一个简单的dubbo+zookeeper的DEMO
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：
