GoogleAccountsAuthenticationEntryPoint.java

package org.waterforpeople.mapping.app.web.rest.security;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.AuthenticationEntryPoint;

import com.google.appengine.api.users.UserService;
import com.google.appengine.api.users.UserServiceFactory;

public class GoogleAccountsAuthenticationEntryPoint implements AuthenticationEntryPoint {

    public void commence(HttpServletRequest request, HttpServletResponse response,
            AuthenticationException authException)
            throws IOException, ServletException {
        UserService userService = UserServiceFactory.getUserService();

        response.sendRedirect(userService.createLoginURL(request.getRequestURI()));
    }
}