单体应用限流学习笔记

1. 添加依赖

   <dependency>
       <groupId>com.google.guava</groupId>
       <artifactId>guava</artifactId>
   </dependency>
   

2. 编写限流Filter业务

   @Component
   public class RateLimitFilter extends OncePerRequestFilter {
         
         
       private RateLimiter rateLimiter =  RateLimiter.create(1) ;
       @Override
       protected void doFilterInternal(HttpServletRequest request,
           HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
         
         
           if (rateLimiter.tryAcquire()){
         
         
               filterChain.doFilter(request, response);
               return;
           }
           response.setStatus(HttpStatus.TOO_MANY_REQUESTS.value());
           response.getWriter().write("too many request !!!");
           response.getWriter().flush();
       }
   }
   

3. 编写Controller测试

   @RestController
   public class RateLimitController {
         
         
       @GetMapping("/limit")
       public String limit(){
         
         
           return "success" ;
       }
   }