1.Spring Security 目前支持认证一体化如下认证技术：

HTTP BASIC authentication headers (一个基于IEFT  RFC 的标准)
HTTP Digest authentication headers (一个基于IEFT  RFC 的标准)
HTTP X.509 client certificate exchange  (一个基于IEFT RFC 的标准)
LDAP (一个非常常见的跨平台认证需要做法，特别是在大环境)
Form-based authentication (提供简单用户接口的需求)
OpenID authentication
Computer Associates Siteminder
JA-SIG Central Authentication Service  (CAS，这是一个流行的开源单点登录系统)
Transparent authentication context  propagation for Remote Method Invocation and HttpInvoker  (一个Spring远程调用协议)

2.但是有时不想使用这些认证,需要自定义用户认证

    2.1 代码如下:

//从spring容器中获取UserDetailsService(这个从数据库根据用户名查询用户信息,及加载权限的service)
UserDetailsService userDetailsService = 
      (UserDetailsService)SpringContextUtil.getBean("userDetailsService");

//根据用户名username加载userDetails
UserDetails userDetails = userDetailsService.loadUserByUsername(username);

//根据userDetails构建新的Authentication,这里使用了
//PreAuthenticatedAuthenticationToken当然可以用其他token,如UsernamePasswordAuthenticationToken               
PreAuthenticatedAuthenticationToken authentication = 
      new PreAuthenticatedAuthenticationToken(userDetails, userDetails.getPassword(),userDetails.getAuthorities());

//设置authentication中details
authentication.setDetails(new WebAuthenticationDetails(request));

//存放authentication到SecurityContextHolder
SecurityContextHolder.getContext().setAuthentication(authentication);
HttpSession session = request.getSession(true);
//在session中存放security context,方便同一个session中控制用户的其他操作
session.setAttribute("SPRING_SECURITY_CONTEXT", SecurityContextHolder.getContext());

   2.2 方法userDetailsService.loadUserByUsername(username) 如下:

    /**
     * 获取用户Details信息的回调函数.
     */
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException,DataAccessException {
        GeOperator geOperator = geOperatorService.findOperatorByPK(username);
        if(geOperator == null){
            throw new UsernameNotFoundException("","用户名错误");
        }
        //加载该用户权限
        Set<GrantedAuthority> grantedAuths = obtainGrantedAuthorities(geOperator);
        boolean enabled = true;
        boolean accountNonExpired = true;
        boolean credentialsNonExpired = true;
        boolean accountNonLocked = true;

        UserDetails userdetails = new MisUser(username, geOperator.getPwd(), 
                geOperator, enabled, accountNonExpired, credentialsNonExpired, accountNonLocked, grantedAuths);
        
        
        return userdetails;
    }

参考问题:

How to manually set an authenticated user in Spring Security / SpringMVC