check Browser Version

checkBrowserVersion.jsp

<%
    boolean showPopup = false;
    try {
        String userAgent = request.getHeader("user-agent");
        String browserVersion = "UNKNOWNVERSION";
        String majorVersion = "1";
        int validVersion = 1;
        String user = userAgent.toLowerCase();
        if (userAgent != null) {
            if (user.contains("msie")) {
                String substring = userAgent.substring(userAgent.indexOf("MSIE")).split(";")[0];
                browserVersion = substring.split(" ")[1];
                validVersion = 10;
            } else if (user.contains("safari") && user.contains("version")) {
                browserVersion = (userAgent.substring(userAgent.indexOf("Version")).split(" ")[0]).split("/")[1];
                validVersion = 7;
            } else if (user.contains("opr") || user.contains("opera")) {
                validVersion = 12;
                if (user.contains("opera")) {
                    browserVersion = (userAgent.substring(userAgent.indexOf("Version")).split(" ")[0]).split("/")[1];
                } else if (user.contains("opr")) {
                    String substring = userAgent.substring(userAgent.indexOf("OPR"));
                    String Info[] = (substring.split(" ")[0]).split("/");
                    browserVersion = Info[1];
                }
            } else if (user.contains("chrome")) {
                String substring = userAgent.substring(userAgent.indexOf("Chrome"));
                String Info[] = (substring.split(" ")[0]).split("/");
                browserVersion = Info[1];
                validVersion = 37;
            } else if ((user.indexOf("mozilla/7.0") > -1) || (user.indexOf("netscape6") != -1) || (user.indexOf("mozilla/4.7") != -1)
                    || (user.indexOf("mozilla/4.78") != -1) || (user.indexOf("mozilla/4.08") != -1) || (user.indexOf("mozilla/3") != -1)) {
                browserVersion = "UNKNOWNVERSION";
            } else if (user.contains("firefox")) {
                String substring = userAgent.substring(userAgent.indexOf("Firefox"));
                String Info[] = (substring.split(" ")[0]).split("/");
                browserVersion = Info[1];
                validVersion = 25;
            } else if (user.contains("rv")) {
                String substring = userAgent.substring(userAgent.indexOf("rv"), userAgent.length());
                browserVersion = substring.substring(substring.indexOf(":") + 1, substring.indexOf(")"));
                validVersion = 10;
            } else {
                browserVersion = "UNKNOWNVERSION";
            }
            if (!"UNKNOWNVERSION".equals(browserVersion)) {
                if (browserVersion.contains(".")) {
                    majorVersion = (browserVersion.substring(0, browserVersion.indexOf("."))).trim();
                }
            }
            int version = Integer.parseInt(majorVersion.trim());
            if (validVersion > version) {
                showPopup = true;
            }
        }
    } catch (Exception e) {
    }
%>
<script type="text/javascript" language="javascript">
    var popup =<%=showPopup%>;
    if (popup) {
        if (confirm("Invalid Browser!") == true) {
            x = "You pressed OK!";
            //Redirect to New Page
            window.location.replace("http://browsehappy.com/");
        } else {
            x = "You pressed Cancel!";
        }
    }
</script>