webstart.java

用Java开发的、实现类似Visio功能的应用程序源码

/**
 *    $Id:WebStart.java $
 *
 *    Copyright 2004 ~ 2005  JingFei International Cooperation LTD. All rights reserved. *
 */
package com.jfimagine.jfdraw.webstart;


import java.io.PrintWriter;
import java.io.IOException;

import javax.servlet.*;
import javax.servlet.http.*;


 /**
 * WebStart class is used to create a dynamic jnlp output for web start JFDraw.
 *
 * @author     CookieMaker    
 *
 * @version $Revision: 1.2.0 $
 */  
public class WebStart extends HttpServlet {
	
	
	private ServletConfig config;
	public void init (ServletConfig config) throws ServletException
	{
		super.init(config);
          	this.config = config;
	}
			
	protected void doGet(HttpServletRequest request, HttpServletResponse response) 
    		throws ServletException, IOException {
	
		//Get arguments from http request
                String fileName 	=request.getParameter("fileName");
                String fileName2 	=request.getParameter("fileName2");
                String fileName3 	=request.getParameter("fileName3");
                String fileName4 	=request.getParameter("fileName4");
                
                int httpHeadLen		="http://".length();
                
                //prepare the content of JNLP file.
                StringBuffer buf	=new StringBuffer();
                buf.append("<?xml version=\"1.0\" encoding=\"utf-8\"?>"); 
                buf.append("\n");
                
		buf.append("<jnlp spec=\"1.0+\"  codebase=\"http://www.jfimagine.com/webstart\" >"); 
		buf.append("\n");
		
 		buf.append("<information>"); 				
 		buf.append("\n");
 		
     		buf.append("<title>JFDraw Web start Solution</title>");  	
     		buf.append("\n");
     		
     		buf.append("<vendor>www.jfimagine.com</vendor>");	
     		buf.append("\n");
     		
     		buf.append("<homepage href=\"http://www.jfimagine.com\"/>");  	
     		buf.append("\n");
     		
     		buf.append("<description>JFDraw Web Start Solution</description>");	
     		buf.append("\n");
     		
     		buf.append("<description kind=\"short\">A vector graphs application and library package</description>");  
     		buf.append("\n");
     		
     		buf.append("<icon href=\"jfimagine.small.jpg\"/>");  	buf.append("\n");
     		
     		buf.append("<offline-allowed/>");			buf.append("\n");
     		
 		buf.append("</information>");				buf.append("\n");
 		
		buf.append("<resources>");				buf.append("\n");
		
    		buf.append("<j2se version=\"1.4+\" />");		buf.append("\n");
    		
    		buf.append("<jar href=\"jfdraw_webstart.jar\"/>");	buf.append("\n");
    		
		buf.append("</resources>");				buf.append("\n");
		
		buf.append("<application-desc main-class=\"JFDraw\">"); buf.append("\n");
		
		
		//package the parameters to <argument> pairs.
		if (fileName!=null && fileName.length()>httpHeadLen){
			buf.append("<argument>"+fileName+"</argument>");	
			buf.append("\n");
		}
		if (fileName2!=null && fileName2.length()>httpHeadLen){
			buf.append("<argument>"+fileName2+"</argument>");	
			buf.append("\n");
		}
		if (fileName3!=null && fileName3.length()>httpHeadLen){
			buf.append("<argument>"+fileName3+"</argument>");	
			buf.append("\n");
		}
		if (fileName4!=null && fileName4.length()>httpHeadLen){
			buf.append("<argument>"+fileName4+"</argument>");	
			buf.append("\n");
		}
		
		buf.append("</application-desc>");

		buf.append("<security>");				buf.append("\n");
     		buf.append("<all-permissions/>");			buf.append("\n");
		buf.append("</security>");				buf.append("\n");
		buf.append("</jnlp>");					buf.append("\n");

		
		//output the JNLP file.
		PrintWriter out = response.getWriter(); 
		//jnlp content type
		response.setContentType("application/x-java-jnlp-file");
		//set immediate expire time to force browser to fetch jnlp content each time.
		response.setHeader("Expires", "0"); 
		response.addDateHeader("Date", java.util.Calendar.getInstance().getTime().getTime());
		response.addDateHeader("Last-Modified", java.util.Calendar.getInstance().getTime().getTime());
		out.println(buf.toString());
		out.close();
	}


	protected void doPost(HttpServletRequest request, HttpServletResponse response) 
    		throws ServletException, IOException {
  		doGet(request, response);
	}

}