Hession使用简单示例

╰半夏微凉° 2022-08-23 13:45 169阅读 0赞

通过Hessian我们可以暴露服务端接口实现给远程客户端调用（比ejb简单），下面上例子

服务端：在eclipse中新建web工程

1.接口定义

IHelloService.java

public interface IHelloService \{  
    public String sayHello(String name);  
\}

2.接口实现

IHelloServiceImpl.java

public class IHelloServiceImpl implements IHelloService \{  
  
    @Override  
    public String sayHello(String name) \{  
        return "Hello "+name;  
    \}  
  
\}

3.web.xml定义

<?xml version="1.0" encoding="UTF-8" ?>  
<web-app version="3.0"     
    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\_3\_0.xsd">  
    <servlet>  
        <servlet-name>helloService</servlet-name>  
        <servlet-class>com.caucho.hessian.server.HessianServlet</servlet-class>  
        <init-param>  
            <param-name>home-class</param-name>  
            <param-value>com.wangbo.hello.IHelloServiceImpl</param-value>  
        </init-param>  
        <init-param>  
            <param-name>home-api</param-name>  
            <param-value>com.wangbo.hello.IHelloService</param-value>  
        </init-param>  
    </servlet>  
    <servlet-mapping>  
        <servlet-name>helloService</servlet-name>  
        <url-pattern>/hessian/HelloService</url-pattern>  
    </servlet-mapping>  
</web-app>

4.启动服务端

客户端实现

1.拷贝IHelloService接口

import java.net.MalformedURLException;  
import com.caucho.hessian.client.HessianProxyFactory;  
  
public class Test \{  
  
    /\*\*  
     \* @param args  
     \*/  
    public static void main(String\[\] args) \{

//testHelloService1();  
           testHelloService2();  
    \}  
  
    private static void testHelloService1() \{  
        String url = "http://localhost:8080/HessianServer//hessian/HelloService";    
           HessianProxyFactory factory = new HessianProxyFactory();    
           try \{  
               IHelloService helloService = (IHelloService)factory.create(IHelloService.class, url);  
                System.out.println(helloService.sayHello("Hesssian"));  
            \} catch (MalformedURLException e) \{  
                e.printStackTrace();  
            \}  
    \}  
      
    private static void testHelloService2() \{  
        String url = "http://localhost:8080/HessianServer//hessian/HelloService";    
           HessianProxyFactory factory = new HessianProxyFactory();    
           try \{  
               IHelloService helloService = (IHelloService)factory.create(url);  
                System.out.println(helloService.sayHello("Hesssian"));  
            \} catch (MalformedURLException e) \{  
                e.printStackTrace();  
            \} catch (ClassNotFoundException e) \{  
                e.printStackTrace();  
            \}     
    \}  
  
\}

注意:

1.如果使用factory.create(IHelloService.class, url);则web.xml中无需配置

<init-param>  
            <param-name>home-api</param-name>  
            <param-value>com.wangbo.hello.IHelloService</param-value>  
        </init-param>

2.如果使用factory.create(url);则web.xml必须配置

<init-param>  
            <param-name>home-api</param-name>  
            <param-value>com.wangbo.hello.IHelloService</param-value>  
        </init-param>

否则报ClassNotFoundException

3.如果使用public class IHelloServiceImpl extends HessianServlet implements IHelloService\{\}的方式，需要依赖servlet-api.jar，同时web.xml配置要做调整