Files
alfresco-community-repo/source/java/org/alfresco/repo/content/metadata/TikaAutoMetadataExtracter.java
2016-07-01 08:34:26 +00:00

139 lines
5.2 KiB
Java

/*
* #%L
* Alfresco Repository
* %%
* Copyright (C) 2005 - 2016 Alfresco Software Limited
* %%
* This file is part of the Alfresco software.
* If the software was purchased under a paid Alfresco license, the terms of
* the paid license agreement will prevail. Otherwise, the software is
* provided under the following open source license terms:
*
* Alfresco is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Alfresco is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
* #L%
*/
package org.alfresco.repo.content.metadata;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Map;
import org.alfresco.repo.content.MimetypeMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.tika.config.TikaConfig;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.metadata.TIFF;
import org.apache.tika.mime.MediaType;
import org.apache.tika.parser.AutoDetectParser;
import org.apache.tika.parser.Parser;
/**
* A Metadata Extractor which makes use of the Apache
* Tika auto-detection to select the best parser
* to extract the metadata from your document.
* This will be used for all files which Tika can
* handle, but where no other more explicit
* extractor is defined.
* <pre>
* <b>author:</b> -- cm:author
* <b>title:</b> -- cm:title
* <b>subject:</b> -- cm:description
* <b>created:</b> -- cm:created
* <b>comments:</b>
* <b>geo:lat:</b> -- cm:latitude
* <b>geo:long:</b> -- cm:longitude
* </pre>
*
* @since 3.4
* @author Nick Burch
*/
public class TikaAutoMetadataExtracter extends TikaPoweredMetadataExtracter
{
protected static Log logger = LogFactory.getLog(TikaAutoMetadataExtracter.class);
private static AutoDetectParser parser;
private static TikaConfig config;
private static String EXIF_IMAGE_HEIGHT_TAG = "Exif Image Height";
private static String EXIF_IMAGE_WIDTH_TAG = "Exif Image Width";
private static String JPEG_IMAGE_HEIGHT_TAG = "Image Height";
private static String JPEG_IMAGE_WIDTH_TAG = "Image Width";
public static ArrayList<String> SUPPORTED_MIMETYPES;
private static ArrayList<String> buildMimeTypes(TikaConfig tikaConfig)
{
config = tikaConfig;
parser = new AutoDetectParser(config);
SUPPORTED_MIMETYPES = new ArrayList<String>();
for(MediaType mt : parser.getParsers().keySet())
{
// Add the canonical mime type
SUPPORTED_MIMETYPES.add( mt.toString() );
// And add any aliases of the mime type too - Alfresco uses some
// non canonical forms of various mimetypes, so we need all of them
for(MediaType alias : config.getMediaTypeRegistry().getAliases(mt))
{
SUPPORTED_MIMETYPES.add( alias.toString() );
}
}
return SUPPORTED_MIMETYPES;
}
public TikaAutoMetadataExtracter(TikaConfig tikaConfig)
{
super( buildMimeTypes(tikaConfig) );
}
/**
* Does auto-detection to select the best Tika
* Parser.
*/
@Override
protected Parser getParser()
{
return parser;
}
/**
* Because some editors use JPEG_IMAGE_HEIGHT_TAG when
* saving JPEG images , a more reliable source for
* image size are the values provided by Tika
* and not the exif/tiff metadata read from the file
* This will override the tiff:Image size
* which gets embedded into the alfresco node properties
* for jpeg files that contain such exif information
*/
@Override
protected Map<String, Serializable> extractSpecific(Metadata metadata,
Map<String, Serializable> properties, Map<String,String> headers)
{
if(MimetypeMap.MIMETYPE_IMAGE_JPEG.equals(metadata.get(Metadata.CONTENT_TYPE)))
{
//check if the image has exif information
if(metadata.get(EXIF_IMAGE_WIDTH_TAG) != null && metadata.get(EXIF_IMAGE_HEIGHT_TAG) != null )
{
//replace the exif size properties that will be embedded in the node with
//the guessed dimensions from Tika
putRawValue(TIFF.IMAGE_LENGTH.getName(), extractSize(metadata.get(JPEG_IMAGE_HEIGHT_TAG)), properties);
putRawValue(TIFF.IMAGE_WIDTH.getName(), extractSize(metadata.get(JPEG_IMAGE_WIDTH_TAG)), properties);
}
}
return properties;
}
}