技术要点：springboot的基本知识，redis基本操作，
首先是写一个注解类：
import java.lang.annotation.Retention; import java.lang.annotation.Target; import static java.lang.annotation.ElementType.METHOD; import static java.lang.annotation.RetentionPolicy.RUNTIME; /** * @author yhq */ @Retention(RUNTIME) @Target(METHOD) public @interface AccessLimit { int seconds(); int maxCount(); boolean needLogin()default true; }
接着就是在Interceptor拦截器中实现：
import com.alibaba.fastjson.JSON; import com.example.demo.action.AccessLimit; import com.example.demo.redis.RedisService; import com.example.demo.result.CodeMsg; import com.example.demo.result.Result; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import org.springframework.web.method.HandlerMethod; import org.springframework.web.servlet.handler.HandlerInterceptorAdapter; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.OutputStream; /** * @author yhq */ @Component public class FangshuaInterceptor extends HandlerInterceptorAdapter { @Autowired private RedisService redisService; @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { //判断请求是否属于方法的请求 if(handler instanceof HandlerMethod){ HandlerMethod hm = (HandlerMethod) handler; //获取方法中的注解,看是否有该注解 AccessLimit accessLimit = hm.getMethodAnnotation(AccessLimit.class); if(accessLimit == null){ return true; } int seconds = accessLimit.seconds(); int maxCount = accessLimit.maxCount(); boolean login = accessLimit.needLogin(); String key = request.getRequestURI(); //如果需要登录 if (login){ //获取登录的session进行判断 //..... key+=""+"1"; //这里假设用户是1,项目中是动态获取的userId } //从redis中获取用户访问的次数 AccessKey ak = AccessKey.withExpire(seconds); Integer count = redisService.get(ak,key,Integer.class); if (count == null){ //第一次访问 redisService.set(ak,key,1); } else if (count < maxCount){ //加1 redisService.incr(ak,key); } else { //超出访问次数 render(response,CodeMsg.ACCESS_LIMIT_REACHED); //这里的CodeMsg是一个返回参数 return false; } } return true; } private void render(HttpServletResponse response, CodeMsg cm)throws Exception { response.setContentType("application/json;charset=UTF-8"); OutputStream out = response.getOutputStream(); String str = JSON.toJSONString(Result.error(cm)); out.write(str.getBytes("UTF-8")); out.flush(); out.close(); } }
再把Interceptor注册到springboot中
import com.example.demo.ExceptionHander.FangshuaInterceptor; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Configuration; import org.springframework.web.servlet.config.annotation.InterceptorRegistry; import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter; /** * @author yhq */ @Configuration public class WebConfig extends WebMvcConfigurerAdapter { @Autowired private FangshuaInterceptor interceptor; @Override public void addInterceptors(InterceptorRegistry registry) { registry.addInterceptor(interceptor); } }
接着在Controller中加入注解
import com.example.demo.result.Result; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; /** * @author yhq */ @Controller public class FangshuaController { @AccessLimit(seconds = 5, maxCount = 5, needLogin = true) @RequestMapping("/fangshua") @ResponseBody public Result<String> fangshua() { return Result.success("请求成功"); } }
本文有参考其他视频的教学，希望可以帮助更多热爱it行业的人，
