Hessian是远程调用的一种技术，和WebService类似，但不同的是较WebService而言，它更轻量级，更简单，更快速。
关于Hessian更详细全面的介绍可以查看http://hessian.caucho.com/。
下面就用一个例子来简单的使用Hessian。
一、创建服务端：
1、在Eclipse建立一个Maven webapp项目hessian，如图：
2、在项目中添加Hessian的依赖pom.xml:
<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>hessian</groupId>
<artifactId>com.xt.hessian</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>com.xt.hessian Maven Webapp</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.8.2</version>
</dependency>
<dependency>
<groupId>com.caucho</groupId>
<artifactId>hessian</artifactId>
<version>4.0.7</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
</dependency>
</dependencies>
<build>
<finalName>com.xt.hessian</finalName>
</build>
</project>
3、添加一个提供Hessian服务的接口和实现类：
package com.xt.hessian;
/**
* @ClassName: HessianService
* @Description: Hessian服务接口
* @date 2015-04-29 下午10:41:26
*
*/
public interface HessianService {
public String sayHello(String name);
}
package com.xt.hessian.impl;
import com.caucho.hessian.server.HessianServlet;
import com.xt.hessian.HessianService;
public class HessianServiceImpl extends HessianServlet implements HessianService {
/**
* @Description: Hessian服务接口实现类
*/
private static final long serialVersionUID = 1L;
@Override
public String sayHello(String name) {
return "hello " + name;
}
}
4、web.xml配置：
<?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">
<display-name>Archetypes Created Web Application</display-name>
<servlet>
<servlet-name>service</servlet-name>
<servlet-class>com.xt.hessian.impl.HessianServiceImpl</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>service</servlet-name>
<url-pattern>/service</url-pattern>
</servlet-mapping>
</web-app>
二、创建客户端：创建测试类：
package hessian;
import java.net.MalformedURLException;
import org.junit.Test;
import com.caucho.hessian.client.HessianProxyFactory;
import com.xt.hessian.HessianService;
public class HessianServiceTest {
private final static String SERVICE_URL = "http://localhost:8088/hessian/service";
@Test
public void testSayHello() {
HessianProxyFactory proxyFactory = new HessianProxyFactory();
try {
HessianService hessianService = (HessianService) proxyFactory.create(HessianService.class, SERVICE_URL);
System.out.println(hessianService.sayHello("hessian!!!"));
} catch (MalformedURLException e) {
e.printStackTrace();
}
}
}
运行结果：
hello hessian!!!
三、注意：如果服务端不启动，会报如下错误：
