java库从文件内容中查找mime类型[重复]

Question

这个问题已经在这里有了答案：

• 在Java中获取文件的Mime类型 21答案

我正在寻找一个Java库，它通过查看文件内容（字节数组）来告诉您mime类型。 我发现该项目使用jmimemagic，并且不再支持较新的文件类型（例如MS Word docx格式），因为它现在（从2006年开始）处于非活动状态。

Answer 1

对于也需要最常用的办公格式（并且不使用Apache Tika）的人可能有用：

public class MimeTypeUtils {

    private static final Map<String, String> fileExtensionMap;

    static {
        fileExtensionMap = new HashMap<String, String>();
        // MS Office
        fileExtensionMap.put("doc", "application/msword");
        fileExtensionMap.put("dot", "application/msword");
        fileExtensionMap.put("docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document");
        fileExtensionMap.put("dotx", "application/vnd.openxmlformats-officedocument.wordprocessingml.template");
        fileExtensionMap.put("docm", "application/vnd.ms-word.document.macroEnabled.12");
        fileExtensionMap.put("dotm", "application/vnd.ms-word.template.macroEnabled.12");
        fileExtensionMap.put("xls", "application/vnd.ms-excel");
        fileExtensionMap.put("xlt", "application/vnd.ms-excel");
        fileExtensionMap.put("xla", "application/vnd.ms-excel");
        fileExtensionMap.put("xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        fileExtensionMap.put("xltx", "application/vnd.openxmlformats-officedocument.spreadsheetml.template");
        fileExtensionMap.put("xlsm", "application/vnd.ms-excel.sheet.macroEnabled.12");
        fileExtensionMap.put("xltm", "application/vnd.ms-excel.template.macroEnabled.12");
        fileExtensionMap.put("xlam", "application/vnd.ms-excel.addin.macroEnabled.12");
        fileExtensionMap.put("xlsb", "application/vnd.ms-excel.sheet.binary.macroEnabled.12");
        fileExtensionMap.put("ppt", "application/vnd.ms-powerpoint");
        fileExtensionMap.put("pot", "application/vnd.ms-powerpoint");
        fileExtensionMap.put("pps", "application/vnd.ms-powerpoint");
        fileExtensionMap.put("ppa", "application/vnd.ms-powerpoint");
        fileExtensionMap.put("pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation");
        fileExtensionMap.put("potx", "application/vnd.openxmlformats-officedocument.presentationml.template");
        fileExtensionMap.put("ppsx", "application/vnd.openxmlformats-officedocument.presentationml.slideshow");
        fileExtensionMap.put("ppam", "application/vnd.ms-powerpoint.addin.macroEnabled.12");
        fileExtensionMap.put("pptm", "application/vnd.ms-powerpoint.presentation.macroEnabled.12");
        fileExtensionMap.put("potm", "application/vnd.ms-powerpoint.presentation.macroEnabled.12");
        fileExtensionMap.put("ppsm", "application/vnd.ms-powerpoint.slideshow.macroEnabled.12");
        // Open Office
        fileExtensionMap.put("odt", "application/vnd.oasis.opendocument.text");
        fileExtensionMap.put("ott", "application/vnd.oasis.opendocument.text-template");
        fileExtensionMap.put("oth", "application/vnd.oasis.opendocument.text-web");
        fileExtensionMap.put("odm", "application/vnd.oasis.opendocument.text-master");
        fileExtensionMap.put("odg", "application/vnd.oasis.opendocument.graphics");
        fileExtensionMap.put("otg", "application/vnd.oasis.opendocument.graphics-template");
        fileExtensionMap.put("odp", "application/vnd.oasis.opendocument.presentation");
        fileExtensionMap.put("otp", "application/vnd.oasis.opendocument.presentation-template");
        fileExtensionMap.put("ods", "application/vnd.oasis.opendocument.spreadsheet");
        fileExtensionMap.put("ots", "application/vnd.oasis.opendocument.spreadsheet-template");
        fileExtensionMap.put("odc", "application/vnd.oasis.opendocument.chart");
        fileExtensionMap.put("odf", "application/vnd.oasis.opendocument.formula");
        fileExtensionMap.put("odb", "application/vnd.oasis.opendocument.database");
        fileExtensionMap.put("odi", "application/vnd.oasis.opendocument.image");
        fileExtensionMap.put("oxt", "application/vnd.openofficeorg.extension");
    }

    public static String getContentTypeByFileName(String fileName) {
        // 1. first use java's buildin utils
        FileNameMap mimeTypes = URLConnection.getFileNameMap();
        String contentType = mimeTypes.getContentTypeFor(fileName);
        // 2. nothing found -> lookup our in extension map to find types like ".doc" or ".docx"
        if (!StringUtils.hasText(contentType)) {
            String extension = FilenameUtils.getExtension(fileName);
            contentType = fileExtensionMap.get(extension);
        }
        return contentType;
    }
}

Answer 2

使用Apache tika进行内容检测。 请在下面找到链接。 http://tika.apache.org/0.8/detection.html 。 我们有很多jar依赖项，当您使用Maven构建Tika时可以找到

        ByteArrayInputStream bai = new ByteArrayInputStream(pByte);
        ContentHandler contenthandler = new BodyContentHandler();
        Metadata metadata = new Metadata();
        Parser parser = new AutoDetectParser();
        try {
              parser.parse(bai, contenthandler, metadata);

        } catch (IOException e) {
              // TODO Auto-generated catch block
              e.printStackTrace();
        } catch (SAXException e) {
              // TODO Auto-generated catch block
              e.printStackTrace();
        } catch (TikaException e) {
              // TODO Auto-generated catch block
              e.printStackTrace();
        }           
        System.out.println("Mime: " + metadata.get(Metadata.CONTENT_TYPE));
        return metadata.get(Metadata.CONTENT_TYPE);

Answer 3

我使用javax.activation.MimetypesFileTypeMap 。 它以一小集开始： $JRE_HOME/lib/content-types.properties ，但是您可以添加自己的。 以MimetypesFileTypeMap的javadoc中显示的格式创建文件mime.types （我从网络上的一个大列表开始，对其进行了按摩，并添加了发现的丢失的类型）。 现在，您可以通过打开mime.types文件并将其内容添加到地图中，在代码中添加它。 但是，更简单的解决方案是将mime.types文件添加到jar的META-INF中。 java.activation将自动进行处理。