JSP中实现判断客户端手机类型并跳转到app下载页面

%@page import="java.util.regex.Matcher"%>
%@page import="java.util.regex.Pattern"%>
%@ page language="java" pageEncoding="UTF-8"%>
%!
// \b 是单词边界(连着的两个(字母字符 与 非字母字符) 之间的逻辑上的间隔),字符串在编译时会被转码一次,所以是 "\\b"
// \B 是单词内部逻辑间隔(连着的两个字母字符之间的逻辑上的间隔)

String androidReg = "\\bandroid|Nexus\\b";
String iosReg = "ip(hone|od|ad)";

Pattern androidPat = Pattern.compile(androidReg, Pattern.CASE_INSENSITIVE);
Pattern iosPat = Pattern.compile(iosReg, Pattern.CASE_INSENSITIVE);

public boolean likeAndroid(String userAgent){
	if(null == userAgent){
		userAgent = "";
	}
	// 匹配
	Matcher matcherAndroid = androidPat.matcher(userAgent);
	if(matcherAndroid.find()){
		return true;
	} else {
		return false;
	}
}
public boolean likeIOS(String userAgent){
	if(null == userAgent){
		userAgent = "";
	}
	// 匹配
	Matcher matcherIOS = iosPat.matcher(userAgent);
	if(matcherIOS.find()){
		return true;
	} else {
		return false;
	}
}

%>
%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

//
String userAgent = request.getHeader( "USER-AGENT" ).toLowerCase();
System.out.println("userAgent: "+userAgent);
if(null == userAgent){
	userAgent = "";
}
if(likeAndroid(userAgent)){
System.out.println("likeAndroid: "+true);
	response.sendRedirect("http://m.jb51.net/download.jsp?platform=android");
	return;
	//request.getRequestDispatcher("/download.html").forward(request,response);
} else if(likeIOS(userAgent)){
System.out.println("likeIOS: "+true);
	response.sendRedirect("http://itunes.apple.com/us/app/id714751061");
	return;
	//request.getRequestDispatcher("/index.html").forward(request,response);
}
%>
!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
html xmlns="http://www.w3.org/1999/xhtml">
head>
meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no">
title>下载客户端 - 永恒记忆/title>
link href="css/style.css" rel="stylesheet" type="text/css" />
/head>

body>
div class="p_down">
	div>
		a href="index.html">
		img src="images/p_logo.png" class="p_logo" />
		/a>
	/div> 
		
		a href="itms-services://?action=download-manifesturl=http://m.jb51.net/upload/client/yhjyios.plist" class="apple download">img src="images/p_down_apple.png" />/a>
		a href="http://m.jb51.net/download.jsp?platform=android" class="download">img src="images/p_down_and.png" />/a>
		
/div>
/body>
/html>