在Servlet中获取来源URL

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		request.setCharacterEncoding("utf-8");
		response.setContentType("text/html;charset=utf-8");
		PrintWriter out = response.getWriter();
		out.println(""-//W3C//DTD HTML 4.01 Transitional//EN\">");
		out.println("");
		out.println("  请求来源");
		out.println("  ");
		String fromURL = request.getHeader("Referer");      
		out.print("来源于："+fromURL);
		StringBuffer requestURL = request.getRequestURL();
		String queryString = request.getQueryString();
		if(queryString != null){
			requestURL .append("?").append(queryString);
		}
		out.print("请求："+requestURL.toString());
		out.println("  ");
		out.println("");
		out.flush();
		out.close();
	}

从代码中可以看出获取来源URL，是通过获取HTTP头的方式得到的,代码中String fromURL = request.getHeader("Referer");  语句。而request.getRequestURL()是获取请求的URL，不包括参数。request.getQueryString()用于获取参数信息。


以下附录在编程常要获取的,包括获取一些常用的HTTP头：

out.println("Protocol: " + request.getProtocol()); 
out.println("Scheme: " + request.getScheme()); 
out.println("Server Name: " + request.getServerName() ); 
out.println("Server Port: " + request.getServerPort()); 
out.println("Protocol: " + request.getProtocol()); 
out.println("Server Info: " + getServletConfig().getServletContext().getServerInfo()); 
out.println("Remote Addr: " + request.getRemoteAddr()); 
out.println("Remote Host: " + request.getRemoteHost()); 
out.println("Character Encoding: " + request.getCharacterEncoding()); 
out.println("Content Length: " + request.getContentLength()); 
out.println("Content Type: "+ request.getContentType()); 
out.println("Auth Type: " + request.getAuthType()); 
out.println("HTTP Method: " + request.getMethod()); 
out.println("Path Info: " + request.getPathInfo()); 
out.println("Path Trans: " + request.getPathTranslated()); 
out.println("Query String: " + request.getQueryString()); 
out.println("Remote User: " + request.getRemoteUser()); 
out.println("Session Id: " + request.getRequestedSessionId()); 
out.println("Request URI: " + request.getRequestURI()); 
out.println("Servlet Path: " + request.getServletPath()); 
out.println("Accept: " + request.getHeader("Accept")); 
out.println("Host: " + request.getHeader("Host")); 
out.println("Referer : " + request.getHeader("Referer")); 
out.println("Accept-Language : " + request.getHeader("Accept-Language")); 
out.println("Accept-Encoding : " + request.getHeader("Accept-Encoding")); 
out.println("User-Agent : " + request.getHeader("User-Agent")); 
out.println("Connection : " + request.getHeader("Connection")); 
out.println("Cookie : " + request.getHeader("Cookie")); 
out.println("Created : " + session.getCreationTime()); 
out.println("LastAccessed : " + session.getLastAccessedTime());