcutAction.KeyCode;

import com.vaadin.server.Page;

import com.vaadin.ui.Button;

import com.vaadin.ui.Button.ClickEvent;

import com.vaadin.ui.FormLayout;

import com.vaadin.ui.Label;

import com.vaadin.ui.Notification;

import com.vaadin.ui.PasswordField;

import com.vaadin.ui.TextField;

import com.vaadin.ui.UI;

import eu.etaxonomy.cdm.remote.vaadin.service.VaadinAuthenticationService;

import eu.etaxonomy.cdm.remote.vaadin.uiset.redlist.views.ClassificationSelectorView;

/**

 * 

 * 

 * Yet another component, which creates a simple login form layout. It makes use of the 

 * AuthenticationController.

 * 

 * 

 * @author a.oppermann

 *

 */

@Component

@Scope("prototype")

public class LoginForm extends FormLayout implements Serializable{

    /**

	 * Automatically generated serial version ID

	 */

	private static final long serialVersionUID = 8409330855620204572L;

	private static final String COMMON_FIELD_WIDTH = "12em";

	@Autowired

	private transient VaadinAuthenticationService authenticationController;

	private TextField userName;

	private PasswordField passwordField;

    @PostConstruct

	public void PostConstruct(){

		// userName

		userName = new TextField();

		userName.setRequired(true);

		userName.setRequiredError("Please enter a valid user name!");

		userName.setCaption("Username");

		userName.setImmediate(false);

        userName.addValidator(new StringLengthValidator("It must be 3-25 characters", 3, 25, false));

		userName.setWidth(COMMON_FIELD_WIDTH);

		userName.setNullRepresentation("");

		userName.focus();

		// passwordField

		passwordField = new PasswordField();

		passwordField.setRequired(true);

		passwordField.setRequiredError("Please enter a valid password!");

		passwordField.addValidator(new StringLengthValidator("It must be 3-25 characters", 3, 25, false));

		passwordField.setCaption("Password");

		passwordField.setImmediate(false);

		passwordField.setWidth(COMMON_FIELD_WIDTH);

		// sendButton

		Button sendButton = new Button("Send", new Button.ClickListener() {

			/**

			 * Automatically generated serial version ID

			 */

			private static final long serialVersionUID = -4423849632134093870L;

			@Override

			public void buttonClick(ClickEvent event) {

				try{

					boolean isAuthenticated = authenticationController.authenticate(userName.getValue(), passwordField.getValue());

					if(isAuthenticated){

						UI.getCurrent().getSession().setAttribute("isAuthenticated", isAuthenticated);

						Page.getCurrent().setUriFragment("!"+ ClassificationSelectorView.NAME);//DashBoardView BfnView.NAME

					}

				}catch(AuthenticationException e){

					Notification.show("Bad credentials",Notification.Type.ERROR_MESSAGE);

				}

			}

		});

		sendButton.setClickShortcut(KeyCode.ENTER, null);

		sendButton.setCaption("Send");

		sendButton.setImmediate(true);

		Label header = new Label("Vaaditor login...");

		Label label = new Label("Bitte melden Sie sich mit Ihrem Benutzernamen und Passwort an.");

		header.setStyleName("h1");

		setSpacing(true);

		setMargin(true);

		setSizeUndefined();

		addComponent(header);

		addComponent(label);

		addComponent(userName);

		addComponent(passwordField);

		addComponent(sendButton);

	}

}