服务消费者使用 OpenFeign 实现服务调用

README.md

@@ -11,7 +11,7 @@ Spring Cloud & Spring Cloud Alibaba Learning Project
         - nacos-discovery-provider-sample           // Nacos Discovery Provider Sample
             - 掌握 Nacos Discovery 实现 Spring Cloud 服务注册和发现
         - nacos-discovery-consumer-sample           // Nacos Discovery Consumer Sample
-            - Nacos Discovery 整合 @LoadBalanced RestTemplate 以及 Open Feign
+            - Nacos Discovery 整合 @LoadBalanced RestTemplate 以及 Open Feign 服务调用
         - .gitignore
         - README.md
 

nacos-discovery-consumer-sample/src/main/java/com/example/demo/NacosDiscoveryConsumerSampleApplication.java

@@ -3,9 +3,11 @@
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
+import org.springframework.cloud.openfeign.EnableFeignClients;
 
 @SpringBootApplication
 @EnableDiscoveryClient
+@EnableFeignClients // 激活 @FeignClient
 public class NacosDiscoveryConsumerSampleApplication {
 
     public static void main(String[] args) {

nacos-discovery-consumer-sample/src/main/java/com/example/demo/controller/OpenFeignController.java

@@ -0,0 +1,25 @@
+package com.example.demo.controller;
+
+import com.example.demo.service.EchoService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RestController;
+
+/**
+ * OpenFeign 服务调用
+ *
+ * @author yclimb
+ * @date 2020/9/30
+ */
+@RestController
+public class OpenFeignController {
+
+    @Autowired
+    private EchoService echoService;
+
+    @GetMapping("/feign/echo/{message}")
+    public String feignEcho(@PathVariable String message) {
+        return echoService.echo(message);
+    }
+}

nacos-discovery-consumer-sample/src/main/java/com/example/demo/RestTemplateController.java → nacos-discovery-consumer-sample/src/main/java/com/example/demo/controller/RestTemplateController.java

@@ -1,4 +1,4 @@
-package com.example.demo;
+package com.example.demo.controller;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.cloud.client.loadbalancer.LoadBalanced;
@@ -9,7 +9,7 @@
 import org.springframework.web.client.RestTemplate;
 
 /**
- * 服务调用
+ * LoadBalanced 服务调用
  *
  * @author yclimb
  * @date 2020/9/30

nacos-discovery-consumer-sample/src/main/java/com/example/demo/service/EchoService.java

@@ -0,0 +1,26 @@
+package com.example.demo.service;
+
+import org.springframework.cloud.openfeign.FeignClient;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+
+/**
+ * 指向服务提供者应用
+ *
+ * @author yclimb
+ * @date 2020/9/30
+ */
+@FeignClient("nacos-discovery-provider-sample")
+public interface EchoService {
+
+    /**
+     * echo(String) 方法在 Spring MVC 请求映射的方式与 nacos-discovery-provider-sample 中的 ServiceController 基本相同，
+     * 唯一区别在于 @PathVariable 注解指定了 value 属性 “message”，
+     * 这是因为默认情况，Java 编译器不会讲接口方法参数名添加到 Java 字节码中。
+     *
+     * @param message message
+     * @return String
+     */
+    @GetMapping("/echo/{message}")
+    String echo(@PathVariable("message") String message);
+}

nacos-discovery-provider-sample/src/main/java/com/example/demo/ServiceController.java → nacos-discovery-provider-sample/src/main/java/com/example/demo/controller/ServiceController.java

@@ -1,4 +1,4 @@
-package com.example.demo;
+package com.example.demo.controller;
 
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;