前言
前面我已经介绍了dubbo的一些基本工具和知识,让大家简单的了解了下RPC框架和Dubbo。接下来就是重点了,Dubbo的helloworld项目。
一、搭建项目
首先我们新建三个maven项目如下图:
- dubbo-provider(服务提供者)
- dubbo-api(api提供者)
- dubbo-consumer(消费者)
OKOK!这里我们再简单介绍下API项目。我前面说了,只有消费者和生产者是没错的。but你想啊,你在生产者项目中要用接口,消费者中要用接口,是是不是两个项目都TM要写同样的代码啊,那多麻烦!!
所以这里我们用一个项目把需要的公共代码丢进去,一些接口啊,实体啊啥的,然后打成jar包导入到生产者和消费者中,多完美。
API项目:
由于helloworld的demo过于简单,这里我们就丢一个公共接口放里面。
package com.provider;
/**
* ClassName:DemoService
* Function: TODO ADD FUNCTION.
* Date: 2017年11月28日 下午6:43:49
* @author HXY
*/
public interface DemoService {
String sayHello(String name);
}
然后pom文件只需要注明版本号信息啥的:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>hxy.superFather.forJava</groupId>
<artifactId>dubbo-api</artifactId>
<packaging>jar</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>dubbo-api Maven Webapp</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<finalName>dubbo-api</finalName>
</build>
</project>
provider项目:
接口实现类:
package com.provider.impl;
import com.bean.User;
import com.provider.DemoService;
/**
* ClassName:DemoServiceImpl
* Function: TODO ADD FUNCTION.
* Date: 2017年11月29日 上午9:31:23
* @author HXY
*/
public class DemoServiceImpl implements DemoService {
@Override
public String sayHello(String name) {
return "Hello " + name;
}
}
服务注册启动类:
package com;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Provider {
public static void main(String[] args) throws Exception {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(
new String[] { "provider.xml" });
context.start();
System.in.read(); // 为保证服务一直开着,利用输入流的阻塞来模拟
}
}
spring整合dubbo配置文件provider.xml:
<?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">
<!-- 提供方应用信息,用于计算依赖关系 -->
<dubbo:application name="dubbo-provider-app" />
<!-- 使用zookeeper注册中心暴露服务地址 -->
<!-- 使用multicast广播注册中心暴露服务地址 -->
<!-- <dubbo:registry address="multicast://224.5.6.7:1234" /> -->
<!-- 用dubbo协议在20880端口暴露服务 -->
<dubbo:protocol name="dubbo" port="20880" />
<!-- 使用zookeeper注册中心暴露服务地址 -->
<dubbo:registry address="zookeeper://127.0.0.1:2181?backup=127.0.0.1:2182,127.0.0.1:2183" />
<!-- 声明需要暴露的服务接口 -->
<dubbo:service interface="com.provider.DemoService" ref="demoService" />
<!-- 和本地bean一样实现服务 -->
<bean id="demoService" class="com.provider.impl.DemoServiceImpl" />
</beans>
pom配置文件:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>dubbo</groupId>
<artifactId>dubbo-provider</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>dubbo-provider Maven Webapp</name>
<url>http://maven.apache.org</url>
<properties>
<!-- spring版本号 -->
<spring.version>4.0.2.RELEASE</spring.version>
<!-- mybatis版本号 -->
<mybatis.version>3.2.6</mybatis.version>
<!-- log4j日志文件管理包版本 -->
<slf4j.version>1.7.7</slf4j.version>
<log4j.version>1.2.17</log4j.version>
<!-- shiro版本号 -->
<shiro.version>1.2.3</shiro.version>
</properties>
<dependencies>
<!-- 6 dubbo zookeeper相关依赖start -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo</artifactId>
<version>2.5.3</version>
<exclusions>
<exclusion>
<groupId>org.springframework</groupId>
<artifactId>spring</artifactId>
</exclusion>
<exclusion>
<groupId>org.jboss.netty</groupId>
<artifactId>netty</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.4.6</version>
</dependency>
<dependency>
<groupId>com.github.sgroschupf</groupId>
<artifactId>zkclient</artifactId>
<version>0.1</version>
</dependency>
<dependency>
<groupId>hxy.superFather.forJava</groupId>
<artifactId>dubbo-api</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
<!-- junit配置 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<!-- 导入java ee jar 包 -->
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>7.0</version>
</dependency>
<!-- spring核心包 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-oxm</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- json数据 -->
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-core-asl</artifactId>
<version>1.9.13</version>
</dependency>
<dependency>
<groupId>net.sf.json-lib</groupId>
<artifactId>json-lib</artifactId>
<version>2.4</version>
<classifier>jdk15</classifier>
</dependency>
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-asl</artifactId>
<version>1.9.13</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>2.8.5</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.7.7</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.8.9</version>
</dependency>
<!-- JSTL标签类 -->
<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
</dependencies>
<build>
<finalName>dubbo-provider</finalName>
</build>
</project>
DubboConsummer项目:
消费类:
public static void main(String[] args) throws Exception {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(
new String[] { "spring-common.xml" });
context.start();
for(int i = 0;i<10;i++){
DemoService demoService = (DemoService) context.getBean("demoService");
String hello = demoService.sayHello("tom");
System.out.println("-------------"+hello);
Thread.sleep(5000);
}
System.in.read();
System.out.println("end");
}
spring整合dubbo配置文件:
<?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:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context"
xmlns:task="http://www.springframework.org/schema/task"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/task
http://www.springframework.org/schema/task/spring-task-3.0.xsd">
<import resource="classpath:spring-dubbo.xml"/>
</beans>
<?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
">
<!-- 提供方应用信息,用于计算依赖关系 -->
<dubbo:application name="counmser" />
<!-- 使用multicast广播注册中心暴露服务地址 -->
<!--<dubbo:registry address="multicast://224.5.6.7:1234" /> -->
<!-- 使用zookeeper注册中心暴露服务地址 即zookeeper的所在服务器ip地址和端口号 -->
<dubbo:registry address="zookeeper://127.0.0.1:2181?backup=127.0.0.1:2182,127.0.0.1:2183" />
<!-- 生成远程服务代理,可以像使用本地bean一样使用demoService -->
<dubbo:reference id="demoService"
interface="com.provider.DemoService" />
</beans>
二、运行
在正常项目部署中,我们会打包成可执行的jar文件启动,就还需要配置pom才能让maven打包。
但是这个我们后续再讲,今天的demo我们就用eclipse的main方法执行了,原理其实一样的。
- 首先打开zookeeper工具
- 启动服务提供者,他会自动注册到配置文件配置的zookeeper中
- 启动消费者,调用服务
然后看到这样的打印,说明成功了,dubbo的基本使用原理在做helloworld项目过程中,也应该有了大致了解。
三、其他问题解决
- spring-dubbo整合的配置文件中,dubbo配置项红叉报错问题。
原因:
因为dubbo.xsd文件找不到吧,好像是这个原因!
解决方案:
- 到maven库中找到dubbo的jar包,将其解压。
- 找到解压文件夹下的META-INF文件夹下的dubbo.xsd。
- eclipse选择windows->preferrence->xml->xml Catalog,右侧add-xml文件,在文件目录中选择dubbo.xsd。
- 下面的key值填写配置文件中一致的 http://code.alibabatech.com/schema/dubbo/dubbo.xsd
如下图:
确定完成之后重新验证配置文件即可。