SpringBoot integrates Shiro to realize JWT refresh. In which class should refresh token be implemented and how to return a new token (how to get a new token in Controller) to the user when the request is returned?

currently my code is like this: do JWT verification in the login authentication of Realm, but I don"t know how to write it when I judge that the JWT has expired but can still be refreshed. Should I throw an exception to the custom ShiroFilter and redirect a new request or something? Ask the great god for an answer, thank you!

public class MyRealm extends AuthorizingRealm{

    private Logger LOGGER = LoggerFactory.getLogger(this.getClass());
    
    @Resource
    private UserBiz userBiz;
    
    /**
     * Shiro
     */
    @Override
    public boolean supports(AuthenticationToken token) {
        return token instanceof JWTToken;
    }

    
    /**
     * 
     */
    @Override
    protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
        SimpleAuthorizationInfo simpleAuthorizationInfo = new SimpleAuthorizationInfo();
        String token = principals.getPrimaryPrincipal().toString();
        LOGGER.info("Realm:"+token);
        String username = JWTUtil.getUsername(token);
        System.out.println("Realmusername:"+username);
        User user = userBiz.findByName(username);
        
        List<Role> roles = userBiz.selectRoleByUser(user);
        for(Role role : roles){
            simpleAuthorizationInfo.addRole(role.getName());
            List<Permission> permissions = userBiz.selectPermissionByRole(role);
            for(Permission per : permissions){
                simpleAuthorizationInfo.addStringPermission(per.getName());
            }
        }
        
        return simpleAuthorizationInfo;
    }


    /**
     * 
     */
    @Override
    protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken auth) throws TokenExpiredException,AuthenticationException {
        String token = auth.getPrincipal().toString();
        LOGGER.info("Realm:"+token);
        String username = JWTUtil.getUsername(token);
        if(username == null){
            LOGGER.info("tokenusername");
            return null;
        }
        
        User user = userBiz.findByName(username);
        if(user == null){
            return null;
        }
        
        try {
            JWTUtil.verify(token, username, user.getPassword());
        } catch (TokenExpiredException e) {
            //,token,
            LOGGER.info("token");
            if(JWTUtil.verifySignDate(token)){
                LOGGER.info("token,token");
                //token
                return null;
            }
        } catch (Exception e) {
            LOGGER.info("");
            return null;
        }
        
        return new SimpleAuthenticationInfo(token, token, "my_realm");

    }
}