从返回文件名获取内容类型

//package com.nowjava;
/**
来 自 nowjava
**/


public class Main {

    public static void main(String[] argv) throws Exception {

        String returnFileName = "nowjava.com";

        System.out.println(getContentType(returnFileName));

    }


    public static String getContentType(String returnFileName) {

        String contentType = "application/octet-stream";

        if (returnFileName.lastIndexOf(".") < 0)

            return contentType;

        returnFileName = returnFileName.toLowerCase();

        returnFileName = returnFileName.substring(returnFileName

                .lastIndexOf(".") + 1);


        if (returnFileName.equals("html") || returnFileName.equals("htm")

                || returnFileName.equals("shtml")) {

            contentType = "text/html";// 来自 时代Java公众号 - nowjava.com

        } else if (returnFileName.equals("css")) {

            contentType = "text/css";

        } else if (returnFileName.equals("xml")) {

            contentType = "text/xml";

        } else if (returnFileName.equals("gif")) {

            contentType = "image/gif";

        } else if (returnFileName.equals("jpeg")

                || returnFileName.equals("jpg")) {

            contentType = "image/jpeg";

        } else if (returnFileName.equals("js")) {

            contentType = "application/x-javascript";

        } else if (returnFileName.equals("atom")) {

            contentType = "application/atom+xml";

        } else if (returnFileName.equals("rss")) {

            contentType = "application/rss+xml";

        } else if (returnFileName.equals("mml")) {

            contentType = "text/mathml";

        } else if (returnFileName.equals("txt")) {

            contentType = "text/plain";

        } else if (returnFileName.equals("jad")) {

            contentType = "text/vnd.sun.j2me.app-descriptor";

        } else if (returnFileName.equals("wml")) {

            contentType = "text/vnd.wap.wml";

        } else if (returnFileName.equals("htc")) {

            contentType = "text/x-component";

        } else if (returnFileName.equals("png")) {

            contentType = "image/png";

        } else if (returnFileName.equals("tif")

                || returnFileName.equals("tiff")) {

            contentType = "image/tiff";

        } else if (returnFileName.equals("wbmp")) {

            contentType = "image/vnd.wap.wbmp";

        } else if (returnFileName.equals("ico")) {

            contentType = "image/x-icon";

        } else if (returnFileName.equals("jng")) {

            contentType = "image/x-jng";

        } else if (returnFileName.equals("bmp")) {

            contentType = "image/x-ms-bmp";

        } else if (returnFileName.equals("svg")) {

            contentType = "image/svg+xml";

        } else if (returnFileName.equals("jar")

                || returnFileName.equals("var")

                || returnFileName.equals("ear")) {

            contentType = "application/java-archive";

        } else if (returnFileName.equals("doc")) {

            contentType = "application/msword";

        } else if (returnFileName.equals("pdf")) {

            contentType = "application/pdf";

        } else if (returnFileName.equals("rtf")) {

            contentType = "application/rtf";

        } else if (returnFileName.equals("xls")) {

            contentType = "application/vnd.ms-excel";

        } else if (returnFileName.equals("ppt")) {

            contentType = "application/vnd.ms-powerpoint";

        } else if (returnFileName.equals("7z")) {

            contentType = "application/x-7z-compressed";

        } else if (returnFileName.equals("rar")) {

            contentType = "application/x-rar-compressed";

        } else if (returnFileName.equals("swf")) {

            contentType = "application/x-shockwave-flash";

        } else if (returnFileName.equals("rpm")) {

            contentType = "application/x-redhat-package-manager";

        } else if (returnFileName.equals("der")

                || returnFileName.equals("pem")

                || returnFileName.equals("crt")) {

            contentType = "application/x-x509-ca-cert";

        } else if (returnFileName.equals("xhtml")) {

            contentType = "application/xhtml+xml";

        } else if (returnFileName.equals("zip")) {

            contentType = "application/zip";

        } else if (returnFileName.equals("mid")

                || returnFileName.equals("midi")

                || returnFileName.equals("kar")) {

            contentType = "audio/midi";

        } else if (returnFileName.equals("mp3")) {

            contentType = "audio/mpeg";

        } else if (returnFileName.equals("ogg")) {

            contentType = "audio/ogg";

        } else if (returnFileName.equals("m4a")) {

            contentType = "audio/x-m4a";

        } else if (returnFileName.equals("ra")) {

            contentType = "audio/x-realaudio";

        } else if (returnFileName.equals("3gpp")

                || returnFileName.equals("3gp")) {

            contentType = "video/3gpp";

        } else if (returnFileName.equals("mp4")) {

            contentType = "video/mp4";

        } else