當使用者通過認證，意即登入後，除了可以存取網頁資訊外，某些網頁元素是可以透過Spring Security Tag來決定使用者是否可以看的到，但今天先以最簡單為例，登入後可以看到logout的連結，並顯示Hi, 登入帳號名稱並顯示logout連結，如果未登錄導覽列顯示login連結，要使用Spring Security Tag，必須先加入以下dependency

<dependency>
      <groupId>org.springframework.security</groupId>
      <artifactId>spring-security-taglibs</artifactId>
      <version>${security.version}</version>
      <scope>compile</scope>
</dependency>

<properties>
    <security.version>3.2.5.RELEASE</security.version>
 </properties>

先修改導覽列，修改base.jsp code如下:

<%@ taglib prefix="sec" uri="http://www.springframework.org/security/tags" %>  


....


<nav class="navigation-bar dark">
		<nav class="navigation-bar-content container">
			.....
				<li><a href="#">About Us</a></li>
			</ul>
			<sec:authorize access="authenticated" var="authenticated" />
			<c:choose>
				<c:when test="${authenticated}">
					<div class="element place-right">
						<p class="text-right fg-white">
							Hi,
							<sec:authentication property="name" />
							<a href="<spring:url value="/logout"/>"
								class="button link">Log out</a>
						</p>
					</div>
				</c:when>
				<c:otherwise>
					<a class="element place-right" href="<spring:url value="/login"/>">Log in</a>			
				</c:otherwise>
			</c:choose>
			<span class="element-divider place-right"></span>
		</nav>
	</nav>
      ....

<sec:authorize access="">標籤用來設定存取權限，這邊用的關鍵字authenticated，意思是只要登過帳號驗證，即可有權限存取，搭配<c:choose>，當使用者登入，即authenticated，則顯示Hi, 使用者名稱，使用者名稱變數，可以透過<sec:authorize property=name/>取得，並接著一個logout的button連結，其他其況(<c:otherwise>)則顯示login連結。

啟動Server，未登入畫面

以admin 帳號登入，畫面如下

同樣的本文也可以用<c:choose>換掉原本的文字

Logout的部分，參考官方文件

我自己寫一個簡單的controller，其code如下:

@RequestMapping(value="/logout", method=RequestMethod.GET)
	public String logout(HttpServletRequest req) throws ServletException{
		req.logout();
		return "redirect:/";
	}

Console log:

23:56:56 [http-nio-8080-exec-4] DispatcherServlet - DispatcherServlet with name 'dispatcher' processing GET request for [/SpringMVC/logout]
23:56:56 [http-nio-8080-exec-4] RequestMappingHandlerMapping - Looking up handler method for path /logout
23:56:56 [http-nio-8080-exec-4] RequestMappingHandlerMapping - Returning handler method [public java.lang.String tw.blogger.springtech.springmvc.controller.DefaultController.logout(javax.servlet.http.HttpServletRequest) throws javax.servlet.ServletException]
23:56:56 [http-nio-8080-exec-4] DispatcherServlet - Last-Modified value for [/SpringMVC/logout] is: -1
23:56:56 [http-nio-8080-exec-4] ContentNegotiatingViewResolver - Requested media types are [text/html, application/xhtml+xml, application/xml;q=0.9, */*;q=0.8] based on Accept header types and producible media types [*/*])
23:56:56 [http-nio-8080-exec-4] ContentNegotiatingViewResolver - Returning redirect view [org.springframework.web.servlet.view.RedirectView: name 'redirect:/'; URL [/]]
23:56:56 [http-nio-8080-exec-4] DispatcherServlet - Rendering view [org.springframework.web.servlet.view.RedirectView: name 'redirect:/'; URL [/]] in DispatcherServlet with name 'dispatcher'
23:56:56 [http-nio-8080-exec-4] DispatcherServlet - Successfully completed request