Get Spring Security Principal in JSP EL expression

Question

I am using Spring MVC and Spring Security version 3.0.6.RELEASE. What is the easiest way to get the user name in my JSP? Or even just whether or not the user is logged in? I can think of a couple ways:

1. Using a scriptlet

Using a scriptlet like this to determine if the user is logged in:

<%=org.springframework.security.core.context.SecurityContextHolder.getContext()
    .getAuthentication().getPrincipal().equals("anonymousUser")
    ? "false":"true"%>

I'm not a fan of using scriptlets, though, and I want to use this in some <c:if> tags, which requires putting it back as a page attribute.

2. Using SecurityContextHolder

I could again use SecurityContextHolder from my @Controller and put it on the model. I need this on every page, though, so I'd rather not have to add this logic in every one of my Controllers.

I suspect there's a cleaner way to do this...

Answer 1

Check Spring security tags : <sec:authentication property="principal.username" />

http://static.springsource.org/spring-security/site/docs/3.0.x/reference/taglibs.html

And you can check if logged :

<sec:authorize access="isAuthenticated()"> 

instead of c:if

Answer 2

I know there are other answers in the thread, but none have answered how you can check if user is authenticated. So I'm sharing what my code look likes.

Include the tag lib in your project:

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

Then create a user object in current scope by adding:

<sec:authentication var="user" property="principal" />

Then you can easily show the username by adding. Remember the 'principal' object is generally of type string unless you have implemented the spring security in a way to change it to another Class in your project:

<sec:authorize access="hasRole('ROLE_USER') and isAuthenticated()">
${user}
</sec:authorize>

I hope this helps somebody looking to check user roles.

If you are using Maven, then add the dependency tag as mentioned by Christian Vielma in this thread.

Thanks!

Answer 3

You can use like this: Spring Security Tag Lib - 3.1.3.RELEASE

<sec:authentication var="principal" property="principal" />

and Then:

${principal.username}