Mime Type（Content-Type）

MIME Type介绍 Content-Type 各种定义

多用途互联网邮件扩展（MIME，Multipurpose Internet Mail Extensions）是一个互联网标准，它扩展了电子邮件标准，使其能够支持非ASCII字符、二进制格式附件等多种格式的邮件消息。在万维网中使用的HTTP协议中也使用了MIME的框架，标准被扩展为互联网媒体类型。通常来说，浏览器通过MIME Type区分不同的媒体资源。目前版本：1.0。

MIME Type是经由IETF组织协商，以RFC形式作为建议标准发布在网上，通常只有一些在互联网上获得广泛应用的格式才会获得一个 MIME Type，如果是某个客户端自己定义的格式，一般只能以application/x- 开头。处理本地的文件，在没有人告诉浏览器某个文件的MIME Type的情况下，浏览器也会做一些默认的处理，这可能和在操作系统中给文件配置的MIME Type有关。

在HTTP中，MIME Type类型被定义在Content-Type header中，每个MIME类型由3部分组成：Content-Type: [type]/[subtype]，前者是数据大类别，后者定义具体的种类。

通过文件扩展名获取ContentType

import lombok.Getter;
import org.apache.commons.lang3.StringUtils;

/**
 * 通过文件扩展名获取ContentType
 */
@Getter
public enum MimeTypeEnum {

    AAC("acc", "AAC音频", "audio/aac"),
    ABW("abw", "AbiWord文件", "application/x-abiword"),
    ARC("arc", "存档文件", "application/x-freearc"),
    AVI("avi", "音频视频交错格式", "video/x-msvideo"),
    AZW("azw", "亚马逊Kindle电子书格式", "application/vnd.amazon.ebook"),
    BIN("bin", "任何类型的二进制数据", "application/octet-stream"),
    BMP("bmp", "Windows OS / 2位图图形", "image/bmp"),
    BZ("bz", "BZip存档", "application/x-bzip"),
    BZ2("bz2", "BZip2存档", "application/x-bzip2"),
    CSH("csh", "C-Shell脚本", "application/x-csh"),
    CSS("css", "级联样式表（CSS）", "text/css"),
    CSV("csv", "逗号分隔值（CSV）", "text/csv"),
    DOC("doc", "微软Word文件", "application/msword"),
    DOCX("docx", "Microsoft Word（OpenXML）", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"),
    EOT("eot", "MS Embedded OpenType字体", "application/vnd.ms-fontobject"),
    EPUB("epub", "电子出版物（EPUB）", "application/epub+zip"),
    GZ("gz", "GZip压缩档案", "application/gzip"),
    GIF("gif", "图形交换格式（GIF）", "image/gif"),
    HTM("htm", "超文本标记语言（HTML）", "text/html"),
    HTML("html", "超文本标记语言（HTML）", "text/html"),
    ICO("ico", "图标格式", "image/vnd.microsoft.icon"),
    ICS("ics", "iCalendar格式", "text/calendar"),
    JAR("jar", "Java存档", "application/java-archive"),
    JPEG("jpeg", "JPEG图像", "image/jpeg"),
    JPG("jpg", "JPEG图像", "image/jpeg"),
    JS("js", "JavaScript", "text/javascript"),
    JSON("json", "JSON格式", "application/json"),
    JSONLD("jsonld", "JSON-LD格式", "application/ld+json"),
    MID("mid", "乐器数字接口（MIDI）", "audio/midi"),
    MIDI("midi", "乐器数字接口（MIDI）", "audio/midi"),
    MJS("mjs", "JavaScript模块", "text/javascript"),
    MP3("mp3", "MP3音频", "audio/mpeg"),
    MPEG("mpeg", "MPEG视频", "video/mpeg"),
    MPKG("mpkg", "苹果安装程序包", "application/vnd.apple.installer+xml"),
    ODP("odp", "OpenDocument演示文稿文档", "application/vnd.oasis.opendocument.presentation"),
    ODS("ods", "OpenDocument电子表格文档", "application/vnd.oasis.opendocument.spreadsheet"),
    ODT("odt", "OpenDocument文字文件", "application/vnd.oasis.opendocument.text"),
    OGA("oga", "OGG音讯", "audio/ogg"),
    OGV("ogv", "OGG视频", "video/ogg"),
    OGX("ogx", "OGG", "application/ogg"),
    OPUS("opus", "OPUS音频", "audio/opus"),
    OTF("otf", "otf字体", "font/otf"),
    PNG("png", "便携式网络图形", "image/png"),
    PDF("pdf", "Adobe 可移植文档格式（PDF）", "application/pdf"),
    PHP("php", "php", "application/x-httpd-php"),
    PPT("ppt", "Microsoft PowerPoint", "application/vnd.ms-powerpoint"),
    PPTX("pptx", "Microsoft PowerPoint（OpenXML）", "application/vnd.openxmlformats-officedocument.presentationml.presentation"),
    RAR("rar", "RAR档案", "application/vnd.rar"),
    RTF("rtf", "富文本格式", "application/rtf"),
    SH("sh", "Bourne Shell脚本", "application/x-sh"),
    SVG("svg", "可缩放矢量图形（SVG）", "image/svg+xml"),
    SWF("swf", "小型Web格式（SWF）或Adobe Flash文档", "application/x-shockwave-flash"),
    TAR("tar", "磁带存档（TAR）", "application/x-tar"),
    TIF("tif", "标记图像文件格式（TIFF）", "image/tiff"),
    TIFF("tiff", "标记图像文件格式（TIFF）", "image/tiff"),
    TS("ts", "MPEG传输流", "video/mp2t"),
    TTF("ttf", "ttf字体", "font/ttf"),
    TXT("txt", "文本（通常为ASCII或ISO 8859- n", "text/plain"),
    VSD("vsd", "微软Visio", "application/vnd.visio"),
    WAV("wav", "波形音频格式", "audio/wav"),
    WEBA("weba", "WEBM音频", "audio/webm"),
    WEBM("webm", "WEBM视频", "video/webm"),
    WEBP("webp", "WEBP图像", "image/webp"),
    WOFF("woff", "Web开放字体格式（WOFF）", "font/woff"),
    WOFF2("woff2", "Web开放字体格式（WOFF）", "font/woff2"),
    XHTML("xhtml", "XHTML", "application/xhtml+xml"),
    XLS("xls", "微软Excel", "application/vnd.ms-excel"),
    XLSX("xlsx", "微软Excel（OpenXML）", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"),
    XML("xml", "XML", "application/xml"),
    XUL("xul", "XUL", "application/vnd.mozilla.xul+xml"),
    ZIP("zip", "ZIP", "application/zip"),
    MIME_3GP("3gp", "3GPP audio/video container", "video/3gpp"),
    MIME_3GP_WITHOUT_VIDEO("3gp", "3GPP audio/video container doesn"t contain video", "audio/3gpp2"),
    MIME_3G2("3g2", "3GPP2 audio/video container", "video/3gpp2"),
    MIME_3G2_WITHOUT_VIDEO("3g2", "3GPP2 audio/video container  doesn"t contain video", "audio/3gpp2"),
    MIME_7Z("7z", "7-zip存档", "application/x-7z-compressed");

    //扩展名
    private final String extension;
    //说明
    private final String explain;
    //contentType/mime类型
    private final String mimeType;

    /**
     * @param extension 上传的文件扩展名
     * @param explain   类型说明
     * @param mimeType  Mime对应的类型
     */
    MimeTypeEnum(String extension, String explain, String mimeType) {
        this.extension = extension;
        this.explain = explain;
        this.mimeType = mimeType;
    }

    /**
     * 通过扩展名获取枚举类型
     *
     * @param extension 扩展名
     * @return 枚举类
     */
    public static MimeTypeEnum getByExtension(String extension) {
        if (StringUtils.isEmpty(extension)) {
            return null;
        }
        for (MimeTypeEnum typesEnum : MimeTypeEnum.values()) {
            if (extension.equals(typesEnum.getExtension())) {
                return typesEnum;
            }
        }
        return null;
    }

    /**
     * Content-Type常用对照
     * 根据后缀获取Mime
     *
     * @param fileType 扩展名
     * @return mime类型
     */
    public static String getContentType(String fileType) {
        MimeTypeEnum mimeTypeEnum = MimeTypeEnum.getByExtension(fileType);
        if (mimeTypeEnum != null) {
            return mimeTypeEnum.getMimeType();
        }
        return "application/octet-stream";
    }

}

根据文件获取MimeType的几种方式

    cn.hutool
    hutool-all
    5.6.5



    org.apache.commons
    commons-lang3
    3.7



    com.alibaba
    fastjson
    1.2.79


    net.sf.jmimemagic
    jmimemagic
    0.1.4

import cn.hutool.core.io.FileUtil;
import net.sf.jmimemagic.*;

import javax.activation.MimetypesFileTypeMap;
import java.io.File;
import java.io.IOException;
import java.net.FileNameMap;
import java.net.URLConnection;
import java.nio.file.Files;

public class MimeTypeDemo {

    public static void main(String[] args) {
        File file = FileUtil.file("d:/001.jpg");
        // 第一种方式
        String mimeType1 = "";
        try {
            Magic parser = new Magic();
            MagicMatch match = parser.getMagicMatch(file, false);
            mimeType1 = match.getMimeType();
        } catch (MagicParseException e) {
            e.printStackTrace();
        } catch (MagicMatchNotFoundException e) {
            e.printStackTrace();
        } catch (MagicException e) {
            e.printStackTrace();
        }
        System.out.println("第一种方式: " + mimeType1);
        // 第二种方式
        String mimeType2 = new MimetypesFileTypeMap().getContentType(file);
        System.out.println("第二种方式: " + mimeType2);
        // 第三种方式
        String mimeType3 = "";
        try {
            mimeType3 = Files.probeContentType(file.toPath());
        } catch (IOException e) {
            e.printStackTrace();
        }
        System.out.println("第三种方式: " + mimeType3);
        //  第四种方式
        FileNameMap fileNameMap = URLConnection.getFileNameMap();
        String mimeType4 = fileNameMap.getContentTypeFor(file.getParent());
        System.out.println("第四种方式: " + mimeType4);

        // 通过文件扩展名获取ContentType
        MimeTypeEnum mimeTypeEnum = MimeTypeEnum.getByExtension("jpg");
        System.out.println(mimeTypeEnum.getExplain()+ " , "+mimeTypeEnum.getMimeType()+ " , "+mimeTypeEnum.getExtension());
    }

}