FeignClient的fallbackFactory属性

Author: enjoyCoding666

eureka-client/pom.xml

@@ -53,6 +53,17 @@
         </dependency>
 
 
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>com.alibaba</groupId>
+            <artifactId>fastjson</artifactId>
+            <version>1.2.54</version>
+        </dependency>
+
     </dependencies>
 
     <dependencyManagement>

eureka-client/src/main/java/com/example/demo/controller/UserController.java

@@ -1,17 +1,23 @@
 package com.example.demo.controller;
 
-import org.springframework.web.bind.annotation.GetMapping;
-import org.springframework.web.bind.annotation.RestController;
+import com.alibaba.fastjson.JSONObject;
+import com.example.demo.pojo.User;
+import org.springframework.web.bind.annotation.*;
 
 @RestController
 public class UserController {
 
-        @GetMapping("/user/name")
-        public void getUserName( ) throws Exception {
-            System.out.println("==================================================================>getUserName( )");
-            throw  new Exception("getUserNameException");
+        @PostMapping("/user/name/{id}")
+        public JSONObject getUserNameById(@PathVariable("id") Integer id ) throws Exception {
+            System.out.println("==================================================================>getUserNameById()，id为："+id);
+            //直接抛异常，是为了测试服务熔断和降级。
+            throw  new Exception("getUserNameByIdException");
         }
 
-
+       @PostMapping("/user")
+       public User getUserById(@RequestParam("id") Integer id  ) throws Exception {
+         System.out.println("==================================================================>getUserById(),id为："+id);
+         throw  new Exception("getUserByIdException");
+      }
 
 }

eureka-client/src/main/java/com/example/demo/pojo/User.java

@@ -0,0 +1,17 @@
+package com.example.demo.pojo;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+@Builder
+public class User {
+    private Integer id;
+    private String name;
+
+
+}

eureka-consumer-feign/pom.xml

@@ -52,8 +52,16 @@
             <groupId>org.projectlombok</groupId>
             <artifactId>lombok</artifactId>
         </dependency>
+
+        <dependency>
+            <groupId>com.alibaba</groupId>
+            <artifactId>fastjson</artifactId>
+            <version>1.2.54</version>
+        </dependency>
     </dependencies>
 
+
+
     <!--指定springCloud版本-->
     <dependencyManagement>
         <dependencies>

eureka-consumer-feign/src/main/java/com/example/demo/controller/DcController.java renamed to eureka-consumer-feign/src/main/java/com/example/demo/controller/ConsumerDcController.java

@@ -9,7 +9,7 @@
  * Created by lenovo on  九月
  */
 @RestController
-public class DcController {
+public class ConsumerDcController {
 
     @Autowired
     private DcClient dcClient;

eureka-consumer-feign/src/main/java/com/example/demo/controller/ConsumerUserController.java

@@ -0,0 +1,26 @@
+package com.example.demo.controller;
+
+import com.alibaba.fastjson.JSONObject;
+import com.example.demo.feignInterface.user.UserFeignClient;
+import com.example.demo.pojo.User;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.*;
+
+@RestController
+public class ConsumerUserController {
+
+    @Autowired
+    private UserFeignClient userFeignClient;
+
+    @PostMapping("/consumer/user/name/{id}")
+    public JSONObject getUserName(@PathVariable("id") Integer id){
+        return userFeignClient.getUserNameById(id);
+    }
+
+    @PostMapping("/consumer/user")
+    public User getUser(@RequestParam("id") Integer id){
+        return userFeignClient.getUserById(id);
+    }
+}
+
+

eureka-consumer-feign/src/main/java/com/example/demo/controller/UserController.java

@@ -11,8 +11,7 @@
  * 使用@FeignClient注解。其中的value指定这个接口所要调用的服务名称，fallback指定hystrix的回调类
  * 接口中定义的各个函数使用Spring MVC的注解就可以来绑定服务提供方的REST接口
  */
-//@FeignClient(value = "eureka-client",fallback = ClientHystrix.class)
-@FeignClient(value = "eureka-client",fallbackFactory = ClientHystrixFallbackFactory.class)
+@FeignClient(value = "eureka-client",fallback = ClientHystrix.class)
 public interface DcClient {
      @GetMapping(value = "/dc")
      String consumer();

eureka-consumer-feign/src/main/java/com/example/demo/feignInterface/dc/ClientHystrixFallbackFactory.java

@@ -1,15 +1,36 @@
 package com.example.demo.feignInterface.user;
 
+import com.alibaba.fastjson.JSONObject;
+import com.example.demo.pojo.User;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Component;
 
 @Component
-@Slf4j
 public class UserClientFallbackFactory implements UserFeignClient {
 
+    /**
+     * 服务熔断
+     * @param id
+     * @return
+     */
     @Override
-    public String getUserName() {
-        log.debug("=======================>UserClientFallbackFactoryTest");
-        return "UserClientFallbackFactoryTest";
+    public JSONObject getUserNameById(Integer id) {
+        System.out.println("=======================>UserClientFallbackFactoryTest");
+        JSONObject resultJson = new JSONObject();
+        resultJson.put("errCode",  "0404" );
+        String description="查询id为"+id+"的用户，服务异常，暂时熔断";
+        resultJson.put("description", description  );
+        return resultJson;
     }
+
+
+    @Override
+    public User getUserById(Integer id) {
+        System.out.println("=======================>UserClientFallbackFactoryTest");
+         //直接返回id为-1的用户
+        User user = new User();
+        user.setId(-1);
+        return user;
+     }
+
 }

eureka-consumer-feign/src/main/java/com/example/demo/feignInterface/dc/DcClient.java

@@ -1,7 +1,11 @@
 package com.example.demo.feignInterface.user;
 
+import com.alibaba.fastjson.JSONObject;
+import com.example.demo.pojo.User;
 import org.springframework.cloud.netflix.feign.FeignClient;
-import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestParam;
 
 
 /**
@@ -10,6 +14,9 @@
 @FeignClient(value = "eureka-client",fallbackFactory = UserHystrixFallbackFactory.class)
 public interface UserFeignClient {
 
-    @GetMapping(value = "/user/name")
-    String getUserName();
+    @PostMapping(value = "/user/name/{id}")
+    JSONObject getUserNameById(@PathVariable("id") Integer id);
+
+    @PostMapping(value = "/user")
+    User getUserById(@RequestParam("id") Integer id);
 }

eureka-consumer-feign/src/main/java/com/example/demo/feignInterface/dc/DcClientFallbackFactory.java

@@ -13,14 +13,17 @@ public class UserHystrixFallbackFactory  implements FallbackFactory<UserFeignCli
 
     @Override
     public UserFeignClient create(Throwable cause) {
-        log.info("fallback reason was: {} ", cause.getMessage());
+        System.out.println("====================================》fallback reason was:  " + cause.getMessage());
 
         return new UserClientFallbackFactory();
-        //也可以不写UserClientFallbackFactory类，直接写成以下形式：
-//        return new UserFeignClient() {
+        //也可以不写UserClientFallbackFactory类，直接用匿名对象写成以下形式：
+//        return new UserFeignClient(Integer id) {
 //            @Override
-//            public String getUserName() {
-//                return "降级信息";
+//            public JSONObject getUserNameById() {
+//                 JSONObject resultJson = new JSONObject();
+//                 resultJson.put("id",  "-1" );
+//                 resultJson.put("name", "null"   );
+//                 return resultJson;
 //            }
 //        };