com.hurence.logisland.util.GZipUtil Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of logisland-utils Show documentation
There is a newer version: 1.4.1
/**
 * Copyright (C) 2016 Hurence ([email protected])
 *
 * Licensed 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 com.hurence.logisland.util;

/*******************************************************************************
 * Copyright (C) 2015 - Amit Kumar Mondal 
 *
 * Licensed 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.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

public class GZipUtil {

    public static boolean isCompressed(byte[] bytes) throws IOException {
        if ((bytes == null) || (bytes.length < 2)) {
            return false;
        } else {
            return ((bytes[0] == (byte) (GZIPInputStream.GZIP_MAGIC)) && (bytes[1] == (byte) (GZIPInputStream.GZIP_MAGIC >> 8)));
        }
    }

    public static byte[] compress(byte[] source) throws IOException {

        final ByteArrayOutputStream baos = new ByteArrayOutputStream();
        GZIPOutputStream gzipos = null;
        try {
            gzipos = new GZIPOutputStream(baos);
            gzipos.write(source);
        } catch (final IOException e) {
            throw e;
        } finally {
            if (gzipos != null) {
                try {
                    gzipos.close();
                } catch (final IOException e) {
                    // Ignore
                }
            }
        }
        return baos.toByteArray();
    }

    public static byte[] decompress(byte[] source) throws IOException {
        final ByteArrayOutputStream baos = new ByteArrayOutputStream();
        final ByteArrayInputStream bais = new ByteArrayInputStream(source);
        GZIPInputStream gzipis = null;

        try {
            gzipis = new GZIPInputStream(bais);

            int n;
            final int MAX_BUF = 1024;
            final byte[] buf = new byte[MAX_BUF];
            while ((n = gzipis.read(buf, 0, MAX_BUF)) != -1) {
                baos.write(buf, 0, n);
            }
        } catch (final IOException e) {
            throw e;
        } finally {
            if (gzipis != null) {
                try {
                    gzipis.close();
                } catch (final IOException e) {
                    // Ignore
                }
            }

            try {
                baos.close();
            } catch (final IOException e) {
                // Ignore
            }
        }

        return baos.toByteArray();
    }
}