轉載於:http://www.rgagnon.com/javadetails/java-0487.html php
中文翻譯:http://chinacheng.iteye.com/blog/857485 html
import java.io.IOException; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; public class Test { public static void main(String[] args) throws IOException { Path source = Paths.get("c:/temp/0multipage.tif"); System.out.println(Files.probeContentType(source)); // output : image/tiff } }
The MimetypesFileMap class is used to map a File to a Mime Type. Mime types supported are defined in a ressource file inside the activation.jar. java
import javax.activation.MimetypesFileTypeMap; import java.io.File; class GetMimeType { public static void main(String args[]) { File f = new File("gumby.gif"); System.out.println("Mime Type of " + f.getName() + " is " + new MimetypesFileTypeMap().getContentType(f)); // expected output : // "Mime Type of gumby.gif is image/gif" } }
The MimetypesFileTypeMap looks in various places in the user's system for MIME types file entries. When requests are made to search for MIME types in the MimetypesFileTypeMap, it searches MIME types files in the following order: git
Like the above method a match is done with the extension. The mapping between the extension and the mime-type is defined in the file [jre_home]\lib\content-types.properties web
import java.net.*; public class FileUtils{ public static String getMimeType(String fileUrl) throws java.io.IOException, MalformedURLException { String type = null; URL u = new URL(fileUrl); URLConnection uc = null; uc = u.openConnection(); type = uc.getContentType(); return type; } public static void main(String args[]) throws Exception { System.out.println(FileUtils.getMimeType("file://c:/temp/test.TXT")); // output : text/plain } }
I was trying to find the best way of getting the mime type of a file and found your sight very useful. However I have now found a way of getting the mime type using URLConnection that isn't as slow as the way you describe.
import java.net.FileNameMap; import java.net.URLConnection; public class FileUtils { public static String getMimeType(String fileUrl) throws java.io.IOException { FileNameMap fileNameMap = URLConnection.getFileNameMap(); String type = fileNameMap.getContentTypeFor(fileUrl); return type; } public static void main(String args[]) throws Exception { System.out.println(FileUtils.getMimeType("file://c:/temp/test.TXT")); // output : text/plain } }
This package is very up-to-date regarding the filetypes supported, Office 2007 formats are supported (docs/pptx/xlsx/etc...). apache
Apache Tika api
Tika has a lot of dependencies ... almost 20 jars ! But it can do a lot more than detecting filetype. For example, you can parse a PDF or DOC to extract the text and the metadata very easily. oracle
import java.io.File; import java.io.FileInputStream; import org.apache.tika.metadata.Metadata; import org.apache.tika.parser.AutoDetectParser; import org.apache.tika.parser.Parser; import org.apache.tika.sax.BodyContentHandler; import org.xml.sax.ContentHandler; public class Main { public static void main(String args[]) throws Exception { FileInputStream is = null; try { File f = new File("C:/Temp/mime/test.docx"); is = new FileInputStream(f); ContentHandler contenthandler = new BodyContentHandler(); Metadata metadata = new Metadata(); metadata.set(Metadata.RESOURCE_NAME_KEY, f.getName()); Parser parser = new AutoDetectParser(); // OOXMLParser parser = new OOXMLParser(); parser.parse(is, contenthandler, metadata); System.out.println("Mime: " + metadata.get(Metadata.CONTENT_TYPE)); System.out.println("Title: " + metadata.get(Metadata.TITLE)); System.out.println("Author: " + metadata.get(Metadata.AUTHOR)); System.out.println("content: " + contenthandler.toString()); } catch (Exception e) { e.printStackTrace(); } finally { if (is != null) is.close(); } } }
// snippet for JMimeMagic lib // http://sourceforge.net/projects/jmimemagic/ Magic parser = new Magic() ; // getMagicMatch accepts Files or byte[], // which is nice if you want to test streams MagicMatch match = parser.getMagicMatch(new File("gumby.gif")); System.out.println(match.getMimeType()) ;
import eu.medsea.mimeutil.MimeUtil; public class Main { public static void main(String[] args) { MimeUtil.registerMimeDetector("eu.medsea.mimeutil.detector.MagicMimeMimeDetector"); File f = new File ("c:/temp/mime/test.doc"); Collection<?> mimeTypes = MimeUtil.getMimeTypes(f); System.out.println(mimeTypes); // output : application/msword } }
DROID uses internal and external signatures to identify and report the specific file format versions of digital files. These signatures are stored in an XML signature file, generated from information recorded in the PRONOM technical registry. New and updated signatures are regularly added to PRONOM, and DROID can be configured to automatically download updated signature files from the PRONOM website via web services. app
It can be invoked from two interfaces, a Java Swing GUI or a command line interface. ide
http://droid.sourceforge.net/wiki/index.php/Introduction
The Aperture code consists of a number of related but independently usable parts: