Closes #639: rework mime type resolution using java api

docs-core/src/main/java/com/sismics/util/mime/MimeTypeUtil.java

@@ -1,16 +1,9 @@
 package com.sismics.util.mime;
 
-import com.google.common.base.Charsets;
-import org.apache.commons.compress.utils.IOUtils;
-
 import java.io.IOException;
-import java.io.InputStream;
 import java.net.URLConnection;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.util.zip.ZipEntry;
-import java.util.zip.ZipInputStream;
 
 /**
  * Utility to check MIME types.
@@ -19,7 +12,7 @@ import java.util.zip.ZipInputStream;
  */
 public class MimeTypeUtil {
     /**
-     * Try to guess the MIME type of a file by its magic number (header).
+     * Try to guess the MIME type of a file.
      * 
      * @param file File to inspect
      * @param name File name
@@ -27,59 +20,17 @@ public class MimeTypeUtil {
      * @throws IOException e
      */
     public static String guessMimeType(Path file, String name) throws IOException {
-        String mimeType = name == null ?
-                null : URLConnection.getFileNameMap().getContentTypeFor(name);
+        String mimeType = Files.probeContentType(file);
+
+        if (mimeType == null && name != null) {
+            mimeType = URLConnection.getFileNameMap().getContentTypeFor(name);
+        }
+
         if (mimeType == null) {
-            try (InputStream is = Files.newInputStream(file)) {
-                final byte[] headerBytes = new byte[64];
-                is.read(headerBytes);
-                mimeType = guessMimeType(headerBytes, name);
-            }
+            return MimeType.DEFAULT;
         }
 
-        return guessOpenDocumentFormat(mimeType, file);
-    }
-
-    /**
-     * Try to guess the MIME type of a file by its magic number (header).
-     * 
-     * @param headerBytes File header (first bytes)
-     * @param name File name
-     * @return MIME type
-     */
-    public static String guessMimeType(byte[] headerBytes, String name) {
-        String header = new String(headerBytes, StandardCharsets.US_ASCII);
-
-        // Detect by header bytes
-        if (header.startsWith("PK")) {
-            return MimeType.APPLICATION_ZIP;
-        } else if (header.startsWith("GIF87a") || header.startsWith("GIF89a")) {
-            return MimeType.IMAGE_GIF;
-        } else if (headerBytes[0] == ((byte) 0xff) && headerBytes[1] == ((byte) 0xd8)) {
-            return MimeType.IMAGE_JPEG;
-        } else if (headerBytes[0] == ((byte) 0x89) && headerBytes[1] == ((byte) 0x50) && headerBytes[2] == ((byte) 0x4e) && headerBytes[3] == ((byte) 0x47) &&
-                headerBytes[4] == ((byte) 0x0d) && headerBytes[5] == ((byte) 0x0a) && headerBytes[6] == ((byte) 0x1a) && headerBytes[7] == ((byte) 0x0a)) {
-            return MimeType.IMAGE_PNG;
-        } else if (headerBytes[0] == ((byte) 0x25) && headerBytes[1] == ((byte) 0x50) && headerBytes[2] == ((byte) 0x44) && headerBytes[3] == ((byte) 0x46)) {
-            return MimeType.APPLICATION_PDF;
-        } else if (headerBytes[0] == ((byte) 0x00) && headerBytes[1] == ((byte) 0x00) && headerBytes[2] == ((byte) 0x00)
-                && (headerBytes[3] == ((byte) 0x14) || headerBytes[3] == ((byte) 0x18) || headerBytes[3] == ((byte) 0x20))
-                && headerBytes[4] == ((byte) 0x66) && headerBytes[5] == ((byte) 0x74) && headerBytes[6] == ((byte) 0x79) && headerBytes[7] == ((byte) 0x70)) {
-            return MimeType.VIDEO_MP4;
-        } else if (headerBytes[0] == ((byte) 0x1a) && headerBytes[1] == ((byte) 0x45) && headerBytes[2] == ((byte) 0xdf) && headerBytes[3] == ((byte) 0xa3)) {
-            return MimeType.VIDEO_WEBM;
-        }
-
-        // Detect by file extension
-        if (name != null) {
-            if (name.endsWith(".txt")) {
-                return MimeType.TEXT_PLAIN;
-            } else if (name.endsWith(".csv")) {
-                return MimeType.TEXT_CSV;
-            }
-        }
-
-        return MimeType.DEFAULT;
+        return mimeType;
     }
     
     /**
@@ -116,52 +67,4 @@ public class MimeTypeUtil {
                 return "bin";
         }
     }
-    
-    /**
-     * Guess the MIME type of open document formats (docx and odt).
-     * It's more costly than the simple header check, but needed because open document formats
-     * are simple ZIP files on the outside and much bigger on the inside.
-     * 
-     * @param mimeType Currently detected MIME type
-     * @param file File on disk
-     * @return MIME type
-     */
-    private static String guessOpenDocumentFormat(String mimeType, Path file) {
-        if (!MimeType.APPLICATION_ZIP.equals(mimeType)) {
-            // open document formats are ZIP files
-            return mimeType;
-        }
-        
-        try (InputStream inputStream = Files.newInputStream(file);
-             ZipInputStream zipInputStream = new ZipInputStream(inputStream, Charsets.ISO_8859_1)) {
-            ZipEntry archiveEntry = zipInputStream.getNextEntry();
-            while (archiveEntry != null) {
-                if (archiveEntry.getName().equals("mimetype")) {
-                    // Maybe it's an ODT file
-                    String content = new String(IOUtils.toByteArray(zipInputStream), Charsets.ISO_8859_1);
-                    if (MimeType.OPEN_DOCUMENT_TEXT.equals(content.trim())) {
-                        mimeType = MimeType.OPEN_DOCUMENT_TEXT;
-                        break;
-                    }
-                } else if (archiveEntry.getName().equals("[Content_Types].xml")) {
-                    // Maybe it's a DOCX file
-                    String content = new String(IOUtils.toByteArray(zipInputStream), Charsets.ISO_8859_1);
-                    if (content.contains(MimeType.OFFICE_DOCUMENT)) {
-                        mimeType =  MimeType.OFFICE_DOCUMENT;
-                        break;
-                    } else if (content.contains(MimeType.OFFICE_PRESENTATION)) {
-                        mimeType = MimeType.OFFICE_PRESENTATION;
-                        break;
-                    }
-                }
-    
-                archiveEntry = zipInputStream.getNextEntry();
-            }
-        } catch (Exception e) {
-            // In case of any error, just give up and keep the ZIP MIME type
-            return mimeType;
-        }
-        
-        return mimeType;
-    }
 }

docs-core/src/test/java/com/sismics/util/TestMimeTypeUtil.java

@@ -15,7 +15,7 @@ import java.nio.file.Paths;
  */
 public class TestMimeTypeUtil {
     @Test
-    public void guessOpenDocumentFormatTest() throws Exception {
+    public void test() throws Exception {
         // Detect ODT files
         Path path = Paths.get(ClassLoader.getSystemResource("file/document.odt").toURI());
         Assert.assertEquals(MimeType.OPEN_DOCUMENT_TEXT, MimeTypeUtil.guessMimeType(path, "document.odt"));
@@ -28,7 +28,44 @@ public class TestMimeTypeUtil {
         path = Paths.get(ClassLoader.getSystemResource("file/apache.pptx").toURI());
         Assert.assertEquals(MimeType.OFFICE_PRESENTATION, MimeTypeUtil.guessMimeType(path, "apache.pptx"));
 
+        // Detect XLSX files
+        path = Paths.get(ClassLoader.getSystemResource("file/document.xlsx").toURI());
+        Assert.assertEquals(MimeType.OFFICE_SHEET, MimeTypeUtil.guessMimeType(path, "document.xlsx"));
+
         // Detect TXT files
-        Assert.assertEquals(MimeType.TEXT_PLAIN, MimeTypeUtil.guessMimeType(path, "file.txt"));
+        path = Paths.get(ClassLoader.getSystemResource("file/document.txt").toURI());
+        Assert.assertEquals(MimeType.TEXT_PLAIN, MimeTypeUtil.guessMimeType(path, "document.txt"));
+
+        // Detect CSV files
+        path = Paths.get(ClassLoader.getSystemResource("file/document.csv").toURI());
+        Assert.assertEquals(MimeType.TEXT_CSV, MimeTypeUtil.guessMimeType(path, "document.csv"));
+
+        // Detect PDF files
+        path = Paths.get(ClassLoader.getSystemResource("file/udhr.pdf").toURI());
+        Assert.assertEquals(MimeType.APPLICATION_PDF, MimeTypeUtil.guessMimeType(path, "udhr.pdf"));
+
+        // Detect JPEG files
+        path = Paths.get(ClassLoader.getSystemResource("file/apollo_portrait.jpg").toURI());
+        Assert.assertEquals(MimeType.IMAGE_JPEG, MimeTypeUtil.guessMimeType(path, "apollo_portrait.jpg"));
+
+        // Detect GIF files
+        path = Paths.get(ClassLoader.getSystemResource("file/image.gif").toURI());
+        Assert.assertEquals(MimeType.IMAGE_GIF, MimeTypeUtil.guessMimeType(path, "image.gif"));
+
+        // Detect PNG files
+        path = Paths.get(ClassLoader.getSystemResource("file/image.png").toURI());
+        Assert.assertEquals(MimeType.IMAGE_PNG, MimeTypeUtil.guessMimeType(path, "image.png"));
+
+        // Detect ZIP files
+        path = Paths.get(ClassLoader.getSystemResource("file/document.zip").toURI());
+        Assert.assertEquals(MimeType.APPLICATION_ZIP, MimeTypeUtil.guessMimeType(path, "document.zip"));
+
+        // Detect WEBM files
+        path = Paths.get(ClassLoader.getSystemResource("file/video.webm").toURI());
+        Assert.assertEquals(MimeType.VIDEO_WEBM, MimeTypeUtil.guessMimeType(path, "video.webm"));
+
+        // Detect MP4 files
+        path = Paths.get(ClassLoader.getSystemResource("file/video.mp4").toURI());
+        Assert.assertEquals(MimeType.VIDEO_MP4, MimeTypeUtil.guessMimeType(path, "video.mp4"));
     }
 }

docs-core/src/test/resources/file/document.csv

@@ -0,0 +1,2 @@
+col1,col2
+test,me

docs-core/src/test/resources/file/document.txt

@@ -0,0 +1 @@
+test me.