如何获取.MSG文件的MIME类型？

Question

我试过这些方法来查找文件的MIME类型......

Path source = Paths
                .get("C://Users/akash/Desktop/FW Internal release of MSTClient-Server5.02.04_24.msg");
        System.out.println(Files.probeContentType(source));

上面的代码返回 null...
如果我使用Apache的TIKA API来获取MIME类型,那么它将它作为text/plain ...

但我希望结果如此 application/vnd.ms-outlook

UPDATE

我也使用MIME-Util.jar如下代码...

MimeUtil2 mimeUtil = new MimeUtil2();
        mimeUtil.registerMimeDetector("eu.medsea.mimeutil.detector.MagicMimeMimeDetector");
        RandomAccessFile file1 = new RandomAccessFile(
                "C://Users/akash/Desktop/FW Internal release of MSTClient-Server5.02.04_24.msg",
                "r");
        System.out.println(file1.length());
        byte[] file = new byte[624128];
        file1.read(file, 0, 624128);
        String mimeType = MimeUtil2.getMostSpecificMimeType(mimeUtil.getMimeTypes(file)).toString();

这给了我输出 application/msword

更新:

Tika API超出了范围,因为它太大而无法包含在项目中......

那么如何找到MIME类型？

Answer 1

我尝试了一些可能的方法,并使用tika给出你期望的结果,我没有看到你使用的代码,所以我不能仔细检查它.

我尝试了不同的方法,而不是全部在代码片段中:

1. Java 7 Files.probeContentType(path)
2. URLConnection 从文件名和内容类型猜测的mime检测
3. JDK 6 JAF API javax.activation.MimetypesFileTypeMap
4. MimeUtil与MimeDetector我找到的所有可用子类
5. 阿帕奇蒂卡
6. Apache POI暂存器

这里的测试类:

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.net.URLConnection;
import java.util.Collection;

import javax.activation.MimetypesFileTypeMap;

import org.apache.tika.detect.Detector;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.mime.MediaType;
import org.apache.tika.parser.AutoDetectParser;

import eu.medsea.mimeutil.MimeUtil;

public class FindMime {

    public static void main(String[] args) {
        File file = new File("C:\\Users\\qwerty\\Desktop\\test.msg");

        System.out.println("urlConnectionGuess " + urlConnectionGuess(file));

        System.out.println("fileContentGuess " + fileContentGuess(file));

        MimetypesFileTypeMap mimeTypesMap = new MimetypesFileTypeMap();

        System.out.println("mimeTypesMap.getContentType " + mimeTypesMap.getContentType(file));

        System.out.println("mimeutils " + mimeutils(file));

        System.out.println("tika " + tika(file));

    }

    private static String mimeutils(File file) {
        try {
            MimeUtil.registerMimeDetector("eu.medsea.mimeutil.detector.MagicMimeMimeDetector");
            MimeUtil.registerMimeDetector("eu.medsea.mimeutil.detector.ExtensionMimeDetector");
//          MimeUtil.registerMimeDetector("eu.medsea.mimeutil.detector.OpendesktopMimeDetector");
            MimeUtil.registerMimeDetector("eu.medsea.mimeutil.detector.WindowsRegistryMimeDetector");
//          MimeUtil.registerMimeDetector("eu.medsea.mimeutil.detector.TextMimeDetector");
            InputStream is = new BufferedInputStream(new FileInputStream(file));
            Collection<?> mimeTypes = MimeUtil.getMimeTypes(is);
            return mimeTypes.toString();
        } catch (Exception e) {
            // TODO: handle exception
        }
        return null;
    }

    private static String tika(File file) {
        try {
            InputStream is = new BufferedInputStream(new FileInputStream(file));
            AutoDetectParser parser = new AutoDetectParser();
            Detector detector = parser.getDetector();
            Metadata md = new Metadata();
            md.add(Metadata.RESOURCE_NAME_KEY, "test.msg");
            MediaType mediaType = detector.detect(is, md);
            return mediaType.toString();
        } catch (Exception e) {
            // TODO: handle exception
        }
        return null;
    }

    private static String urlConnectionGuess(File file) {
        String mimeType = URLConnection.guessContentTypeFromName(file.getName());
        return mimeType;
    }

    private static String fileContentGuess(File file) {
        try {
            InputStream is = new BufferedInputStream(new FileInputStream(file));
            return URLConnection.guessContentTypeFromStream(is);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

}

这是输出:

urlConnectionGuess null
fileContentGuess null
mimeTypesMap.getContentType application/octet-stream
mimeutils application/msword,application/x-hwp
tika application/vnd.ms-outlook

更新后我添加了这个方法来测试Tika的其他方法:

private static void tikaMore(File file) {
    Tika defaultTika = new Tika();
    Tika mimeTika = new Tika(new MimeTypes());
    Tika typeTika = new Tika(new TypeDetector());
    try {
        System.out.println(defaultTika.detect(file));
        System.out.println(mimeTika.detect(file));
        System.out.println(typeTika.detect(file));
    } catch (Exception e) {
        // TODO: handle exception
    }
}

使用没有扩展名的msg文件进行测试:

application/vnd.ms-outlook
application/octet-stream
application/octet-stream

使用重命名为msg的txt文件进行测试:

text/plain
text/plain
application/octet-stream

在这种情况下,使用空构造函数的最简单方法似乎是最可靠的.

更新您可以使用Apache POI暂存器创建自己的检查器,例如,这是获取消息的mime的简单实现,如果文件格式不正确(通常org.apache.poi.poifs.filesystem.NotOLE2FileException: Invalid header signature),则为null :

import org.apache.poi.hsmf.MAPIMessage;

public class PoiMsgMime {

    public String getMessageMime(String fileName) {
        try {
            new MAPIMessage(fileName);
            return "application/vnd.ms-outlook";
        } catch (Exception e) {
            return null;
        }
    }
}