Http Invoker使用HTTP传送物件,传送时使用Java的序列化机制来传送,由于透过HTTP传送,所以 在使用它们时要搭配Spring Web框架来使用,也就是使用到DispatcherServlet,可以改写 Hessian、 Burlap,只要修改一下service‐config.xml就可以了:
• service‐config.xml
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE beans PUBLIC "-//SPRING/DTD BEAN/EN""http://www.springframework.org/dtd/spring-beans.dtd"> <beans> <bean id="urlMapping" class="org.springframework.web.servlet. → handler.SimpleUrlHandlerMapping"> <property name="mappings"> <props> <prop key="/some.service">serviceExporter</prop> </props> </property> </bean> <bean id="viewResolver" class="org.springframework.web.servlet. → view.InternalResourceViewResolver"> <property name="prefix"> <value>/WEB-INF/jsp/</value> </property> <property name="suffix"> <value>.jsp</value> </property> </bean> <bean id="someService" class="onlyfun.caterpillar.SomeServiceImpl"/> <bean id="serviceExporter" class="org.springframework.remoting. → httpinvoker.HttpInvokerServiceExporter"> <property name="service"> <ref bean="someService"/> </property> <property name="serviceInterface"> <value>onlyfun.caterpillar.ISomeService</value> </property> </bean> </beans>bsp;
接下来客户端的部份,可以改写 Hessian、Burlap 的内容,修改一下Bean定义档的内容:
• invoker‐client.xml
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE beans PUBLIC "-//SPRING/DTD BEAN/EN""http://www.springframework.org/dtd/spring-beans.dtd"> <beans> <bean id="someServiceProxy" class="org.springframework.remoting. → httpinvoker.HttpInvokerProxyFactoryBean"> <property name="serviceUrl"> <value> http://localhost:8080/HttpInvokerDemo/some.service </value> </property> <property name="serviceInterface"> <value>onlyfun.caterpillar.ISomeService</value> </property> </bean> </beans>
注意到"serviceUrl"属性的设定,它是个标准的 HTTP 请求位址,来撰写个简单的客户端程式以使 用 Http Invoker 伺服器上的服务:
• HessianClient.java
package onlyfun.caterpillar; import org.springframework.context.ApplicationContext; import org.springframework.context. support.FileSystemXmlApplicationContext; public class HessianClient { public static void main(String[] args) { ApplicationContext context =new FileSystemXmlApplicationContext( "invoker-client.xml"); ISomeService service =(ISomeService) context.getBean("someServiceProxy"); String result1 = service.doSomeService("Some request"); System.out.println(result1); int result2 = service.doOtherService(1); System.out.println(result2); } }
执行的结果与 RMI 是相同的。