增加 Hystrix 入门示例

labx-23/labx-23-scn-hystrix-demo01/pom.xml

@@ -9,9 +9,11 @@
     </parent>
     <modelVersion>4.0.0</modelVersion>
 
-    <artifactId>labx-22-scn-hystrix-demo01</artifactId>
+    <artifactId>labx-23-scn-hystrix-demo01</artifactId>
 
     <properties>
+        <maven.compiler.target>1.8</maven.compiler.target>
+        <maven.compiler.source>1.8</maven.compiler.source>
         <spring.boot.version>2.2.4.RELEASE</spring.boot.version>
         <spring.cloud.version>Hoxton.SR1</spring.cloud.version>
     </properties>

labx-23/labx-23-scn-hystrix-demo01/src/main/java/cn/iocoder/springcloud/labx23/hystrixdemo/controller/CacheDemoController.java

@@ -0,0 +1,33 @@
+package cn.iocoder.springcloud.labx23.hystrixdemo.controller;
+
+import cn.iocoder.springcloud.labx23.hystrixdemo.service.CacheDemoService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/cache-demo")
+public class CacheDemoController {
+
+    @Autowired
+    private CacheDemoService cacheDemoService;
+
+    @GetMapping("/get_user")
+    public String getUser(@RequestParam("id") Integer id) {
+        String userA = cacheDemoService.getUser(id);
+        String userB = cacheDemoService.getUser(id);
+        String userC = cacheDemoService.getUser(id);
+        return userC;
+    }
+
+    @GetMapping("/update_user")
+    public String updateUser(@RequestParam("id") Integer id) {
+        String userA = cacheDemoService.getUser(id);
+        cacheDemoService.updateUser(id);
+        String userC = cacheDemoService.getUser(id);
+        return userC;
+    }
+
+}

labx-23/labx-23-scn-hystrix-demo01/src/main/java/cn/iocoder/springcloud/labx23/hystrixdemo/filter/HystrixRequestContextFilter.java

@@ -0,0 +1,28 @@
+package cn.iocoder.springcloud.labx23.hystrixdemo.filter;
+
+import com.netflix.hystrix.strategy.concurrency.HystrixRequestContext;
+import org.springframework.stereotype.Component;
+
+import javax.servlet.*;
+import javax.servlet.annotation.WebFilter;
+import java.io.IOException;
+
+@Component
+@WebFilter(urlPatterns = "/")
+public class HystrixRequestContextFilter implements Filter {
+
+    @Override
+    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
+            throws IOException, ServletException {
+        // 初始化 HystrixRequestContext
+        HystrixRequestContext context = HystrixRequestContext.initializeContext();
+        // 继续过滤器
+        try {
+            chain.doFilter(request, response);
+        } finally {
+            // 销毁 HystrixRequestContext
+            context.close();
+        }
+    }
+
+}

labx-23/labx-23-scn-hystrix-demo01/src/main/java/cn/iocoder/springcloud/labx23/hystrixdemo/service/CacheDemoService.java

@@ -0,0 +1,43 @@
+package cn.iocoder.springcloud.labx23.hystrixdemo.service;
+
+import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
+import com.netflix.hystrix.contrib.javanica.cache.annotation.CacheRemove;
+import com.netflix.hystrix.contrib.javanica.cache.annotation.CacheResult;
+import org.apache.commons.lang.exception.ExceptionUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+import org.springframework.web.client.RestTemplate;
+
+@Service
+public class CacheDemoService {
+
+    private Logger logger = LoggerFactory.getLogger(CacheDemoService.class);
+
+    @Autowired
+    private RestTemplate restTemplate;
+
+    @HystrixCommand(fallbackMethod = "getUserFallback")
+    @CacheResult(cacheKeyMethod = "genGetUserCacheKey")
+    public String getUser(Integer id) {
+        logger.info("[getUser][准备调用 user-service 获取用户({})详情]", id);
+        return restTemplate.getForEntity("http://127.0.0.1:18080/user/get?id=" + id, String.class).getBody();
+    }
+
+    @HystrixCommand
+    @CacheRemove(commandKey = "getUser", cacheKeyMethod = "genGetUserCacheKey")
+    public void updateUser(Integer id) {
+        logger.info("[updateUser][更新用户({})详情]", id);
+    }
+
+    public String getUserFallback(Integer id, Throwable throwable) {
+        logger.info("[getUserFallback][id({}) exception({})]", id, ExceptionUtils.getRootCauseMessage(throwable));
+        return "mock:User:" + id;
+    }
+
+    public String genGetUserCacheKey(Integer id) {
+        return "USER_" + id;
+    }
+
+}

labx-23/labx-23-user-service/pom.xml

@@ -9,9 +9,10 @@
     </parent>
     <modelVersion>4.0.0</modelVersion>
 
-    <artifactId>labx-22-user-service</artifactId>
+    <artifactId>labx-23-user-service</artifactId>
 
     <properties>
+        <java.version>1.8</java.version>
         <spring.boot.version>2.2.4.RELEASE</spring.boot.version>
         <spring.cloud.version>Hoxton.SR1</spring.cloud.version>
     </properties>

labx-23/pom.xml

@@ -12,8 +12,8 @@
     <artifactId>labx-23</artifactId>
     <packaging>pom</packaging>
     <modules>
-        <module>labx-22-scn-hystrix-demo01</module>
-        <module>labx-22-user-service</module>
+        <module>labx-23-scn-hystrix-demo01</module>
+        <module>labx-23-user-service</module>
     </modules>