自定义注解，aop+redis，实现controller接口频率

1，环境配置

1. 引入aop的jar包
   compile 'org.springframework:spring-aop:3.2.4.RELEASE' 版本号同项目中的一致即可
   2）使用xml配置
   applicationContext.xml，项目配置文件中开启aop支持。 <aop:aspectj-autoproxy/>
dispatcherServletContext.xml，spring的配置文件中开启aop支持。 <aop:aspectj-autoproxy/>
   使用java config配置
   WebConfig类以及AppConfig类中，使用注解 @EnableAspectJAutoProxy
2. 配置扫描的包
   xml方式
   <context:component-scan base-package="com.hzq"> <context:include-filter type="annotation" expression="org.springframework.stereotype.Component"/> </context:component-scan>
   java config方式
   @ComponentScan(basePackages = "com.hzq" includeFilters = {@ComponentScan.Filter(Controller.class), @ComponentScan.Filter(ControllerAdvice.class)})

2，自定义注解

/**
 * Created by hzq on 2017/5/24.
 */
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
@Documented
@Order(Ordered.HIGHEST_PRECEDENCE)
public @interface RequestLimit {

    /**
     * 调用的次数
     * @return
     */
    int count() default Integer.MAX_VALUE;

    /**
     * 时间段； 在time内调用的次数count
     * @return
     */
    int time() default 60000;

}

3，切面通知实现类。使用@Around的方式。可以在调用方法前后，执行一些操作。

AOP概念相关的可参考：http://www.cnblogs.com/shipengzhi/articles/2716004.html

通知（Advice） ：定义了切面是什么以及何时使用。描述了切面要完成的工作和何时需要执行这个工作。eg环绕通知：@Around
切入点（Pointcut） ：例如某个类或方法的名称。eg:within(@org.springframework.stereotype.Controller *) && @annotation(limit)"//所有的controller中，含有@RequestLimit注解的方法作为切点。
连接点（Joinpoint） ：例如方法被调用时、异常被抛出时等等。
目标对象（Target Object） ：即被通知的对象。eg:joinPoint.getTarget()
切面（Aspect） ：通知+切入点=切面。

/**
 * Created by hzq on 2017/5/24.
 */
@Aspect
@Component
public class RequestLimitContract {

    private static Logger logger = LoggerFactory.getLogger(RequestLimitContract.class);

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @Around("within(@org.springframework.stereotype.Controller *) && @annotation(limit)")
    public Object requestLimit(final ProceedingJoinPoint joinPoint, RequestLimit limit){
        Map<String, Object> map = Maps.newHashMap();

        try {
            Object[] args = joinPoint.getArgs();
            HttpServletRequest request = null;
            for(int i = 0; i < args.length; i++){
                if(args[i] instanceof HttpServletRequest){
                    request = (HttpServletRequest) args[i];
                    break;
                }
            }

            if(request == null){
                throw new RuntimeException("request is valid");
            }

            String ip = NginxUtils.getRealIp(request);
            String url = request.getRequestURI();
            String key = "req_limit_" + url + "_" + ip;
            BoundValueOperations<String, String> ops = stringRedisTemplate.boundValueOps(key);

            String countString = ops.get();
            if(countString == null || countString.equals("")){
                logger.info("ip:" + ip + ", first request within 1s");
                ops.set("0", limit.time(), TimeUnit.MILLISECONDS);
            }

            long count;
            try {
                count = Long.valueOf(ops.get());
            } catch (Throwable t){
                count = 0;
            }

            if(count > limit.count()){
                logger.info("url:\t" + url + ",  ip:\t" + ip + " limit request");
                map.put("success", false);
                map.put("message", "the ip: " + ip + " is up to the limit " + limit.count() + " within " + limit.time()/1000 + "s");

                return map;
            }

            Long milSeconds = stringRedisTemplate.getExpire(key, TimeUnit.MILLISECONDS);
            if(milSeconds == null || milSeconds <= 0){
                ops.set("0", limit.time(), TimeUnit.MILLISECONDS);
            }

            ops.increment(1);
            if(milSeconds != null && milSeconds > 0){
                ops.expire(milSeconds, TimeUnit.MILLISECONDS);
            }

            return joinPoint.proceed();
        } catch (Throwable t){
            logger.info(t.getMessage(), t);
            throw new RuntimeException(t.getMessage());
        }
    }

}

4，使用注解。

    @RequestMapping(value = "/api/info", method = RequestMethod.POST)
    @ResponseBody
    @RequestLimit(count = 10, time = 1000)
    public Map<String, Object> getApiInfo(HttpServletRequest request){
        Map<String, Object> map = Maps.newHashMap();
        try {
            //service
            map.put("success", true);
            map.put("info", uidAndRoleList);
        } catch(Throwable t){
            logger.info(t.getMessage(), t);
            map.put("success", false);
            map.put("message", t.getMessage());
        }

        return map;
    }

5，使用拦截器的方式

@Component
public class RequestLimitInterceptor implements HandlerInterceptor{

    private static Logger logger = LoggerFactory.getLogger(RequestLimitInterceptor.class);

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @Value("${request.limit.count}")
    private String limitCount;

    @Value("${request.limit.time}")
    private String limitTime;

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        try {
            if(request == null){
                throw new RuntimeException("request is valid");
            }

            String ip = request.getRemoteAddr();
            String url = request.getRequestURI();
            String key = "req_limit_" + url + "_" + ip;
            long count = stringRedisTemplate.boundValueOps(key).increment(1);
            if(count == 1){
                stringRedisTemplate.boundValueOps(key).expire(Integer.valueOf(limitTime), TimeUnit.MILLISECONDS);
            }

            if(count > Integer.valueOf(limitCount)){
                logger.info("url:\t" + url + ",  ip:\t" + ip + " limit request");
                throw new RuntimeException("the ip:\t" + ip + " is up to the limit " + limitCount + " within " + Integer.valueOf(limitTime)/1000 + " s");
            }
        } catch (Throwable t){
            logger.info(t.getMessage(), t);
            throw new RuntimeException(t.getMessage());
        }

        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }
}