从用户代理获取浏览器版本

// 来自 nowjava

import java.io.UnsupportedEncodingException;

import java.net.URLDecoder;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.StringTokenizer;


public class Main{

    

    public static String getBrowserVersionFromUserAgent(String userAgent,

            String browser) {

        if (StringUtil.isEmpty(browser))

            return "";

        if (StringUtil.isEmpty(userAgent))

            return "";

        userAgent = userAgent.toLowerCase();/**from N o w J a v a . c o m - 时  代  Java**/

        int length = userAgent.length();

        int begin = -1;


        String versionKey = browser;


        if (browser.equals("safari"))

            versionKey = "version";

        begin = userAgent.indexOf(versionKey);

        if (begin == -1)

            return "";

        begin = begin + versionKey.length();

        int end = begin + 2;

        for (int i = 2; i < 50; i++) {

            if ((begin + i) >= userAgent.length())

                break;

            char value = userAgent.charAt(begin + i);

            if (value == '/' || value == ';' || value ==