SlingTikaDetector.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with this
 * work for additional information regarding copyright ownership. The ASF
 * licenses this file to You under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package org.apache.sling.jcr.webdav.impl.helper;

import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import org.apache.sling.commons.mime.MimeTypeService;
import org.apache.tika.detect.Detector;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.mime.MediaType;

public class SlingTikaDetector implements Detector {

    private final MimeTypeService mimeTypeService;

    public SlingTikaDetector(MimeTypeService mimeTypeService) {
        this.mimeTypeService = mimeTypeService;
    }

    public MediaType detect(InputStream rawData, Metadata metadata) {

        // NOTE: This implementation is built after the Tika NameDetector
        //    implementation which only takes the resource name into
        //    consideration when trying to detect the MIME type.

        // Look for a resource name in the input metadata
        String name = metadata.get(Metadata.RESOURCE_NAME_KEY);
        if (name != null) {
            // If the name is a URL, skip the trailing query and fragment parts
            int question = name.indexOf('?');
            if (question != -1) {
                name = name.substring(0, question);
            }
            int hash = name.indexOf('#');
            if (hash != -1) {
                name = name.substring(0, hash);
            }

            // If the name is a URL or a path, skip all but the last component
            int slash = name.lastIndexOf('/');
            if (slash != -1) {
                name = name.substring(slash + 1);
            }
            int backslash = name.lastIndexOf('\\');
            if (backslash != -1) {
                name = name.substring(backslash + 1);
            }

            // Decode any potential URL encoding
            int percent = name.indexOf('%');
            if (percent != -1) {
                try {
                    name = URLDecoder.decode(name, "UTF-8");
                } catch (UnsupportedEncodingException e) {
                    throw new AssertionError("UTF-8 not supported");
                }
            }

            // Skip any leading or trailing whitespace
            name = name.trim();
            if (name.length() > 0) {
                // Match the name against the registered patterns
                String type = mimeTypeService.getMimeType(name);
                if (type != null) {
                    return MediaType.parse(type);
                }
            }
        }

        return MediaType.OCTET_STREAM;
    }

}