在进行基于Hessian的项目开发时,应当注意以下几点:
▲JAVA服务器端必须具备以下几点:
·包含Hessian的jar包。
·设计一个接口,用来给客户端调用。
·实现该接口的功能。
·配置web.xml,配好相应的servlet。
·对象必须实现Serializable 接口。
·对于复杂对像可以使用Map的方法传递。
▲客户端必须具备以下几点:
·java客户端包含Hessian.jar的包。
·具有和服务器端结构一样的接口。
·利用HessianProxyFactory调用远程接口。
下面是一个hessian的简单例子
场景1:服务端 客户端都不使用spring
Java服务器端:
环境:j2sdk1.4.2、Tomcat6.0
依赖的包:hessian-3.1.6.jar
新建一个名为HessianServer的web project。将hessian-3.2.0.jar放入WEB-INF/lib文件夹中。
创建接口
package com.mooing.hessian; public interface DemoApi { public void setName(String name); public String sayHello(); public User getUser(); }
实现接口
package com.mooing.hessian; public class DemoService implements DemoApi{ private String name; @Override public void setName(String name) { this.name=name; } @Override public String sayHello() { System.out.println("hello,world!"); return "hello:"+name; } @Override public User getUser() { return new User("ming","m123"); } }
创建User,注意实现序列化
package com.mooing.hessian; import java.io.Serializable; public class User implements Serializable { private static final long serialVersionUID = 1L; private String name = "kitty"; private String psw = "nopww"; public User() { } public User(String name, String psw) { super(); this.name = name; this.psw = psw; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getPsw() { return psw; } public void setPsw(String psw) { this.psw = psw; } }
配置web.xml
<servlet> <servlet-name>hessian</servlet-name> <servlet-class>com.caucho.hessian.server.HessianServlet</servlet-class> <init-param> <param-name>service-class</param-name> <param-value>com.mooing.hessian.DemoService</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>hessian</servlet-name> <url-pattern>/helloworld</url-pattern> </servlet-mapping>
客户端代码
注意如果新建客户端工程,需引入上述jar,还需要服务端导出DemoService和User两个类的jar,放入lib。或创建两个一摸一样的类。
package com.mooing.hessian; import java.net.MalformedURLException; import com.caucho.hessian.client.HessianProxyFactory; public class HessianClient { public static void main(String[] args) throws MalformedURLException, ClassNotFoundException { String url = "http://localhost:8080/jms1/helloworld"; HessianProxyFactory pf = new HessianProxyFactory(); DemoApi da = (DemoApi) pf.create(url); da.setName("test"); System.out.println(da.sayHello()); System.out.println(da.getUser()); } }
tomcat启动服务端,运行客户端,结果如下
hello:test
ming
m123
场景2:服务端 客户端都使用spring(在上述基础上)
依赖的包:
1. Hessian包:hessian-3.1.6.jar
2. spring-framework-2.0.2包:
a) aopalliance.jar
b) commons-logging.jar
c) log4j-1.2.14.jar
d) spring.jar
e) spring-aop.jar
f) spring-beans.jar
g) spring-context.jar
h) spring-core.jar
i) spring-jdbc.jar
j) spring-jms.jar
k) spring-web.jar
l) spring-webmvc.jar
配置web.xml,web.xml中增加:
<servlet> <servlet-name>remote</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>namespace</param-name> <param-value>classes/remote-servlet</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>remote</servlet-name> <url-pattern>/remote/*</url-pattern> </servlet-mapping> 以下是remote-servlet.xml的内容: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"> <!-- 注入内部实现接口 --> <bean id="demoService" class="com.mooing.hessian.DemoService" /> <!-- 注入hessian发布接口 name为调用名称--> <bean name="/helloDemo" class="org.springframework.remoting.caucho.HessianServiceExporter"> <!-- 关联接口实现 --> <property name="service" ref="demoService" /> <!-- 关联接口 --> <property name="serviceInterface" value="com.mooing.hessian.DemoApi" /> </bean> </beans>
1) 如果客户端不使用spring,客户端代码如下
import java.net.MalformedURLException; import com.caucho.hessian.client.HessianProxyFactory; import com.mooing.hessian.DemoApi; public class ClientSpring { public static void main(String[] args) throws MalformedURLException, ClassNotFoundException { String url = "http://localhost:8080/jms1/remote/helloDemo"; HessianProxyFactory pf = new HessianProxyFactory(); DemoApi da = (DemoApi) pf.create(url); da.setName("test"); System.out.println(da.sayHello()); System.out.println(da.getUser()); } }
2) 如果客户端使用spring,需要导入上述jar,在客户端工程src目录下,新建一个remote-hessian.xml,这个文件可随意命名,内容为:
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd"> <beans> <bean id="helloDemo" class="org.springframework.remoting.caucho.HessianProxyFactoryBean"> <property name="serviceUrl"> <value> http://localhost:8080/jms1/remote/helloDemo </value> </property> <property name="serviceInterface"> <value>com.mooing.hessian.DemoApi</value> </property> </bean> </beans>
客户端代码
import java.net.MalformedURLException; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.caucho.hessian.client.HessianProxyFactory; import com.mooing.hessian.DemoApi; public class ClientSpring { public static void main(String[] args) throws MalformedURLException, ClassNotFoundException { // String url = "http://localhost:8080/jms1/remote/helloDemo"; // HessianProxyFactory pf = new HessianProxyFactory(); // DemoApi da = (DemoApi) pf.create(url); // da.setName("test"); // System.out.println(da.sayHello()); // System.out.println(da.getUser()); ApplicationContext context = new ClassPathXmlApplicationContext("remote-hessian.xml"); DemoApi da = (DemoApi) context.getBean("helloDemo"); da.setName("test spring"); System.out.println(da.sayHello()); System.out.println(da.getUser()); } }