spring实现远程方法调用

spring in action一书的读书笔记

使用spring实现远程方法调用可以极大简化开发

将一个spring bean包装成为RMI service

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1. <bean class="org.springframework.remoting.rmi.RmiServiceExporter"
2. p:service-ref="spitterService"
3. p:serviceName="SpitterService"
4. p:serviceInterface="com.habuma.spitter.service.SpitterService"
5. p:registryHost="rmi.spitter.com"
6. p:registryPort="1199"/>

调用发布的RMI service

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1. String serviceUrl = "rmi:/spitter/SpitterService";
2. SpitterService spitterService = (SpitterService)Naming.lookup(serviceUrl);

我们也可以使用spring进行配置

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1. <bean id="spitterService" class="org.springframework.remoting.rmi.RmiProxyFactoryBean" p:serviceUrl="rmi://localhost/SpitterService"
2. p:serviceInterface="com.habuma.spitter.service.SpitterService"/>

RMI有一个限制就是对防火墙不太友好，不容易穿过防火墙，这在局域网可以不用考虑，但是广域网就需要考虑这一点

Hessian,Burlap是Caucho科技提供的两种方法

Hessian基于二进制消息进行通信

Burlap基于xml格式消息进行通信

发布Hessian service

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1. <bean id="hessianSpitterService" class="org.springframework.remoting.caucho.HessianServiceExporter"
2. p:service-ref="spitterService"
3. p:serviceInterface="com.habuma.spitter.service.SpitterService"/>

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1. HessianServiceExporter在spring中是作为一个controller存在的，所以需要在web.xml(意味着必须是web项目)配置DispatcherServlet，将对Hessian service bean的请求映射到hessianSpitterService
2. <bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
3. <property name="mappings">
4. <value>
5. /spitter.service=hessianSpitterService
6. </value>
7. </property>
8. </bean>

调用发布的Hessian service

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1. <bean id="spitterService" class="org.springframework.remoting.caucho.HessianProxyFactoryBean"
2. p:serviceUrl="http://localhost:8080/Spitter/spitter.service"
3. p:serviceInterface="com.habuma.spitter.service.SpitterService"/>

发布Burlap service

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1. <bean id="burlapSpitterService" class="org.springframework.remoting.caucho.BurlapServiceExporter"
2. p:service-ref="spitterService"
3. p:serviceInterface="com.habuma.spitter.service.SpitterService"/>

调用 Burlap service

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1. <bean id="spitterService" class="org.springframework.remoting.caucho.BurlapProxyFactoryBean"
2. p:serviceUrl="http://localhost:8080/Spitter/spitter.service"
3. p:serviceInterface="com.habuma.spitter.service.SpitterService"/>

RMI使用jdk中的类库，但是对防火墙不太友好，burlap和hessian对防火墙友好但是使用了第三方的类库,Spring‘s HttpInvoker解决了这两个矛盾。使用spring‘s httpInvoker双发必须都是用spring

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1. <bean class="org.spring.framework.remoting.httpinvoker.HttpInvokerServiceExporter"
2. p:service-ref="spitterService"
3. p:serviceInterface="com.habuma.spitter.service.SpitterService"/>
4. HttpInvokerServiceExporter在spring中也是作为一个controller
5. 调用HttpInvoker service
6. <bean id="spitterService" class="org.springframework.remoting.httpinvoker.HttpInvokerProxyFactoryBean"
7. p:serviceUrl="http://localhost:8080/Spitter/spitter.service"
8. p:serviceInterface="com.habuma.spitter.service.SpitterService"/>

几种方式使用方法大体相同，只是使用的spring中的类不同