Spring让Hessian变得不但强大，而且易用，但是易用背后，却有不少陷阱！
这个例子很简单，但实际上的确花费了我超过一小时的时间，排除了种种问题，最后问题终于水落石出。
整合以上篇Hello Hessian为基础，加入Spring框架，进行改进。
一、环境
jdk1.5
http://labs.xiaonei.com/apache-mirror/tomcat/tomcat-6/v6.0.20/bin/apache-tomcat-6.0.20.zip
http://s3.amazonaws.com/dist.springframework.org/release/SPR/spring-framework-2.5.6.SEC01-with-dependencies.zip
http://s3.amazonaws.com/dist.springframework.org/release/SPR/spring-framework-2.5.6.SEC01-with-dependencies.zip
顺便说下，如果不说环境版本，很难保证你的程序在别的版本下能运行。
二、整合
1、写Spring的发布Hessian服务的配置文件
hessian-servlet.xml
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
< beans >
< bean id ="defaultHandlerMapping" class ="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping" />
< bean id ="helloService" class ="lavasoft.suths.service.HelloService" />
< bean name ="/hello" class ="org.springframework.remoting.caucho.HessianServiceExporter" >
< property name ="service" ref ="helloService" />
< property name ="serviceInterface" value ="lavasoft.suths.service.Hello" />
</ bean >
</ beans >
< beans >
< bean id ="defaultHandlerMapping" class ="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping" />
< bean id ="helloService" class ="lavasoft.suths.service.HelloService" />
< bean name ="/hello" class ="org.springframework.remoting.caucho.HessianServiceExporter" >
< property name ="service" ref ="helloService" />
< property name ="serviceInterface" value ="lavasoft.suths.service.Hello" />
</ bean >
</ beans >
2、配置web.xml
<?
xml
version
="1.0"
encoding
="UTF-8"
?>
< web-app 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"
version ="2.5" >
< context-param >
< param-name >contextConfigLocation </ param-name >
< param-value >
/WEB-INF/hessian-servlet.xml
</ param-value >
</ context-param >
< servlet >
< servlet-name >hessian </ servlet-name >
< servlet-class >org.springframework.web.servlet.DispatcherServlet </ servlet-class >
< load-on-startup >4 </ load-on-startup >
</ servlet >
< servlet-mapping >
< servlet-name >hessian </ servlet-name >
< url-pattern >/hessian/* </ url-pattern >
</ servlet-mapping >
</ web-app >
< web-app 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"
version ="2.5" >
< context-param >
< param-name >contextConfigLocation </ param-name >
< param-value >
/WEB-INF/hessian-servlet.xml
</ param-value >
</ context-param >
< servlet >
< servlet-name >hessian </ servlet-name >
< servlet-class >org.springframework.web.servlet.DispatcherServlet </ servlet-class >
< load-on-startup >4 </ load-on-startup >
</ servlet >
< servlet-mapping >
< servlet-name >hessian </ servlet-name >
< url-pattern >/hessian/* </ url-pattern >
</ servlet-mapping >
</ web-app >
陷阱：
a）hessian-servlet.xml的文件名必须以<servlet-name>hessian</servlet-name>名字开头，并且加上-servlet.xml一段，组成完整的文件名。
b）hessian-servlet.xml的文件名格式必须是[servlet-name]-servlet.xml格式，否则出错。
三、部署应用
因为涉及到类加载顺序问题，好用IDEA启动Tomcat测试老失败，不知道为啥！这次不用IDEA嵌入式启动Tomcat了，直接自己部署测试。
部署后，启动界面如下：
三、写测试
这次测试，可以在上个例子的基础上进行修改来测试，根据上面的配置，那么请求HelloService的URL应该是：
http://localhost:8080/hessianapp/hessian/hello
package lavasoft.suths.service.client;
import com.caucho.hessian.client.HessianProxyFactory;
import lavasoft.suths.service.Hello;
import java.net.MalformedURLException;
/**
* 客户端调用（会依赖服务接口）
*
* @author leizhimin 2009-8-14 12:29:33
*/
public class Client {
public static void main(String[] args) throws MalformedURLException {
String url = "http://localhost:8080/hessianapp/hessian/hello";
HessianProxyFactory factory = new HessianProxyFactory();
Hello hello = (Hello) factory.create(Hello.class, url);
System.out.println(hello.sayHello("Hessian"));
}
}
import com.caucho.hessian.client.HessianProxyFactory;
import lavasoft.suths.service.Hello;
import java.net.MalformedURLException;
/**
* 客户端调用（会依赖服务接口）
*
* @author leizhimin 2009-8-14 12:29:33
*/
public class Client {
public static void main(String[] args) throws MalformedURLException {
String url = "http://localhost:8080/hessianapp/hessian/hello";
HessianProxyFactory factory = new HessianProxyFactory();
Hello hello = (Hello) factory.create(Hello.class, url);
System.out.println(hello.sayHello("Hessian"));
}
}
运行结果：
Hello Hessian!
Process finished with exit code 0
Process finished with exit code 0
还有一种测试方法，就是在客户端也使用Spring，需要做个配置remoting-client.xml：
<!DOCTYPE beans PUBLIC
"-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<bean id="helloServiceClient" class="org.springframework.remoting.caucho.HessianProxyFactoryBean">
<property name="serviceUrl" value="http://localhost:8080/hessianapp/hessian/hello"/>
<property name="serviceInterface" value="lavasoft.suths.service.Hello"/>
</bean>
</beans>
<beans>
<bean id="helloServiceClient" class="org.springframework.remoting.caucho.HessianProxyFactoryBean">
<property name="serviceUrl" value="http://localhost:8080/hessianapp/hessian/hello"/>
<property name="serviceInterface" value="lavasoft.suths.service.Hello"/>
</bean>
</beans>
然后写个测试类：
package lavasoft.suths.service.client;
import lavasoft.suths.service.Hello;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
* Spring整合Hessian，客户端测试
*
* @author leizhimin 2009-8-14 15:32:46
*/
public class TestClient {
public static void main(String[] args) {
try {
ApplicationContext context = new ClassPathXmlApplicationContext( "/remoting-client.xml");
Hello hello = (Hello) context.getBean( "helloServiceClient");
System.out.println(hello.sayHello( "Spring Hession"));
}
catch (Exception e) {
e.printStackTrace();
}
}
}
import lavasoft.suths.service.Hello;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
* Spring整合Hessian，客户端测试
*
* @author leizhimin 2009-8-14 15:32:46
*/
public class TestClient {
public static void main(String[] args) {
try {
ApplicationContext context = new ClassPathXmlApplicationContext( "/remoting-client.xml");
Hello hello = (Hello) context.getBean( "helloServiceClient");
System.out.println(hello.sayHello( "Spring Hession"));
}
catch (Exception e) {
e.printStackTrace();
}
}
}
运行结果：
Hello Spring Hession!
Process finished with exit code 0
Process finished with exit code 0
陷阱：
实际上，看着代码好好，程序有时候还是不能跑，原因是Hessian的版本问题，这里推荐使用Spring自带的版本，就不会有问题了。
整个工程所以依赖的包：
log4j-1.2.15.jar
spring-aop.jar
spring-beans.jar
spring-context.jar
spring-context-support.jar
spring-core.jar
spring-jdbc.jar
spring-jms.jar
spring-orm.jar
spring-test.jar
spring-tx.jar
spring-web.jar
spring-webmvc.jar
spring-webmvc-portlet.jar
spring-webmvc-struts.jar
hessian-3.1.3.jar
aopalliance.jar
commons-logging.jar
spring-aop.jar
spring-beans.jar
spring-context.jar
spring-context-support.jar
spring-core.jar
spring-jdbc.jar
spring-jms.jar
spring-orm.jar
spring-test.jar
spring-tx.jar
spring-web.jar
spring-webmvc.jar
spring-webmvc-portlet.jar
spring-webmvc-struts.jar
hessian-3.1.3.jar
aopalliance.jar
commons-logging.jar
本文转自 leizhimin 51CTO博客，原文链接：http://blog.51cto.com/lavasoft/191871，如需转载请自行联系原作者
