Hessian和Burlap入門教程

一、簡介

    Hessian和Burlap是由Caucho Technology提供的基於HTTP協議的輕量級遠程服務解決方案。他們都致力於借助盡可能簡單那的API和通信協議來簡化Web服務。
    Hession和Burlap就如同一個事物的兩面，但是每一個解決方案都服務於略微不同的目的。Hession就像RMI一樣，使用二進制盡心客戶端和服務端的交互。但與其他二進制遠程調用技術（如，RMI）不同的是，它的二進制消息可以移植到其他開發語言中（如，PHP、Python、C++、C#）。Burlap是一種基於XML的遠程調用技術，這使得它可以自然而然的移植到任何能夠解析XML的語言上。正因為如此，Burlap比起Hessian的二進制格式而言有更強的可讀性。但，與其他基於XML的遠程技術（如，SOAP、XML-RPC）不同，Burlap的消息結構盡可能的簡單，不需要額外的外部定義語言（如，WSDL、IDL）。
    你可能想知道如何在Hession和Burlap之間抉擇，很大程度，他們是一樣的。唯一的區別在於Hession的消息似乎二進制的，在帶寬上更有優勢，而Burlap的消息是XML的，有更好的可讀性。
    由於Hessian和Burlap都是基於HTTP協議的，他們都解決了RMI所頭疼的防火牆滲透問題。但是當傳遞過來的RPC消息中包含序列化對象時，RMI就完勝Hessian和Burlap了。因為Hessian和Burlap都采用私有的序列化機制，如果數據模型非常復雜，那么Hessian和Burlap的序列化模型可能無法勝任。

二、Hession開發步驟

    1、編寫服務接口

package com.cnblogs.javalouvre.service;

public interface GreetService {

    String sayHello(String name);

}

    2、編寫服務實現類，須繼承自com.caucho.hessian.server.HessianServlet

package com.cnblogs.javalouvre.service;

import com.caucho.hessian.server.HessianServlet;

public class GreetServiceImpl extends HessianServlet implements GreetService {

    private static final long serialVersionUID = 1880738686281295739L;

    @Override
    public String sayHello(String name) {
        return "Hello " + name;
    }

}

    3、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">

  <servlet>
   <servlet-name>HessianServlet</servlet-name>
   <servlet-class>com.caucho.hessian.server.HessianServlet</servlet-class>
    <init-param>
      <param-name>home-class</param-name>
      <param-value>com.cnblogs.javalouvre.service.GreetServiceImpl</param-value>
    </init-param>
    <init-param>
      <param-name>home-api</param-name>
      <param-value>com.cnblogs.javalouvre.service.GreetService</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>

  <servlet-mapping>
    <servlet-name>HessianServlet</servlet-name>
    <url-pattern>/GreetService</url-pattern>
  </servlet-mapping>

  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>

</web-app>

    4、測試客戶端

package com.cnblogs.javalouvre.client;

import java.net.MalformedURLException;

import com.caucho.hessian.client.HessianProxyFactory;
import com.cnblogs.javalouvre.service.GreetService;

public class Client {

    public static void main(String[] args) {
        String url = "http://10.108.1.138:8080/Hessian/GreetService";

        try {
            GreetService service = (GreetService) (new HessianProxyFactory()).create(GreetService.class, url);
            System.out.println(service.sayHello("Jobs"));
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
    }

}

 

三、Burlap開發步驟

    1、編寫服務接口(同Hessian示例的接口)
    2、編寫服務實現類，須繼承自com.caucho.burlap.server.BurlapServlet

package com.cnblogs.javalouvre.service;

import com.caucho.burlap.server.BurlapServlet;

public class GreetServiceImpl extends BurlapServlet implements GreetService {

    @Override
    public String sayHello(String name) {
        return "Hello " + name;
    }

}

    3、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">

  <servlet>
   <servlet-name>GreetService</servlet-name>
   <servlet-class>com.cnblogs.javalouvre.service.GreetServiceImpl</servlet-class>
    <load-on-startup>1</load-on-startup>
  </servlet>

  <servlet-mapping>
    <servlet-name>GreetService</servlet-name>
    <url-pattern>/GreetService</url-pattern>
  </servlet-mapping>

  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>

</web-app>

    4、測試客戶端

package com.cnblogs.javalouvre.client;

import java.net.MalformedURLException;

import com.caucho.burlap.client.BurlapProxyFactory;
import com.cnblogs.javalouvre.service.GreetService;

public class Client {

    public static void main(String[] args) {
        String url = "http://10.108.1.138:8080/Burlap/GreetService";

        try {
            GreetService service = (GreetService) (new BurlapProxyFactory()).create(GreetService.class, url);
            System.out.println(service.sayHello("Jobs"));
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
    }

}