详解SpringBoot如何优雅的处理免登录接口

import java.lang.annotation.*;
 
/**
 * 不校验token注解
 */
@Target({ElementType.METHOD,ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface NoToken {
    String name() default "";
}

@Slf4j
public class SessionInterceptor implements HandlerInterceptor {
 
    //在请求处理之前进行调用Controller方法调用之前
    @Override
    @Reference
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
 
        if (handler instanceof HandlerMethod) {
            HandlerMethod handlerMethod = (HandlerMethod) handler;
            NoToken classAnno = handlerMethod.getMethod().getDeclaringClass().getAnnotation(NoToken.class);
            //获取出Controller上的NoToken注解
            if (classAnno != null) {
                // 如果注解不为null, 说明不需要拦截, 直接放过
                return true;
            } else {
                Method method = handlerMethod.getMethod();
                handlerMethod.getMethodAnnotation(NoToken.class);
                //获取出方法上的NoToken注解
                NoToken access = method.getAnnotation(NoToken.class);
                if (access != null) {
                    // 如果注解不为null, 说明不需要拦截, 直接放过
                    return true;
                }
            }
        }
 
        RedisService redis = (RedisService) SpringContextUtils.getBean("redisService");
        String token = request.getHeader("token");
 
 
        boolean ok = false;
        log.info("开始检验token!");
        if (!StringUtils.isEmpty(token)) {
            if (redis.exists(token)) {
                redis.expire(token, ConstantsUtil.APP_TOKEN_EXPIRE);
                log.info("token有效!");
                ok = true;
            }
        }
 
 
        if (!ok) {
            Map<String, Object> result = new HashMap<>();
            result.put("returncode","-1");
            result.put("returnmsg", "登录已过期,请重新登录");
            writeJSON(response, result);
            return ok;
        }
        return ok;
 
    }
 
    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
    }
 
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception e) throws Exception {
 
    }
    public void writeJSON(HttpServletResponse response, Object o)
            throws IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        String JsonString = JSON.toJSONString(o);
        out.write(JsonString);
    }
}

/**
 * 类上加NoToken注解，该类下所有方法都免登录
 */
@NoToken
@Slf4j
@RestController
@RequestMapping("/test")
public class TestController {
 
 
    /**
     * 方法上单独加注解，只对该方法免登录
     */
    @NoToken
    @RequestMapping("testMethod")
    public void testMethod() {
        System.out.println("1111111111111");
    }
 
 
}