一个简单的dubbo+zookeeper的DEMO

最新推荐文章于 2025-09-12 18:08:49 发布

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最新推荐文章于 2025-09-12 18:08:49 发布

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文章标签： java 大数据操作系统

原文链接：http://www.cnblogs.com/liuyuchong/p/8426419.html

本文介绍如何使用Dubbo框架进行服务注册与调用，包括Zookeeper的安装配置、服务提供者的创建与启动、服务消费者的配置及调用流程。

1.zookeeper的安装（windows）

首先下载包：我用的是zookeeper-3.5.3-beta.tar

解压即可，然后把conf/zoo_sample.cfg重命名为zoo.cfg

打开修改配置文件：

dataDir=/tmp/zk1/data //保存数据的目录
dataLogDir=/tmp/zk1/log //保存日志文件的目录

启动：打开bin/zkServer.cmd即可

2.Demo组成

包结构如图：

common模块就一个接口HelloService

public interface HelloService {
    String hello(String str);
}

provider模块包括一个HelloService的实现类HelloServiceImpl

public class HelloServiceImpl implements HelloService {
    @Override
    public String hello(String str) {
        return "Hello"+str;
    }

    public static void main(String[] args) throws IOException {
        ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("dubbo-provider.xml");
        System.out.println("dubbo启动。。。");
        System.in.read();
    }
}

　　配置文件如下：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
    <!-- 应用名 -->
    <dubbo:application name="dubbodemo-provider"/>
    <!-- 连接到哪个本地注册中心 -->
    <dubbo:registry id="dubbodemo" address="zookeeper://localhost:2181"/>
    <!-- 用dubbo协议在20880端口暴露服务 -->
    <dubbo:protocol name="dubbo" port="28080"/>
    <!-- 声明需要暴露的服务接口 -->
    <dubbo:service registry="dubbodemo" interface="org.liu.HelloService" ref="HelloServiceImpl"/>
    <bean id="HelloServiceImpl" class="org.provider.HelloServiceImpl"/>
</beans>

　　pom包含的依赖

<dependencies>
        <dependency>
            <groupId>liu</groupId>
            <artifactId>common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>4.3.10.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.5.3</version>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring</artifactId>
                </exclusion>
                <exclusion>
                    <artifactId>netty</artifactId>
                    <groupId>org.jboss.netty</groupId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>3.4.10</version>
        </dependency>
        <dependency>
            <groupId>com.101tec</groupId>
            <artifactId>zkclient</artifactId>
            <version>0.10</version>
        </dependency>
    </dependencies>

　　接下来先开启服务提供者看看~ 运行HelloServiceImpl的main函数，发现有问题。。

Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.liu.HelloService': Instantiation of bean failed; nested exception is java.lang.ExceptionInInitializerError
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1155)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1099)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
	at org.provider.HelloServiceImpl.main(HelloServiceImpl.java:21)
Caused by: java.lang.ExceptionInInitializerError
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:142)
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:89)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1147)
	... 13 more
Caused by: java.lang.IllegalStateException: fail to create adaptive instance: java.lang.IllegalStateException: Can not create adaptive extenstion interface com.alibaba.dubbo.rpc.Protocol, cause: Failed to load extension class(interface: interface com.alibaba.dubbo.common.compiler.Compiler, class line: com.alibaba.dubbo.common.compiler.support.JavassistCompiler) in jar:file:/D:/apache-maven-3.5.0/localrepo/com/alibaba/dubbo/2.5.3/dubbo-2.5.3.jar!/META-INF/dubbo/internal/com.alibaba.dubbo.common.compiler.Compiler, cause: javassist/ClassPath
	at com.alibaba.dubbo.common.extension.ExtensionLoader.getAdaptiveExtension(ExtensionLoader.java:459)
	at com.alibaba.dubbo.config.ServiceConfig.<clinit>(ServiceConfig.java:60)
	... 20 more
Caused by: java.lang.IllegalStateException: Can not create adaptive extenstion interface com.alibaba.dubbo.rpc.Protocol, cause: Failed to load extension class(interface: interface com.alibaba.dubbo.common.compiler.Compiler, class line: com.alibaba.dubbo.common.compiler.support.JavassistCompiler) in jar:file:/D:/apache-maven-3.5.0/localrepo/com/alibaba/dubbo/2.5.3/dubbo-2.5.3.jar!/META-INF/dubbo/internal/com.alibaba.dubbo.common.compiler.Compiler, cause: javassist/ClassPath
	at com.alibaba.dubbo.common.extension.ExtensionLoader.createAdaptiveExtension(ExtensionLoader.java:723)
	at com.alibaba.dubbo.common.extension.ExtensionLoader.getAdaptiveExtension(ExtensionLoader.java:455)
	... 21 more
Caused by: java.lang.IllegalStateException: Failed to load extension class(interface: interface com.alibaba.dubbo.common.compiler.Compiler, class line: com.alibaba.dubbo.common.compiler.support.JavassistCompiler) in jar:file:/D:/apache-maven-3.5.0/localrepo/com/alibaba/dubbo/2.5.3/dubbo-2.5.3.jar!/META-INF/dubbo/internal/com.alibaba.dubbo.common.compiler.Compiler, cause: javassist/ClassPath
	at com.alibaba.dubbo.common.extension.ExtensionLoader.loadFile(ExtensionLoader.java:685)
	at com.alibaba.dubbo.common.extension.ExtensionLoader.loadExtensionClasses(ExtensionLoader.java:591)
	at com.alibaba.dubbo.common.extension.ExtensionLoader.getExtensionClasses(ExtensionLoader.java:567)
	at com.alibaba.dubbo.common.extension.ExtensionLoader.getAdaptiveExtensionClass(ExtensionLoader.java:728)
	at com.alibaba.dubbo.common.extension.ExtensionLoader.createAdaptiveExtension(ExtensionLoader.java:721)
	at com.alibaba.dubbo.common.extension.ExtensionLoader.getAdaptiveExtension(ExtensionLoader.java:455)
	at com.alibaba.dubbo.common.extension.ExtensionLoader.createAdaptiveExtensionClass(ExtensionLoader.java:738)
	at com.alibaba.dubbo.common.extension.ExtensionLoader.getAdaptiveExtensionClass(ExtensionLoader.java:732)
	at com.alibaba.dubbo.common.extension.ExtensionLoader.createAdaptiveExtension(ExtensionLoader.java:721)
	... 22 more
Caused by: java.lang.NoClassDefFoundError: javassist/ClassPath
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:348)
	at com.alibaba.dubbo.common.extension.ExtensionLoader.loadFile(ExtensionLoader.java:627)
	... 30 more
Caused by: java.lang.ClassNotFoundException: javassist.ClassPath
	at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:335)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 33 more

　　经过查询得知，是dubbo的版本和java8（我当前用的8~）不兼容，修改版本号为2.5.4解决~，如下

<groupId>com.alibaba</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.5.4</version>

　　发现dubbo可以正常运行了~

接下来启动消费服务，consumer模块就一个消费者类Consumer

public class Consumer {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("dubbo-consumer.xml");
        HelloService sayHello = (HelloService) ctx.getBean("helloService");
        for(int i=1;i<=3;i++){
            System.out.println(sayHello.hello("第" + i + "次调用消费者!"));
        }
    }
}

　配置文件dubbo-consumer.xml

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
    <!-- 应用名 -->
    <dubbo:application name="consumer-of-helloworld-app"/>
    <!-- 连接到哪个本地注册中心 -->
    <dubbo:registry address="zookeeper://localhost:2181"/>
    <!--引用的服务-->
    <dubbo:reference id="helloService" interface="org.liu.HelloService"/>
</beans>

　　运行Consumer的main函数结果如下：