Dubbo 2.6.x使用

环境

代码地址dubbo-v2.6.x

• dubbo 2.6.5
• dubbo-spring-boot-starter 0.2.0

由于 dubbo-2.6.5 及以下版本的 Reference 还不支持 protocol 属性（dubbo-2.7.0支持了），注解暂时无法指定协议，但是可以使用xml配置指定协议

启动 provider 端

访问以下地址来判断provider端使用多协议是否正常

http://localhost:9090/demo/echo?message=rest协议

启动 consumer 端

分别访问以下地址来判断consumer端使用多协议是否正常

• http://localhost:8080/demo/dubbo?message=使用dubbo协议
• http://localhost:8080/demo/rest?message=使用rest协议

提示 AnnotationInjectedBeanPostProcessor 异常

issue

Caused by: java.lang.ClassNotFoundException: com.alibaba.spring.beans.factory.annotation.AnnotationInjectedBeanPostProcessor

解决，添加以下依赖

<dependency>
    <groupId>com.alibaba.spring</groupId>
    <artifactId>spring-context-support</artifactId>
    <version>1.0.2</version>
</dependency>

异常问题

• java.lang.NoClassDefFoundError: org/jboss/resteasy/client/jaxrs/engines/ApacheHttpClient4Engine

需要添加以下依赖包，该依赖 provider 端无需依赖，consumer 端需要依赖

<dependency>
    <groupId>org.jboss.resteasy</groupId>
    <artifactId>resteasy-client</artifactId>
    <version>${resteasy-client.version}</version>
</dependency>

• java.lang.RuntimeException: You must use at least one, but no more than one http method annotation on: top.ylonline.dubbo.spring.boot.example.api.EchoService.echo..

出现这个异常，说明要在使用的接口标注：@Path、@POST、@Get等javax.ws.rs.*这个路径下相关注解，不应该在实现类标注

package top.ylonline.dubbo.spring.boot.example.api;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.QueryParam;

/**
 * @author YL
 */
@Path("/demo")
public interface EchoService {
    /**
     * echo
     *
     * @param message msg
     *
     * @return 信息
     */
    @GET
    @Path("/echo")
    String echo(@QueryParam("message") String message);
}

dubbo-spring-boot-starter 中 spring-boot-starter scope 传递问题

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
</dependency>

<dependency>
    <groupId>com.alibaba.boot</groupId>
    <artifactId>dubbo-spring-boot-starter</artifactId>
    <version>0.2.0</version>
</dependency>

由于dubbo-spring-boot-starter中依赖了spring-boot-starter的scope是true，会导致其继承spring-boot-starter-test的scope，使其变成test

<!-- Spring Boot dependencies -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter</artifactId>
    <scope>true</scope>
</dependency>

spring 版本不一致问题

• 项目中 pom.xml

  <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>2.0.6.RELEASE</version>
      <relativePath/>
  </parent>
  
  <properties>
      <dubbo.version>2.6.5</dubbo.version>
  </properties>
  
  <dependencyManagement>
      <dependencies>
          <dependency>
              <groupId>com.alibaba</groupId>
              <artifactId>dubbo-dependencies-bom</artifactId>
              <version>${dubbo.version}</version>
              <type>pom</type>
              <scope>import</scope>
          </dependency>
      </dependencies>
  </dependencyManagement>

• dubbo-dependencies-bom pom.xml

  <properties>
      <!-- Common libs -->
      <spring_version>4.3.16.RELEASE</spring_version>
  </properties>
  
  <dependencyManagement>
      <dependencies>
          <!-- Common libs -->
          <dependency>
              <groupId>org.springframework</groupId>
              <artifactId>spring-framework-bom</artifactId>
              <version>${spring_version}</version>
              <type>pom</type>
              <scope>import</scope>
          </dependency>
      </dependencies>
  </dependencyManagement>

由于spring-boot-starter-parent中的依赖的spring版本是5.0.10 .RELEASE，dubbo-dependencies-bom中依赖了spring-framework-bom，版本是4.3.16 .RELEASE，会导致spring的版本不一致问题

解决方法：将dubbo-dependencies-bom作为parent，spring-boot-starter-parent放到dependencyManagement中，但是如果这样的话，有可能引发其他依赖问题