com.kolich.common.util.io.GZIPCompressor.java Source code

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Here is the source code for com.kolich.common.util.io.GZIPCompressor.java

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/**
 * Copyright (c) 2015 Mark S. Kolich
 * http://mark.koli.ch
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

package com.kolich.common.util.io;

import static org.apache.commons.io.IOUtils.closeQuietly;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.util.zip.Deflater;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

import org.apache.commons.io.IOUtils;

import com.kolich.common.KolichCommonException;

public final class GZIPCompressor {

    /**
     * The DEFAULT_BUFFER_SIZE in {@link org.apache.commons.io.IOUtils}
     * is 4KB.  Looking at the source of GZIPInputStream and
     * GZIPOutputStream in the JDK, we see that their default buffer
     * sizes are 512-bytes.  When the GZIP stream buffer sizes do not match
     * the size of the copy buffer in {@link org.apache.commons.io.IOUtils},
     * performance takes a hit.  As a result, the default buffer size here is
     * set to match IOUtils at 4KB for best performance.
     */
    private static final int DEFAULT_BUFFER_SIZE = 4096;

    // Cannot be instantiated.
    private GZIPCompressor() {
    }

    /**
     * Given an uncompressed InputStream, compress it and return the
     * result as new byte array.
     * @return
     */
    public static final byte[] compress(final InputStream is, final int outputBufferSize) {
        GZIPOutputStream gzos = null;
        try {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            gzos = new GZIPOutputStream(baos, outputBufferSize) {
                // Ugly anonymous constructor hack to set the compression
                // level on the underlying Deflater to "max compression".
                {
                    def.setLevel(Deflater.BEST_COMPRESSION);
                }
            };
            IOUtils.copyLarge(is, gzos);
            gzos.finish();
            return baos.toByteArray();
        } catch (Exception e) {
            throw new GZIPCompressorException(e);
        } finally {
            closeQuietly(gzos);
        }
    }

    /**
     * Given an uncompressed byte-array, compress it using GZIP
     * compression and return the compressed array.
     * @param input
     * @return
     */
    public static final byte[] compress(final byte[] input, final int size) {
        return compress(new ByteArrayInputStream(input), size);
    }

    /**
     * Given an uncompressed byte-array, compress it using GZIP
     * compression and return the compressed array.  Uses a default
     * GZIP stream buffer size of 4KB.
     * @param input
     * @return
     */
    public static final byte[] compress(final byte[] input) {
        return compress(input, DEFAULT_BUFFER_SIZE);
    }

    /**
     * Given a GZIP'ed compressed InputStream, uncompresses it and returns
     * the result as new byte array.  Does NOT close the InputStream; it's
     * up to the caller to close the InputStream when necessary.
     * @param toUncompress
     * @return
     */
    public static final byte[] uncompress(final InputStream is, final int size) {
        GZIPInputStream gzis = null;
        try {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            gzis = new GZIPInputStream(is, size);
            IOUtils.copyLarge(gzis, baos);
            return baos.toByteArray();
        } catch (Exception e) {
            throw new GZIPCompressorException(e);
        } finally {
            IOUtils.closeQuietly(gzis);
        }
    }

    /**
     * Given a GZIP'ed compressed byte array, uncompresses it and returns
     * the result as new byte array.
     */
    public static final byte[] uncompress(final byte[] input, final int size) {
        return uncompress(new ByteArrayInputStream(input), size);
    }

    /**
     * Given a GZIP'ed compressed by array, uncompresses it and returns
     * the result as a new byte array.  Uses a default GZIP stream buffer
     * size of 4KB.
     * @param input
     * @return
     */
    public static final byte[] uncompress(final byte[] input) {
        return uncompress(input, DEFAULT_BUFFER_SIZE);
    }

    public static final class GZIPCompressorException extends KolichCommonException {

        private static final long serialVersionUID = -3848061272831604919L;

        public GZIPCompressorException(String message, Throwable cause) {
            super(message, cause);
        }

        public GZIPCompressorException(String message) {
            super(message);
        }

        public GZIPCompressorException(Throwable cause) {
            super(cause);
        }

    }

}