【报错】Cannot invoke “...ZookeeperTransporter.connect“ because “zookeeperTransporter“ is null

Ethan__Z

已于 2025-01-14 10:38:49 修改

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文章标签： java 开发语言

于 2024-06-01 18:43:36 首次发布

本文链接：https://blog.youkuaiyun.com/Z_H_sheng/article/details/139377656

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问题

SpringBoot项目采用Dubbo + Zookeeper注册服务时，项目启动报错。

java.lang.NullPointerException: Cannot invoke "org.apache.dubbo.remoting.zookeeper.ZookeeperTransporter.connect(org.apache.dubbo.common.URL)" because "zookeeperTransporter" is null
	at org.apache.dubbo.configcenter.support.zookeeper.ZookeeperDynamicConfiguration.<init>(ZookeeperDynamicConfiguration.java:56) ~[dubbo-2.7.8.jar:2.7.8]
	at org.apache.dubbo.configcenter.support.zookeeper.ZookeeperDynamicConfigurationFactory.createDynamicConfiguration(ZookeeperDynamicConfigurationFactory.java:37) ~[dubbo-2.7.8.jar:2.7.8]
	at org.apache.dubbo.common.config.configcenter.AbstractDynamicConfigurationFactory.lambda$getDynamicConfiguration$0(AbstractDynamicConfigurationFactory.java:39) ~[dubbo-2.7.8.jar:2.7.8]
	at java.base/java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1708) ~[na:na]
	at org.apache.dubbo.common.config.configcenter.AbstractDynamicConfigurationFactory.getDynamicConfiguration(AbstractDynamicConfigurationFactory.java:39) ~[dubbo-2.7.8.jar:2.7.8]
	at org.apache.dubbo.common.config.configcenter.DynamicConfiguration.getDynamicConfiguration(DynamicConfiguration.java:224) ~[dubbo-2.7.8.jar:2.7.8]
	at org.apache.dubbo.config.bootstrap.DubboBootstrap.prepareEnvironment(DubboBootstrap.java:1034) ~[dubbo-2.7.8.jar:2.7.8]
	at org.apache.dubbo.config.bootstrap.DubboBootstrap.startConfigCenter(DubboBootstrap.java:623) ~[dubbo-2.7.8.jar:2.7.8]
	at org.apache.dubbo.config.bootstrap.DubboBootstrap.initialize(DubboBootstrap.java:521) ~[dubbo-2.7.8.jar:2.7.8]
	at org.apache.dubbo.config.bootstrap.DubboBootstrap.start(DubboBootstrap.java:896) ~[dubbo-2.7.8.jar:2.7.8]
	at org.apache.dubbo.config.spring.context.DubboBootstrapApplicationListener.onContextRefreshedEvent(DubboBootstrapApplicationListener.java:59) ~[dubbo-2.7.8.jar:2.7.8]
	at org.apache.dubbo.config.spring.context.DubboBootstrapApplicationListener.onApplicationContextEvent(DubboBootstrapApplicationListener.java:52) ~[dubbo-2.7.8.jar:2.7.8]
	at org.apache.dubbo.config.spring.context.OneTimeExecutionApplicationContextEventListener.onApplicationEvent(OneTimeExecutionApplicationContextEventListener.java:40) ~[dubbo-2.7.8.jar:2.7.8]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176) ~[spring-context-5.3.15.jar:5.3.15]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169) ~[spring-context-5.3.15.jar:5.3.15]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143) ~[spring-context-5.3.15.jar:5.3.15]
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:421) ~[spring-context-5.3.15.jar:5.3.15]
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:378) ~[spring-context-5.3.15.jar:5.3.15]
	at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:938) ~[spring-context-5.3.15.jar:5.3.15]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:586) ~[spring-context-5.3.15.jar:5.3.15]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:732) ~[spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:414) ~[spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) ~[spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1303) ~[spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1292) ~[spring-boot-2.6.3.jar:2.6.3]
	at com.horsa.dataservice.DataserviceApplication.main(DataserviceApplication.java:14) ~[classes/:na]

查找原因，报错信息解释为：“dubbo和zookeeper建立连接失败”，直观来说是dubbo中的ZookeeperTransporter对象初始化失败，为null导致空指针异常。

AI给出的解决方案：

1. 检查相关的 Dubbo 配置，确保 ZooKeeper 服务相关的配置是正确的，比如服务地址、端口等。
2. 确认 ZooKeeper 服务是否已经启动并且可用。
3. 检查代码中的对象是否在使用前已经正确初始化。确保任何可能返回 null 的方法调用都进行了空值检查。
4. 如果是使用 Dubbo 的注解或者 API 进行服务引用，确保服务提供者已经启动并且注册到了 ZooKeeper。
5. 如果是在使用 Dubbo 的过程中出现了这个异常，可以考虑查看 Dubbo 的日志输出，以获取更多关于为什么对象为 null 的信息。

解决步骤

首先，检查zookeeper是否正常运行，查看zkServer.cmd没问题
然后检查yml配置文件，重点检查dubbo.registry.address，改为localhost仍然报错

dubbo:
  registry:
    address: zookeeper://localhost:2181

再然后，检查依赖dubbo和zookeeper的依赖配置，版本是否一致等，没有问题

			<dependency>
                <groupId>org.apache.dubbo</groupId>
                <artifactId>dubbo-spring-boot-starter</artifactId>
                <version>${dubbo.version}</version>
            </dependency>
            <!--Zookeeper-->
            <dependency>
                <groupId>org.apache.dubbo</groupId>
                <artifactId>dubbo-dependencies-zookeeper</artifactId>
                <version>${zookeeper.version}</version>
                <type>pom</type>
                <exclusions>
                    <exclusion>
                        <groupId>org.slf4j</groupId>
                        <artifactId>slf4j-log4j12</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>