/tika-parsers/src/main/java/org/apache/tika/detect/ZipContainerDetector.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.tika.detect;

import java.io.IOException;
import java.io.InputStream;
import java.util.Collections;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

import org.apache.poi.extractor.ExtractorFactory;
import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.openxml4j.opc.PackagePart;
import org.apache.poi.openxml4j.opc.PackageRelationshipCollection;
import org.apache.tika.io.IOUtils;
import org.apache.tika.io.TikaInputStream;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.mime.MediaType;


/**
 * A detector that works on a Zip document
 *  to figure out exactly what the file is
 */
public class ZipContainerDetector implements ContainerDetector {
    public MediaType getDefault() {
       return MediaType.APPLICATION_ZIP;
    }

    public MediaType detect(InputStream input, Metadata metadata)
             throws IOException {
        if (TikaInputStream.isTikaInputStream(input)) {
            return detect(TikaInputStream.get(input), metadata);
        } else {
            return MediaType.APPLICATION_ZIP;
        }
    }

    public MediaType detect(TikaInputStream input, Metadata metadata) throws IOException {
       ZipFile zip = new ZipFile(input.getFile());
       for (ZipEntry entry : Collections.list(zip.entries())) {
          // Is it an Open Document file?
          if (entry.getName().equals("mimetype")) {
             InputStream stream = zip.getInputStream(entry);
             try {
                return fromString(IOUtils.toString(stream, "UTF-8"));
             } finally {
                stream.close();
             }
          } else if (entry.getName().equals("_rels/.rels") || 
                entry.getName().equals("[Content_Types].xml")) {
             // Office Open XML File
             // As POI to open and investigate it for us
             try {
                OPCPackage pkg = OPCPackage.open(input.getFile().toString());
                input.setOpenContainer(pkg);

                PackageRelationshipCollection core = 
                   pkg.getRelationshipsByType(ExtractorFactory.CORE_DOCUMENT_REL);
                if(core.size() != 1) {
                   throw new IOException("Invalid OOXML Package received - expected 1 core document, found " + core.size());
                }

                // Get the type of the core document part
                PackagePart corePart = pkg.getPart(core.getRelationship(0));
                String coreType = corePart.getContentType();

                // Turn that into the type of the overall document
                String docType = coreType.substring(0, coreType.lastIndexOf('.'));
                return fromString(docType);
             } catch(InvalidFormatException e) {
                throw new IOException("Office Open XML File detected, but corrupted - " + e.getMessage());
             }
          } else if(entry.getName().equals("buildVersionHistory.plist")) {
             // TODO - iWork
          } else if(entry.getName().equals("META-INF/")) {
             // Java Jar
             return MediaType.application("java-archive");
          }
       }

       return MediaType.APPLICATION_ZIP;
    }
    
    private static MediaType fromString(String type) {
        int splitAt = type.indexOf('/');
        if(splitAt > -1) {
            return new MediaType(
        	    type.substring(0,splitAt), 
        	    type.substring(splitAt+1)
            );
        }
        return MediaType.APPLICATION_ZIP;
    }
}