Java tutorial
/* * Copyright [2013-2014] PayPal Software Foundation * * 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 ml.shifu.guagua.io; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.DataInputStream; import java.io.DataOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.Arrays; import ml.shifu.guagua.GuaguaRuntimeException; import ml.shifu.guagua.util.ReflectionUtils; import org.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream; import org.apache.commons.compress.compressors.bzip2.BZip2CompressorOutputStream; /** * {@link Bzip2BytableSerializer} is using bzip2 compression algorithm for serialization. * * <p> * Byte array by using {@link Bzip2BytableSerializer} is bzip2 format. * * @see Serializer * @see BytableSerializer */ public class Bzip2BytableSerializer<RESULT extends Bytable> implements Serializer<RESULT> { /** * Serialize from object to bytes. * * @throws NullPointerException * if result is null. * @throws GuaguaRuntimeException * if any io exception. */ @Override public byte[] objectToBytes(RESULT result) { ByteArrayOutputStream out = null; DataOutputStream dataOut = null; try { out = new ByteArrayOutputStream(); OutputStream gzipOutput = new BZip2CompressorOutputStream(out); dataOut = new DataOutputStream(gzipOutput); result.write(dataOut); } catch (IOException e) { throw new GuaguaRuntimeException(e); } finally { if (dataOut != null) { try { dataOut.close(); } catch (IOException e) { throw new GuaguaRuntimeException(e); } } } return out.toByteArray(); } /** * De-serialize from bytes to object. One should provide the class name before de-serializing the object. * * @throws NullPointerException * if className or data is null. * @throws GuaguaRuntimeException * if any io exception or other reflection exception. */ @Override public RESULT bytesToObject(byte[] data, String className) { if (data == null || className == null) { throw new NullPointerException( String.format("data and className should not be null. data:%s, className:%s", Arrays.toString(data), className)); } @SuppressWarnings("unchecked") RESULT result = (RESULT) ReflectionUtils.newInstance(className); DataInputStream dataIn = null; try { InputStream in = new ByteArrayInputStream(data); InputStream gzipInput = new BZip2CompressorInputStream(in); dataIn = new DataInputStream(gzipInput); result.readFields(dataIn); } catch (Exception e) { throw new GuaguaRuntimeException(e); } finally { if (dataIn != null) { try { dataIn.close(); } catch (IOException e) { throw new GuaguaRuntimeException(e); } } } return result; } }