How to check “hasRole” in Java Code with Spring Security?

Question

How to check user authority or permission in Java Code ? For example - I want to show or hide button for user depending on role. There are annotations like:

Answer 1

You can implement a hasRole() method as below - (This is tested on spring security 3.0.x not sure about other versions.)

  protected final boolean hasRole(String role) {
    boolean hasRole = false;
    UserDetails userDetails = getUserDetails();
    if (userDetails != null) {
      Collection authorities = userDetails.getAuthorities();
      if (isRolePresent(authorities, role)) {
        hasRole = true;
      }
    } 
    return hasRole;
  }
  /**
   * Get info about currently logged in user
   * @return UserDetails if found in the context, null otherwise
   */
  protected UserDetails getUserDetails() {
    Object principal = SecurityContextHolder.getContext().getAuthentication().getPrincipal();
    UserDetails userDetails = null;
    if (principal instanceof UserDetails) {
      userDetails = (UserDetails) principal;
    }
    return userDetails;
  }
  /**
   * Check if a role is present in the authorities of current user
   * @param authorities all authorities assigned to current user
   * @param role required authority
   * @return true if role is present in list of authorities assigned to current user, false otherwise
   */
  private boolean isRolePresent(Collection authorities, String role) {
    boolean isRolePresent = false;
    for (GrantedAuthority grantedAuthority : authorities) {
      isRolePresent = grantedAuthority.getAuthority().equals(role);
      if (isRolePresent) break;
    }
    return isRolePresent;
  }