Java tutorial
package org.apache.tika.batch.fs; /* * 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. */ import java.io.BufferedOutputStream; import java.io.File; import java.io.IOException; import java.io.OutputStream; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; import java.util.zip.GZIPOutputStream; import org.apache.commons.compress.archivers.zip.ZipArchiveOutputStream; import org.apache.commons.compress.compressors.bzip2.BZip2CompressorOutputStream; import org.apache.tika.batch.OutputStreamFactory; import org.apache.tika.metadata.Metadata; public class FSOutputStreamFactory implements OutputStreamFactory { public enum COMPRESSION { NONE, BZIP2, GZIP, ZIP } private final FSUtil.HANDLE_EXISTING handleExisting; private final Path outputRoot; private final String suffix; private final COMPRESSION compression; /** * * @param outputRoot * @param handleExisting * @param compression * @param suffix * @see #FSOutputStreamFactory(Path, FSUtil.HANDLE_EXISTING, COMPRESSION, String) */ @Deprecated public FSOutputStreamFactory(File outputRoot, FSUtil.HANDLE_EXISTING handleExisting, COMPRESSION compression, String suffix) { this(Paths.get(outputRoot.toURI()), handleExisting, compression, suffix); } public FSOutputStreamFactory(Path outputRoot, FSUtil.HANDLE_EXISTING handleExisting, COMPRESSION compression, String suffix) { this.handleExisting = handleExisting; this.outputRoot = outputRoot; this.suffix = suffix; this.compression = compression; } /** * This tries to create a file based on the {@link org.apache.tika.batch.fs.FSUtil.HANDLE_EXISTING} * value that was passed in during initialization. * <p> * If {@link #handleExisting} is set to "SKIP" and the output file already exists, * this will return null. * <p> * If an output file can be found, this will try to mkdirs for that output file. * If mkdirs() fails, this will throw an IOException. * <p> * Finally, this will open an output stream for the appropriate output file. * @param metadata must have a value set for FSMetadataProperties.FS_ABSOLUTE_PATH or * else NullPointerException will be thrown! * @return OutputStream * @throws java.io.IOException, NullPointerException */ @Override public OutputStream getOutputStream(Metadata metadata) throws IOException { String initialRelativePath = metadata.get(FSProperties.FS_REL_PATH); Path outputPath = FSUtil.getOutputPath(outputRoot, initialRelativePath, handleExisting, suffix); if (outputPath == null) { return null; } if (!Files.isDirectory(outputPath.getParent())) { Files.createDirectories(outputPath.getParent()); //TODO: shouldn't need this any more in java 7, right? if (!Files.isDirectory(outputPath.getParent())) { throw new IOException("Couldn't create parent directory for:" + outputPath.toAbsolutePath()); } } OutputStream os = Files.newOutputStream(outputPath); switch (compression) { case BZIP2: os = new BZip2CompressorOutputStream(os); break; case GZIP: os = new GZIPOutputStream(os); break; case ZIP: os = new ZipArchiveOutputStream(os); break; } return new BufferedOutputStream(os); } }