dubbo客户端初始化问题

ゝ一纸荒年。 2021-11-01 04:20 401阅读 0赞

背景：工作中遇到了调用dubbo服务的场景，项目不是spring项目，我只想简单的调用服务端的接口，不想加入那么多配置。

在服务对接中，遇到调用dubbo服务的场景。按照公司的框架给的开发文档，要加配置！要写注解！不符合我的期望。我只是想用一下Dubbo！

于是把目光转向了dubbo官网的示例。

1、添加依赖

首先是添加pom依赖，我是一步步添加这么多的

1 <spring.version>4.2.5.RELEASE</spring.version>
     2  
     3 <dependency>
     4    <groupId>com.alibaba</groupId>
     5    <artifactId>dubbo</artifactId>
     6    <version>2.6.2</version>
     7    <exclusions>
     8     <exclusion>
     9      <groupId>com.101tec</groupId>
    10      <artifactId>zkclient</artifactId>
    11     </exclusion>
    12    </exclusions>
    13   </dependency>
    14         <dependency>
    15             <groupId>org.springframework</groupId>
    16             <artifactId>spring-context</artifactId>
    17             <version>${spring.version}</version>
    18         </dependency>
    19         <dependency>
    20             <groupId>org.springframework</groupId>
    21             <artifactId>spring-beans</artifactId>
    22             <version>${spring.version}</version>
    23         </dependency>
    24   <dependency>
    25             <groupId>org.springframework</groupId>
    26             <artifactId>spring-core</artifactId>
    27             <version>${spring.version}</version>
    28         </dependency>
    29         <dependency>
    30      <groupId>org.springframework</groupId>
    31      <artifactId>spring-tx</artifactId>
    32      <version>${spring.version}</version>
    33   </dependency>

2、写代码

a、有错误的代码示例（Dubbo的示例，这也是坑的开始。）

1  ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"META-INF/spring/dubbo-demo-consumer.xml"});
     2         context.start();
     3         DemoService demoService = (DemoService) context.getBean("demoService"); // get remote service proxy
     4         while (true) {
     5             try {
     6                 Thread.sleep(1000);
     7                 String hello = demoService.sayHello("world"); // call remote method
     8                 System.out.println(hello); // get result
     9             } catch (Throwable throwable) {
    10                 throwable.printStackTrace();
    11             }
    12         }

我这样用了，项目启动的时候一直报错，如下：

2018-10-15 16:30:30 [org.springframework.beans.factory.xml.XmlBeanDefinitionReader]-[INFO] Loading XML bean definitions from class path resource [E:/opt/dwf/dwf-dispatch-center/conf/dubbo_consumer.xml]
    java.lang.reflect.InvocationTargetException
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
     at java.lang.reflect.Method.invoke(Method.java:498)
     at com.daojia.dwf.mvc.initial.app.AppInitial.initial(AppInitial.java:30)
     at com.daojia.dwf.mvc.DWFBootstrap.init(DWFBootstrap.java:71)
     at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:279)
     at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:260)
     at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:105)
     at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4950)
     at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5652)
     at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
     at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1694)
     at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1684)
     at java.util.concurrent.FutureTask.run(FutureTask.java:266)
     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
     at java.lang.Thread.run(Thread.java:748)
    Caused by: java.lang.ExceptionInInitializerError
     at com.daojia.dispatchcenter.inits.ServerInit.initial(ServerInit.java:38)
     ... 18 more
    Caused by: org.springframework.beans.factory.BeanDefinitionStoreException: IOException parsing XML document from class path resource [E:/opt/dwf/dwf-dispatch-center/conf/dubbo_consumer.xml]; nested exception is java.io.FileNotFoundException: class path resource [E:/opt/dwf/dwf-dispatch-center/conf/dubbo_consumer.xml] cannot be opened because it does not exist
     at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:344)
     at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:304)
     at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:181)
     at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:217)
     at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:188)
     at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:252)
     at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:127)
     at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:93)
     at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:129)
     at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:614)
     at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:515)
     at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
     at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:93)
     at com.daojia.dispatchcenter.inits.DubboInit.<clinit>(DubboInit.java:33)
     ... 19 more
    Caused by: java.io.FileNotFoundException: class path resource [E:/opt/dwf/dwf-dispatch-center/conf/dubbo_consumer.xml] cannot be opened because it does not exist
     at org.springframework.core.io.ClassPathResource.getInputStream(ClassPathResource.java:172)
     at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:330)
     ... 32 more

一直报找不到配置，这就奇怪了。尝试了许多次，依然这样。

我在代码里尝试把配置文件打印出来，内容是可以打印出来的。这说明路径是没有错的。

搜索了一番，

[https://blog.csdn.net/tiananma0607/article/details/76595187][https_blog.csdn.net_tiananma0607_article_details_76595187]

看了这篇文章之后，才了解到，

ClassPathXmlApplicationContext 对于文件的路径是有要求的。类似于类需要先被加载一样。我这配置文件很明显是没有被提前加载的。

因为使用框架的原因，我又不想把配置放到那个目录下，于是查看该继承的父类，找到了“FileSystemXmlApplicationContext”这个方法，改了之后，不再提示那个错误了。

b、正常的代码

1 String configFolder = Config.getConfigFolder();
    2 if(configFolder.startsWith("/")) {
    3     configFolder = "/" + configFolder;
    4 }
    5 String dubboConfig = configFolder + ServerInit.getConfigPath(SystemConstant.DUBBO_CONFIG_NAME);
    6 log.warn("DubboInit,dubboConfig:" + dubboConfig);
    7 FileSystemXmlApplicationContext context = new FileSystemXmlApplicationContext(new String[] {dubboConfig});
    8 context.start();

转载于:https://www.cnblogs.com/shuimutong/p/11047255.html

[https_blog.csdn.net_tiananma0607_article_details_76595187]: https://blog.csdn.net/tiananma0607/article/details/76595187