1.3. 构建您的 booster 项目

流程

1. 打开 shell 提示符并使用 Maven 从命令行构建项目：

   cd fuse-circuit-breaker

   mvn clean package

   Maven 构建项目后，它会显示 Build Success 消息。

2. 打开一个新的 shell 提示符并启动名称服务，如下所示：

   cd name-service

   mvn spring-boot:run -DskipTests -Dserver.port=8081

   当 Spring Boot 启动时，您应该看到类似如下的输出：

   ...
   2019-05-06 20:19:59.401  INFO 9553 --- [           main] o.a.camel.spring.SpringCamelContext      : Route: route1 started and consuming from: servlet:/name?httpMethodRestrict=GET
   2019-05-06 20:19:59.402  INFO 9553 --- [           main] o.a.camel.spring.SpringCamelContext      : Total 1 routes, of which 1 are started
   2019-05-06 20:19:59.403  INFO 9553 --- [           main] o.a.camel.spring.SpringCamelContext      : Apache Camel 2.21.0.fuse-730078-redhat-00001 (CamelContext: camel-1) started in 0.287 seconds
   2019-05-06 20:19:59.406  INFO 9553 --- [           main] o.a.c.c.s.CamelHttpTransportServlet      : Initialized CamelHttpTransportServlet[name=CamelServlet, contextPath=]
   2019-05-06 20:19:59.473  INFO 9553 --- [           main] b.c.e.u.UndertowEmbeddedServletContainer : Undertow started on port(s) 8081 (http)
   2019-05-06 20:19:59.479  INFO 9553 --- [           main] com.redhat.fuse.boosters.cb.Application  : Started Application in 5.485 seconds (JVM running for 9.841)

3. 打开一个新的 shell 提示符并启动问候服务，如下所示：

   cd greetings-service

   mvn spring-boot:run -DskipTests

   当 Spring Boot 启动时，您应该看到类似如下的输出：

   ...
   2019-05-06 20:22:19.051  INFO 9729 --- [           main] o.a.c.c.s.CamelHttpTransportServlet      : Initialized CamelHttpTransportServlet[name=CamelServlet, contextPath=]
   2019-05-06 20:22:19.115  INFO 9729 --- [           main] b.c.e.u.UndertowEmbeddedServletContainer : Undertow started on port(s) 8080 (http)
   2019-05-06 20:22:19.123  INFO 9729 --- [           main] com.redhat.fuse.boosters.cb.Application  : Started Application in 7.68 seconds (JVM running for 12.66)

   greetings 服务通过 http://localhost:8080/camel/greetings URL 公开 REST 端点。

4. 通过在 web 浏览器中打开 URL 或打开另一个 shell 提示符并输入以下 curl 命令来调用 REST 端点：

   curl http://localhost:8080/camel/greetings

   以下是响应：

   {"greetings":"Hello, Jacopo"}

5. 要演示 Camel Hystrix 提供的断路器功能，请在名称服务的 shell 提示符窗口中键入 Ctrl-C 来终止后端名称服务。

   现在，名称服务不可用，断路器在 中启动，以防止在调用时问候服务挂起。

6. 在网页浏览器中打开 http://localhost:8080/camel/greetings，或者在另一个 shell 提示符窗口中输入以下 curl 命令来调用问候 REST 端点：

   curl http://localhost:8080/camel/greetings

   以下是响应：

   {"greetings":"Hello, default fallback"}

   在运行 greetings 服务的窗口中，日志会显示以下信息序列：

   2019-05-06 20:24:16.952  INFO 9729 --- [-CamelHystrix-2] route2                                   :  Try to call name Service
   2019-05-06 20:24:16.956  INFO 9729 --- [-CamelHystrix-2] o.a.c.httpclient.HttpMethodDirector      : I/O exception (java.net.ConnectException) caught when processing request: Connection refused (Connection refused)
   2019-05-06 20:24:16.956  INFO 9729 --- [-CamelHystrix-2] o.a.c.httpclient.HttpMethodDirector      : Retrying request
   2019-05-06 20:24:16.957  INFO 9729 --- [-CamelHystrix-2] o.a.c.httpclient.HttpMethodDirector      : I/O exception (java.net.ConnectException) caught when processing request: Connection refused (Connection refused)
   2019-05-06 20:24:16.957  INFO 9729 --- [-CamelHystrix-2] o.a.c.httpclient.HttpMethodDirector      : Retrying request
   2019-05-06 20:24:16.957  INFO 9729 --- [-CamelHystrix-2] o.a.c.httpclient.HttpMethodDirector      : I/O exception (java.net.ConnectException) caught when processing request: Connection refused (Connection refused)
   2019-05-06 20:24:16.957  INFO 9729 --- [-CamelHystrix-2] o.a.c.httpclient.HttpMethodDirector      : Retrying request
   2019-05-06 20:24:16.964  INFO 9729 --- [-CamelHystrix-2] route2                                   :  We are falling back!!!!

7. 有关此示例的更多信息，请打开 Circuit Breaker - Red Hat Fuse 页面，地址为 http://localhost:8080/ （同时 问候服务正在运行 ）。此页面包含一个到监控断路器状态的 Hystrix 仪表板的链接。