Controller

GreetingController.java

package org.springSecurityLogin.controller;

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

import org.springframework.security.core.Authentication;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.web.authentication.logout.SecurityContextLogoutHandler;
import org.springframework.stereotype.Controller;
import org.springframework.util.ObjectUtils;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.servlet.ModelAndView;

@Controller
public class GreetingController {

	@RequestMapping(value = { "/", "/index" }, method = RequestMethod.GET)
	public ModelAndView indexPage() {

		ModelAndView model = new ModelAndView();
		model.addObject("greeting", "WELCOME - Spring Security Greeting");
		model.setViewName("index");
		return model;

	}

	@RequestMapping(value = "/admin", method = RequestMethod.GET)
	public ModelAndView adminPage() {

		ModelAndView model = new ModelAndView();
		model.addObject("msg", "Hi " + getPrincipal()
				+ ", welcome to ADMIN page!");
		model.setViewName("admin");

		return model;

	}

	@RequestMapping(value = "/login", method = RequestMethod.GET)
	public ModelAndView login(
			@RequestParam(value = "error", required = false) String error,
			@RequestParam(value = "logout", required = false) String logout) {

		ModelAndView model = new ModelAndView();
		if (error != null) {
			model.addObject("error", "Invalid username and password!");
		}

		if (logout != null) {
			model.addObject("msg", "You've been logged out successfully.");
		}
		model.setViewName("login");

		return model;

	}

	@RequestMapping(value = "/logout", method = RequestMethod.GET)
	public String logoutPage(HttpServletRequest request,
			HttpServletResponse response) {
		Authentication auth = SecurityContextHolder.getContext()
				.getAuthentication();
		if (auth != null) {
			new SecurityContextLogoutHandler().logout(request, response, auth);
		}
		return "redirect:/login?logout=true";
	}

	@RequestMapping(value = "/403", method = RequestMethod.GET)
	public ModelAndView accesssDenied() {

		ModelAndView model = new ModelAndView();

		String user = getPrincipal();

		if (!ObjectUtils.isEmpty(user)) {
			model.addObject("msg", "Hi " + user
					+ ", you do not have permission to access this page!");
		} else {
			model.addObject("msg",
					"You do not have permission to access this page!");
		}

		model.setViewName("403");
		return model;

	}

	@RequestMapping(value = "/db", method = RequestMethod.GET)
	public ModelAndView dba() {

		ModelAndView model = new ModelAndView();
		model.addObject("msg", "Hi " + getPrincipal()
				+ ", welcome to DBA page!");
		model.setViewName("db");
		return model;

	}

	/**
	 * Get current user with login
	 * 
	 * @return String - user name
	 */
	private String getPrincipal() {
		String userName = null;
		Object principal = SecurityContextHolder.getContext()
				.getAuthentication().getPrincipal();

		if (principal instanceof UserDetails) {
			userName = ((UserDetails) principal).getUsername();
		} else {
			userName = principal.toString();
		}
		return userName;
	}
}