阿里巴巴dubbo处理文件上传下载

 

 注：使用InputStream 作为方法参数的时候，需要将该参数作为方法的最后一个参数，否则会有问题

 

 

dubbo和hessian的maven依赖：

 

		<dependency>
			<groupId>com.alibaba</groupId>
			<artifactId>dubbo</artifactId>
			<version>2.5.3</version>
		</dependency>
		<dependency>
			<groupId>com.caucho</groupId>
			<artifactId>hessian</artifactId>
			<version>4.0.7</version>
		</dependency>

 

 

 

服务提供者（项目名称：provider）

 

首先是web.xml配置（使用spring）：

 

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>classpath*:applicationContext.xml</param-value>
	</context-param>
	<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>
	<servlet>
		<servlet-name>dubbo</servlet-name>
		<servlet-class>com.alibaba.dubbo.remoting.http.servlet.DispatcherServlet</servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>dubbo</servlet-name>
		<url-pattern>/*</url-pattern>
	</servlet-mapping>

</web-app>

 

 

 

然后是服务接口：

 

package com.tch.test.dubbo.service;


public interface DemoService {

        String sayHello(String name);
	/**
	 *  Created on: 			2013-12-11 
	 * <p>Discription:			下载</p>
	 * @return 				InputStream
	 */
	public InputStream download(String path);
        /**
         * 处理上传
         * @param in
         * @return
         */
        String upload(String destPath,InputStream in);
}

 

 

 

服务实现类：

 

package com.tch.test.dubbo.service;


import java.io.FileInputStream;
import java.io.InputStream;

public class DemoServiceImpl implements DemoService {
	@Override
	public InputStream download(String path) {
		System.out.println(path+"******************************");
		try {
			InputStream inputStream = new FileInputStream(path);
			return inputStream;
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}
	@Override
	public String sayHello(String name) {
        return "Hello " + name;
    }
	@Override
	public String upload(String destPath,InputStream in) {
		try {
			//FileOutputStream out = new FileOutputStream("E:\\temp\\a.js");
			int n = -1;
			byte[] b = new byte[10240];
			while((n=in.read(b)) != -1){
				System.out.println(new String(b,0,n,"utf-8"));
				//out.write(b, 0, n);
			}
			//out.close();
			//out.flush();
			in.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
		return "upload complete !";
	}

}

 

 

 

 

最重要的applicationContext.xml ：

 

参考：dubbo hessian协议

 

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:dubbo="http://code.alibabatech.com/schema/dubbo" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
				http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
        			http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd
				http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">
	<!-- 提供方应用信息，用于计算依赖关系 -->
    <dubbo:application name="hello-world-app"  />
    <!-- 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hessian协议在8080(servlet容器的端口)端口暴露服务，contextpath是项目名称，server这里是使用的web.xml里面配置的servlet -->
    <dubbo:protocol name="hessian" port="8080" contextpath="dubbo" server="servlet"/>
    <!-- 声明需要暴露的服务接口 -->
    <dubbo:service interface="com.tch.test.dubbo.service.DemoService" ref="demoService" />
    <!-- 和本地bean一样实现服务 -->
    <bean id="demoService" class="com.tch.test.dubbo.service.DemoServiceImpl" />
	
</beans>

 

启动项目之后，就同时启动了服务。。。

 

 

 

 

下面是 consumer ：

 

首先是服务接口：

 

package com.tch.test.dubbo.service;


public interface DemoService {

        String sayHello(String name);
	/**
	 *  Created on: 			2013-12-11 
	 * <p>Discription:			下载</p>
	 * @return 				InputStream
	 */
	public InputStream download(String path);
        /**
         * 处理上传
         * @param in
         * @return
         */
        String upload(String destPath,InputStream in);
}

 

 

 

 

然后是applicationContext.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
        ">
	<!-- 消费方应用名，用于计算依赖关系，不是匹配条件，不要与提供方一样 -->
	<dubbo:application name="consumer-of-helloworld-app" />

	<!-- 使用multicast广播注册中心暴露发现服务地址 -->
	<dubbo:registry address="multicast://224.5.6.7:1234" />

	<!-- 生成远程服务代理，可以和本地bean一样使用demoService -->
	<dubbo:reference id="demoService"
		interface="com.tch.test.dubbo.service.DemoService" />

</beans>

 

 

好了，开始调用provider提供的服务：

 

package com.alibaba.dubbo;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.alibaba.dubbo.demo.DemoService;
public class Consumer {
    public static void main(String[] args) throws Exception {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[] {"applicationContext.xml"});
        context.start();
        DemoService demoService = (DemoService)context.getBean("demoService"); // 获取远程服务代理
        sayHello(demoService);  //sayHello
        upload(demoService);    //upload
        download(demoService); //download
        context.close();
    }
    //调用sayHello
    public static void sayHello(DemoService demoService){
    	String result = demoService.sayHello(" dubbo "); // 执行远程方法
        System.out.println(result); // 显示调用结果
    }
    //调用upload
    public static void upload(DemoService demoService) throws FileNotFoundException{
    	String result = demoService.upload("E:\\temp\\a.js",new FileInputStream("D:\\Program files\\apache-maven-3.1.0\\repository\\com\\caucho\\hessian\\4.0.7\\hessian-4.0.7.pom")); // 执行远程方法
        System.out.println(result); // 显示调用结果
    }
    
    //调用upload
    public static void download(DemoService demoService) throws Exception{
    	String srcPath = "D:\\Program files\\apache-maven-3.1.0\\repository\\com\\caucho\\hessian\\4.0.7\\hessian-4.0.7.pom";
    	InputStream inputStream = demoService.download(srcPath); // 执行远程方法
    	byte b[] = new byte[1024];
		int n;
		try {
			while ((n = inputStream.read(b)) != -1) {
				System.out.print(new String(b,0,n,"utf-8"));
			}
		} catch (Exception e) {
			e.printStackTrace();
		}finally{
			inputStream.close();
		}
    }
}

 

 

 如果调用到download方法的时候，出现 java.io.IOException: stream is closed    

 

 则此时应该是jar包的问题，貌似这是hessian的一个bug ： 关于该bug

 

解决方法下载hessian.jar的源码包，修改 com.caucho.hessian.client.HessianProxy ：

 

在   Object value = in.readReply(method.getReturnType()); 这一句话之后加上下面代码：

 

	 if (value instanceof InputStream) {
         value = new ResultInputStream(conn, is, in, (InputStream) value);
         is = null;
         conn = null;
	 }

 

然后重新打包，使用这个新的jar包就没问题了。。。

 

然后，就可以看到sayHello、下载、上传成功的结果了。。。

 

 最后提供一个我自己修改过之后的hessian.jar

 

 

 

 

评论

3 楼 g_tao 2016-03-24  

作者你好，你这个例子中服务端是跑在tomcat中吗

2 楼 g_tao 2016-03-24  

作者你好，能把整个项目给我发一份吗？[e-mail]

1 楼 huyuran 2015-05-05