java获取访问者浏览器_java 通过userAgent获取访问者的操作系统与浏览器

StringBuilder userAgent = new StringBuilder("[");         userAgent.append(request.getHeader("User-Agent"));         userAgent.append("]");         int indexOfMac = userAgent.indexOf("Mac OS X");         int indexOfWindows = userAgent.indexOf("Windows NT");         int indexOfIE = userAgent.indexOf("MSIE");         int indexOfIE11 = userAgent.indexOf("rv:");         int indexOfFF = userAgent.indexOf("Firefox");         int indexOfSogou = userAgent.indexOf("MetaSr");         int indexOfChrome = userAgent.indexOf("Chrome");         int indexOfSafari = userAgent.indexOf("Safari");         boolean isMac = indexOfMac > 0;         boolean isWindows = indexOfWindows > 0;         boolean isLinux = userAgent.indexOf("Linux") > 0;         boolean containIE = indexOfIE > 0 || (isWindows && (indexOfIE11 > 0));         boolean containFF = indexOfFF > 0;         boolean containSogou = indexOfSogou > 0;         boolean containChrome = indexOfChrome > 0;         boolean containSafari = indexOfSafari > 0;         String browser = "";         if (containSogou) {             if (containIE) {                 browser = "搜狗" + userAgent.substring(indexOfIE, indexOfIE + "MSIE x.x".length());             } else if (containChrome) {                 browser = "搜狗" + userAgent.substring(indexOfChrome, indexOfChrome + "Chrome/xx".length());             }         } else if (containChrome) {             browser = userAgent.substring(indexOfChrome, indexOfChrome + "Chrome/xx".length());         } else if (containSafari) {             int indexOfSafariVersion = userAgent.indexOf("Version");             browser = "Safari "                     + userAgent.substring(indexOfSafariVersion, indexOfSafariVersion + "Version/x.x.x".length());         } else if (containFF) {             browser = userAgent.substring(indexOfFF, indexOfFF + "Firefox/xx".length());         } else if (containIE) {             if (indexOfIE11 > 0) {                 browser = "MSIE 11";             } else {                 browser = userAgent.substring(indexOfIE, indexOfIE + "MSIE x.x".length());             }         }         String os = "";         if (isMac) {             os = userAgent.substring(indexOfMac, indexOfMac + "MacOS X xxxx".length());         } else if (isLinux) {             os = "Linux";         } else if (isWindows) {             os = "Windows ";             String version = userAgent.substring(indexOfWindows + "Windows NT".length(), indexOfWindows                     + "Windows NTx.x".length());             if ("5.0".equals(version.trim())) {                 os += "2000";             } else if ("5.1".equals(version.trim())) {                 os += "XP";             } else if ("5.2".equals(version.trim())) {                 os += "2003";             } else if ("6.0".equals(version.trim())) {                 os += "Vista";             } else if ("6.1".equals(version.trim())) {                 os += "7";             } else if ("6.2".equals(version.trim())) {                 os += "8";             } else if ("6.3".equals(version.trim())) {                 os += "8.1";             }         }         System.out.println("系统：" + os + ",浏览器：" + browser);