| package org.apache.helix.util; |
| |
| /* |
| * 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.ByteArrayInputStream; |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import java.util.zip.GZIPInputStream; |
| import java.util.zip.GZIPOutputStream; |
| |
| public class GZipCompressionUtil { |
| /** |
| * Compresses a byte array by applying GZIP compression |
| * @param serializedBytes |
| * @return |
| * @throws IOException |
| */ |
| public static byte[] compress(byte[] buffer) throws IOException { |
| ByteArrayOutputStream gzipByteArrayOutputStream = new ByteArrayOutputStream(); |
| GZIPOutputStream gzipOutputStream = null; |
| gzipOutputStream = new GZIPOutputStream(gzipByteArrayOutputStream); |
| gzipOutputStream.write(buffer, 0, buffer.length); |
| gzipOutputStream.close(); |
| byte[] compressedBytes = gzipByteArrayOutputStream.toByteArray(); |
| return compressedBytes; |
| } |
| |
| public static byte[] uncompress(ByteArrayInputStream bais) throws IOException { |
| GZIPInputStream gzipInputStream = new GZIPInputStream(bais); |
| byte[] buffer = new byte[1024]; |
| int length; |
| ByteArrayOutputStream baos = new ByteArrayOutputStream(); |
| while ((length = gzipInputStream.read(buffer)) != -1) { |
| baos.write(buffer, 0, length); |
| } |
| gzipInputStream.close(); |
| baos.close(); |
| byte[] uncompressedBytes = baos.toByteArray(); |
| return uncompressedBytes; |
| } |
| |
| /* |
| * Determines if a byte array is compressed. The java.util.zip GZip |
| * implementaiton does not expose the GZip header so it is difficult to determine |
| * if a string is compressed. |
| * @param bytes an array of bytes |
| * @return true if the array is compressed or false otherwise |
| */ |
| public static boolean isCompressed(byte[] bytes) { |
| if ((bytes == null) || (bytes.length < 2)) { |
| return false; |
| } else { |
| return ((bytes[0] == (byte) (GZIPInputStream.GZIP_MAGIC)) && (bytes[1] == (byte) (GZIPInputStream.GZIP_MAGIC >> 8))); |
| } |
| } |
| } |