在session中取得spring security的登录用户名如下:

${session.SPRING_SECURITY_CONTEXT.authentication.principal.username}

spring security 把SPRING_SECURITY_CONTEXT 放入了session 没有直接把username 放进去。下面一段代码主要描述的是session中的存的变量,

存跳转时候的URLsession {SPRING_SECURITY_SAVED_REQUEST_KEY=SavedRequest[​​http://localhost:8080/AVerPortal/resourceAction/resourceIndex.action]​​​}
存的是登录成功时候session中存的信息:

session {SPRING_SECURITY_CONTEXT=org.springframework.security.context.SecurityContextImpl@87b16984: Authentication: org.springframework.security.providers.cas.CasAuthenticationToken@87b16984: Principal: com.avi.casExtends.UserInfo@ff631d80: Username: test; Password: [PROTECTED]; Enabled: true; AccountNonExpired: true; credentialsNonExpired: true; AccountNonLocked: true; Granted Authorities: ROLE_ADMIN; Password: [PROTECTED]; Authenticated: true; Details: org.springframework.security.ui.WebAuthenticationDetails@12afc: RemoteIpAddress: 127.0.0.1; SessionId: AE56E8925195DFF4C50ABD384574CCEA; Granted Authorities: ROLE_ADMIN Assertion: org.jasig.cas.client.validation.AssertionImpl@661a11 Credentials (Service/Proxy Ticket): ST-3-1lX3acgZ6HNgmhvjXuxB-cas, userId=2, userName=test}

在后台获取

UserDetails userDetails = (UserDetails) SecurityContextHolder.getContext()  
.getAuthentication()
.getPrincipal();

userDetails.getUsername()
package com.easykotlin.reakt.controller

import org.springframework.security.core.context.SecurityContextHolder
import org.springframework.security.core.userdetails.UserDetails
import org.springframework.web.bind.annotation.GetMapping
import org.springframework.web.bind.annotation.RequestMapping
import org.springframework.web.bind.annotation.RestController

/**
* Created by Kor on 2017-12-24 14:04:07.
*/
@RestController
@RequestMapping("/user")
class UserController {

@GetMapping(value = ["/currentUser.json"])
fun currentUser(): UserDto {
val UserDto = UserDto()
try {
UserDto.success = true
val loginUser = UserController.UserDto.LoginUser()
val UserDetails = SecurityContextHolder
.getContext()
.authentication
.principal
as UserDetails
loginUser.username = UserDetails.username
UserDto.loginUser = loginUser
} catch (e: Exception) {
UserDto.success = false
UserDto.loginUser = UserController.UserDto.LoginUser()
e.printStackTrace()
}
return UserDto;
}

class UserDto {
var success = false
lateinit var loginUser: LoginUser

class LoginUser {
var username = "NULL"
}
}

}