From 2ee2961731fcc70bfe5965ea4e4a29bb75e948d1 Mon Sep 17 00:00:00 2001
From: YoVinchen <gzh298255@gmail.com>
Date: Thu, 17 Aug 2023 22:29:40 +0800
Subject: [PATCH] =?UTF-8?q?Sentinel=20=E6=95=B4=E5=90=88=E5=AD=A6=E4=B9=A0?=
 =?UTF-8?q?=E5=AE=8C=E6=88=90?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../com/test/controller/BorrowController.java | 26 ++++++++++++-------
 .../test/service/client/UserClientImpl.java   | 21 +++++++++++++++
 .../src/main/resources/application.yml        |  3 +++
 3 files changed, 41 insertions(+), 9 deletions(-)
 create mode 100644 borrow-service/src/main/java/com/test/service/client/UserClientImpl.java

diff --git a/borrow-service/src/main/java/com/test/controller/BorrowController.java b/borrow-service/src/main/java/com/test/controller/BorrowController.java
index f0c5ca5..1fb5027 100644
--- a/borrow-service/src/main/java/com/test/controller/BorrowController.java
+++ b/borrow-service/src/main/java/com/test/controller/BorrowController.java
@@ -1,7 +1,9 @@
 package com.test.controller;
 
 import com.alibaba.csp.sentinel.annotation.SentinelResource;
+import com.alibaba.csp.sentinel.slots.block.BlockException;
 import com.alibaba.fastjson.JSONObject;
+import com.test.entity.User;
 import com.test.entity.UserBorrowDetail;
 import com.test.service.BorrowService;
 import org.springframework.web.bind.annotation.PathVariable;
@@ -10,7 +12,7 @@ import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 import javax.annotation.Resource;
-import java.io.IOException;
+import java.util.Collections;
 
 
 /**
@@ -32,8 +34,15 @@ public class BorrowController {
     }
 
     @RequestMapping("/borrow2/{uid}")
-    UserBorrowDetail findUserBorrows2(@PathVariable("uid") int uid) {
-        return service.getUserBorrowDetailByUid(uid);
+    @SentinelResource(value = "findUserBorrows2", blockHandler = "test")
+    UserBorrowDetail findUserBorrows2(@PathVariable("uid") int uid) throws InterruptedException {
+        throw new RuntimeException();
+    }
+
+    UserBorrowDetail test(int uid, BlockException e) {
+//        输出降级异常
+        System.out.println(e.getClass());
+        return new UserBorrowDetail(new User(), Collections.emptyList());
     }
 
     @RequestMapping("/blocked")
@@ -45,7 +54,7 @@ public class BorrowController {
         return object;
     }
 
-//    @RequestMapping("/test")
+    //    @RequestMapping("/test")
 //    @SentinelResource(value = "test", fallback = "except",    //fallback指定出现异常时的替代方案
 //            blockHandler = "blocked",
 ////            特别注意这种方式会在没有配置blockHandler的情况下，将Sentinel机制内（也就是限流的异常）的异常也一并处理了，如果配置了blockHandler，那么在出现限流时，依然只会执行blockHandler指定的替代方案（因为限流是在方法执行之前进行的）
@@ -60,11 +69,10 @@ public class BorrowController {
 //        return t.getMessage();
 //    }
     @RequestMapping("/test")
-    @SentinelResource("test")   //注意这里需要添加@SentinelResource才可以，用户资源名称就使用这里定义的资源名称
-    String findUserBorrows2(@RequestParam(value = "a", required = false) String a,
-                            @RequestParam(value = "b", required = false) String b,
-                            @RequestParam(value = "c",required = false) String c) {
-        return "请求成功！a = "+a+", b = "+b+", c = "+c;
+    @SentinelResource("test")
+    //注意这里需要添加@SentinelResource才可以，用户资源名称就使用这里定义的资源名称
+    String findUserBorrows2(@RequestParam(value = "a", required = false) String a, @RequestParam(value = "b", required = false) String b, @RequestParam(value = "c", required = false) String c) {
+        return "请求成功！a = " + a + ", b = " + b + ", c = " + c;
     }
 
     //模拟慢调用
diff --git a/borrow-service/src/main/java/com/test/service/client/UserClientImpl.java b/borrow-service/src/main/java/com/test/service/client/UserClientImpl.java
new file mode 100644
index 0000000..6f87680
--- /dev/null
+++ b/borrow-service/src/main/java/com/test/service/client/UserClientImpl.java
@@ -0,0 +1,21 @@
+package com.test.service.client;
+
+import com.test.entity.User;
+import org.springframework.stereotype.Component;
+
+/**
+ * ClassName: UserClientImpl
+ * Package: com.test.service.client
+ *
+ * @author yovinchen
+ * @Create 2023/8/17 22:25
+ */
+@Component
+public class UserClientImpl implements UserClient{
+    @Override
+    public User getUserById(int uid) {
+        User user = new User();
+        user.setName("我是替代方案");
+        return user;
+    }
+}
diff --git a/borrow-service/src/main/resources/application.yml b/borrow-service/src/main/resources/application.yml
index 2dc03f3..4eed866 100644
--- a/borrow-service/src/main/resources/application.yml
+++ b/borrow-service/src/main/resources/application.yml
@@ -28,3 +28,6 @@ spring:
       # 关闭Context收敛，这样被监控方法可以进行不同链路的单独控制
       web-context-unify: false
       block-page: /blocked
+feign:
+  circuitbreaker:
+    enabled: true