Spring security 安全框架service层实现

安全框架登录验证
public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
    SysUser sysUser = sysUserDao.findUserByUsername(username);
    if(sysUser!=null){
        Collection<GrantedAuthority> authorities=new ArrayList<>();
        GrantedAuthority grantedAuthority = new SimpleGrantedAuthority("ROLE_USER");
        authorities.add(grantedAuthority);
        UserDetails user =  new User(sysUser.getUsername(),sysUser.getPassword(),authorities);
        return user;
    }
    return null;
}

/**
 * 根据用户在登录窗口登录后从session中提取用户名并获取
 * @return
 */
public String findSession(){
    SecurityContext context = SecurityContextHolder.getContext();
    User sysUser = (User) context.getAuthentication().getPrincipal();
    return sysUser.getUsername();
}