Hessian初體驗－Jemmy Walker

沒想到漏記了這個技術，Hessian是Remoting技術之一，有別web services是binary，故速度較快，源自Spring，底下有個小小Sample誌之：

和其他技術一樣，Interface與Implement分離而作，是故先定義Interface：

public interface Hello {
public String hello(String name);
}

下面是放在server上的Implement

public class HelloImpl implements Hello {
    public String hello(String name) {
  System.out.println("Hello! " + name);
        return "hello " + name + " welcome to Hessian";
    }
}

在web.xml的設定如下：

<web-app>
<servlet>
  <servlet-name>hessianService</servlet-name>
  <servlet-class>
   com.caucho.hessian.server.HessianServlet
  </servlet-class>
  <load-on-startup>1</load-on-startup>
  <init-param>
   <param-name>service-class</param-name>
   <param-value>HelloImpl</param-value>
        </init-param>
</servlet>

<servlet-mapping>
<servlet-name>hessianService</servlet-name>
<url-pattern>/hessianService</url-pattern>
</servlet-mapping>
</web-app>

在WEB-INF/lib只需放一個jar：hessian-3.1.2.jar (最新已到3.1.5了)

Client 端程式也只需上述的Jar，呼叫如下：

import com.caucho.hessian.client.*;
public class HessianClient {
    public static void main(String []args) throws Exception   {
           String url = "http://localhost:8888/reg/hessianService";　// 假定web context為reg
           HessianProxyFactory factory = new HessianProxyFactory();
           Hello d = (Hello) factory.create(Hello.class, url);
           System.out.println("Hessian: " + d.hello("yeeku"));
    }
}
執行批次如下：

java -classpath .;Hello.class;hessian-3.1.2.jar HessianClient.class