From 301eb9d7a22424af952b515d9bbed268952fd9a6 Mon Sep 17 00:00:00 2001
From: Amadeus <RealmeAmadeus@gmail.com>
Date: Sun, 26 May 2024 22:49:18 +0800
Subject: [PATCH] =?UTF-8?q?=E5=AE=9E=E7=8E=B0=E9=99=90=E6=B5=81=E6=93=8D?=
 =?UTF-8?q?=E4=BD=9C?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../com/example/filter/FlowLimitFilter.java   | 62 +++++++++++++++++++
 src/main/java/com/example/utils/Const.java    |  6 +-
 2 files changed, 67 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/com/example/filter/FlowLimitFilter.java

diff --git a/src/main/java/com/example/filter/FlowLimitFilter.java b/src/main/java/com/example/filter/FlowLimitFilter.java
new file mode 100644
index 0000000..39a3b61
--- /dev/null
+++ b/src/main/java/com/example/filter/FlowLimitFilter.java
@@ -0,0 +1,62 @@
+package com.example.filter;
+
+import com.example.entity.RestBean;
+import com.example.utils.Const;
+import jakarta.annotation.Resource;
+import jakarta.servlet.FilterChain;
+import jakarta.servlet.ServletException;
+import jakarta.servlet.http.HttpFilter;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import org.springframework.core.annotation.Order;
+import org.springframework.data.redis.core.StringRedisTemplate;
+import org.springframework.stereotype.Component;
+
+import java.io.IOException;
+import java.util.Optional;
+import java.util.concurrent.TimeUnit;
+
+@Component
+@Order(Const.ORDER_LIMIT)
+public class FlowLimitFilter extends HttpFilter {
+    @Resource
+    StringRedisTemplate template;
+
+    @Override
+    protected void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException {
+        String address = request.getRemoteAddr();
+        if (this.tryCount(address)){
+            chain.doFilter(request,response);
+        }else {
+            this.writeBlockMessage(response);
+        }
+
+    }
+    private void writeBlockMessage(HttpServletResponse response) throws IOException {
+        response.setStatus(HttpServletResponse.SC_FORBIDDEN);
+        response.setContentType("application/json;charset=uft-8");
+        response.getWriter().write(RestBean.forbidden("操作频繁,请稍后再试").asJsonString());
+    }
+    private boolean tryCount(String ip){
+        synchronized (ip.intern()){
+            if (Boolean.TRUE.equals(template.hasKey(Const.FLOW_LIMIT_BLOCK + ip))){
+                return false;
+            }
+            return this.limitPeriodCheck(ip);
+        }
+    }
+    private boolean limitPeriodCheck(String ip){
+        if (Boolean.TRUE.equals(template.hasKey(Const.FLOW_LIMIT_COUNTER + ip))) {
+            long increment = Optional.ofNullable(template.opsForValue().increment(Const.FLOW_LIMIT_COUNTER + ip)).orElse(0L) ;
+            if (increment > 10){
+                template.opsForValue().set(Const.FLOW_LIMIT_BLOCK + ip , "" , 30 ,TimeUnit.SECONDS);
+                return false;
+            }
+
+        }else {
+            template.opsForValue().set(Const.FLOW_LIMIT_COUNTER + ip ,"1" ,3 , TimeUnit.SECONDS );
+        }
+        return true;
+    }
+
+}
diff --git a/src/main/java/com/example/utils/Const.java b/src/main/java/com/example/utils/Const.java
index e60413f..9810230 100644
--- a/src/main/java/com/example/utils/Const.java
+++ b/src/main/java/com/example/utils/Const.java
@@ -5,7 +5,11 @@ public class Const {
 
     public static final String VERIFY_EMAIL_LIMIT = "verify:email:limit:";
     public static final String VERIFY_EMAIL_DATA = "verify:email:data:";
-
     public static final int ORDER_CORS = -102;
+    public static final int ORDER_LIMIT = -101;
+
+    public static final String FLOW_LIMIT_COUNTER= "flow:counter:";
+    public static final String FLOW_LIMIT_BLOCK= "flow:block:";
+
 
 }