微服務：dubbo 從2.6 升級到2.7

dubbo 從2.6 升級到2.7

參考：https://www.cnblogs.com/cdfive2018/p/11245036.html
dubbo官網：http://dubbo.apache.org/zh-cn/docs/user/versions/version-270.html

• 修改 dubbo 依賴，完成dubbo 升級

  <properties>
          <dubbo.version>2.7.4.1</dubbo.version>
  </properties>
  <dependencyManagement>
       <dependencies>
              <!--SpringBoot-->
              <dependency>
                  <groupId>org.springframework.boot</groupId>
                  <artifactId>spring-boot-dependencies</artifactId>
                  <version>2.1.9.RELEASE</version>
                  <type>pom</type>
                  <scope>import</scope>
              </dependency>
              <dependency>
                  <groupId>org.apache.dubbo</groupId>
                  <artifactId>dubbo-dependencies-bom</artifactId>
                  <version>${dubbo.version}</version>
                  <type>pom</type>
                  <scope>import</scope>
              </dependency>
              <!-- dubbo 依賴 -->
              <dependency>
                  <groupId>org.apache.dubbo</groupId>
                  <artifactId>dubbo-spring-boot-starter</artifactId>
                  <version>${dubbo.version}</version>
              </dependency>
              <!-- nacos 依賴 -->
              <dependency>
                  <groupId>org.apache.dubbo</groupId>
                  <artifactId>dubbo-registry-nacos</artifactId>
                  <version>${dubbo.version}</version>
              </dependency>
              <dependency>
                  <groupId>com.alibaba.boot</groupId>
                  <artifactId>nacos-config-spring-boot-starter</artifactId>
                  <version>0.2.3</version>
              </dependency>
       </dependencies>
  </dependencyManagement>
  

• 如果不修改任何代碼，也可以編譯通過，只是會提示：com.alibaba.dubbo.config.annotation.* 已棄用。

• 但是要想跑起來，還需要做如下修改：

  • 1.包名修改，將 com.alibaba.dubbo 改成 org.apache.dubbo， 會涉及到3個地方

    // 如果不修改Reference ，則無法 create bean
    import com.alibaba.dubbo.config.annotation.Reference;
    import org.apache.dubbo.config.annotation.Reference;
    
    import com.alibaba.dubbo.config.annotation.Service;
    import org.apache.dubbo.config.annotation.Service;
    
    import com.alibaba.dubbo.config.spring.context.annotation.EnableDubbo;
    import org.apache.dubbo.config.spring.context.annotation.EnableDubbo;
    

  • 2.解決循環引用的問題: ‘AServiceImpl’ has been injected into other beans [bServiceImpl] in its raw version as part of a **circular reference **

    • 在 AServiceImpl 前添加 @Lazy 註解 ，即可解決循環引用的問題

  • 3.解決 Failed to create adaptive(適應的) instance 的問題，此問題由raincat 引起

    // 錯誤內容如下：
    An attempt was made to call a method that does not exist
    ...
    The method's class, com.alibaba.dubbo.common.logger.LoggerAdapter, is available from the following locations:
        jar:file:/Users/howard/.m2/repository/org/apache/dubbo/dubbo/2.7.4.1/dubbo-2.7.4.1.jar!/com/alibaba/dubbo/common/logger/LoggerAdapter.class
        jar:file:/Users/howard/.m2/repository/com/alibaba/dubbo/2.5.3/dubbo-2.5.3.jar!/com/alibaba/dubbo/common/logger/LoggerAdapter.class
    
    It was loaded from the following location:
        file:/Users/howard/.m2/repository/org/apache/dubbo/dubbo/2.7.4.1/dubbo-2.7.4.1.jar
    
    Action:
    Correct the classpath of your application so that it contains a single, compatible version of com.alibaba.dubbo.common.logger.LoggerAdapter
    
    Exception in thread "DubboShutdownHook" java.lang.IllegalStateException: Failed to create adaptive instance: java.lang.IllegalStateException: Can't create adaptive extension interface org.apache.dubbo.common.extension.ExtensionFactory, cause: Extension instance ...
    

    // 從以上錯誤內容可以看出存在兩個版本的dubbo , 分別是2.5.3 和 2.7.4.1 ，其中 2.5.3 是由raincat 2.0.0 引入的。嘗試升級raincat 版本到 2.0.1，就解決了兩個dubbo版本的問題。注意：需要將raincat的註解的命名空間修改正確即可。
    import org.dromara.raincat.core.annotation.TxTransaction; 
    import org.dromara.raincat.annotation.TxTransaction;
    

• 4.解決 raincat init error 問題，raincat init exception:tx transaction ex:{}：Please check your configuration

  • 從github上的raincat 文檔，查到raincat 還不支持 dubbo 2.7版本，
  • 解決辦法只能是：棄用raincat，使用其他的分佈式事務代替raincat 。