hidejsservlet.java

深入JavaWeb开发内幕核心基础书中源码

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class HideJSServlet extends HttpServlet
{
	public void service(HttpServletRequest request,
		HttpServletResponse response) throws ServletException, IOException
	{
		response.setContentType("text/javascript;charset=GB2312");
		response.setDateHeader("Expires",0);
		response.setHeader("Cache-Control","no-cache"); 
		response.setHeader("Pragma","no-cache"); 
		
		PrintWriter out = response.getWriter();
		String referrer = request.getHeader("referer");
		String sitePart = "http://" + request.getServerName();
		if(referrer!=null && referrer.startsWith(sitePart))
		{
			//向客户端输出javascript的document.write(...)语句
			out.println(
				"document.write('假设这是很多重要的Javascript代码的执行结果');");
		}
	}
}