ObjectUtils.java

/*
 * 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.
 */
package hivemall.utils.lang;

import hivemall.utils.io.Base91InputStream;
import hivemall.utils.io.Base91OutputStream;
import hivemall.utils.io.CompressionStreamFactory;
import hivemall.utils.io.CompressionStreamFactory.CompressionAlgorithm;
import hivemall.utils.io.FastByteArrayInputStream;
import hivemall.utils.io.FastByteArrayOutputStream;
import hivemall.utils.io.FastMultiByteArrayOutputStream;
import hivemall.utils.io.FinishableOutputStream;
import hivemall.utils.io.IOUtils;

import java.io.Externalizable;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.util.zip.DeflaterOutputStream;
import java.util.zip.InflaterInputStream;

import javax.annotation.Nonnull;

public final class ObjectUtils {

    private ObjectUtils() {}

    public static byte[] toBytes(@Nonnull final Object obj) throws IOException {
        FastByteArrayOutputStream bos = new FastByteArrayOutputStream();
        toStream(obj, bos);
        return bos.toByteArray();
    }

    public static byte[] toBytes(@Nonnull final Externalizable obj) throws IOException {
        FastByteArrayOutputStream bos = new FastByteArrayOutputStream();
        toStream(obj, bos);
        return bos.toByteArray();
    }

    public static byte[] toCompressedBytes(@Nonnull final Object obj) throws IOException {
        FastMultiByteArrayOutputStream bos = new FastMultiByteArrayOutputStream();
        DeflaterOutputStream dos = new DeflaterOutputStream(bos);
        try {
            toStream(obj, dos);
            dos.finish();
            dos.flush();
            return bos.toByteArray_clear();
        } finally {
            IOUtils.closeQuietly(dos);
        }
    }

    public static byte[] toCompressedBytes(@Nonnull final Externalizable obj) throws IOException {
        FastMultiByteArrayOutputStream bos = new FastMultiByteArrayOutputStream();
        DeflaterOutputStream dos = new DeflaterOutputStream(bos);
        try {
            toStream(obj, dos);
            dos.finish();
            dos.flush();
            return bos.toByteArray_clear();
        } finally {
            IOUtils.closeQuietly(dos);
        }
    }

    public static byte[] toCompressedBytes(@Nonnull final Externalizable obj,
            @Nonnull final CompressionAlgorithm algo, final boolean bin2txt) throws IOException {
        FastMultiByteArrayOutputStream bos = new FastMultiByteArrayOutputStream();
        OutputStream out = null;
        FinishableOutputStream dos = null;
        try {
            out = bin2txt ? new Base91OutputStream(bos) : bos;
            dos = CompressionStreamFactory.createOutputStream(out, algo);
            toStream(obj, dos);
            dos.finish();
            //dos.flush();
            return bos.toByteArray_clear();
        } finally {
            IOUtils.closeQuietly(dos);
            IOUtils.closeQuietly(out);
        }
    }

    public static void toStream(@Nonnull final Object obj, @Nonnull final OutputStream out)
            throws IOException {
        ObjectOutputStream oos = new ObjectOutputStream(out);
        oos.writeObject(obj);
        oos.flush();
    }

    public static void toStream(@Nonnull final Externalizable obj, @Nonnull final OutputStream out)
            throws IOException {
        ObjectOutputStream oos = new ObjectOutputStream(out);
        obj.writeExternal(oos);
        oos.flush();
    }

    public static <T> T readObject(@Nonnull final byte[] obj) throws IOException,
            ClassNotFoundException {
        return readObject(obj, obj.length);
    }

    public static <T> T readObject(@Nonnull final byte[] obj, final int length) throws IOException,
            ClassNotFoundException {
        return readObject(new FastByteArrayInputStream(obj, length));
    }

    public static void readObject(@Nonnull final byte[] src, @Nonnull final Externalizable dst)
            throws IOException, ClassNotFoundException {
        readObject(src, src.length, dst);
    }

    public static void readObject(@Nonnull final byte[] src, final int length,
            @Nonnull final Externalizable dst) throws IOException, ClassNotFoundException {
        readObject(new FastByteArrayInputStream(src, length), dst);
    }

    @SuppressWarnings("unchecked")
    public static <T> T readObject(@Nonnull final InputStream is) throws IOException,
            ClassNotFoundException {
        ObjectInputStream ois = new ObjectInputStream(is);
        return (T) ois.readObject();
    }

    public static void readObject(@Nonnull final InputStream is, @Nonnull final Externalizable dst)
            throws IOException, ClassNotFoundException {
        ObjectInputStream ois = new ObjectInputStream(is);
        dst.readExternal(ois);
    }

    public static <T> T readCompressedObject(@Nonnull final byte[] obj) throws IOException,
            ClassNotFoundException {
        FastByteArrayInputStream bis = new FastByteArrayInputStream(obj);
        final InflaterInputStream iis = new InflaterInputStream(bis);
        try {
            return readObject(iis);
        } finally {
            IOUtils.closeQuietly(iis);
        }
    }

    public static void readCompressedObject(@Nonnull final byte[] src,
            @Nonnull final Externalizable dst) throws IOException, ClassNotFoundException {
        FastByteArrayInputStream bis = new FastByteArrayInputStream(src);
        final InflaterInputStream iis = new InflaterInputStream(bis);
        try {
            readObject(iis, dst);
        } finally {
            IOUtils.closeQuietly(iis);
        }
    }

    public static void readCompressedObject(@Nonnull final byte[] src, final int len,
            @Nonnull final Externalizable dst, @Nonnull final CompressionAlgorithm algo,
            final boolean bin2txt) throws IOException, ClassNotFoundException {
        FastByteArrayInputStream bis = new FastByteArrayInputStream(src, len);
        InputStream in = null;
        InputStream compressedStream = null;
        try {
            in = bin2txt ? new Base91InputStream(bis) : bis;
            compressedStream = CompressionStreamFactory.createInputStream(in, algo);
            readObject(compressedStream, dst);
        } finally {
            IOUtils.closeQuietly(compressedStream);
            IOUtils.closeQuietly(in);
        }
    }

    public static void readCompressedObject(@Nonnull final byte[] src, final int offset,
            final int length, @Nonnull final Externalizable dst) throws IOException,
            ClassNotFoundException {
        FastByteArrayInputStream bis = new FastByteArrayInputStream(src, offset, length);
        final InflaterInputStream iis = new InflaterInputStream(bis);
        try {
            readObject(iis, dst);
        } finally {
            IOUtils.closeQuietly(iis);
        }
    }

    public static <E extends Enum<E>> E fromOrdinal(Class<E> enumClass, int ordinal) {
        E[] enumArray = enumClass.getEnumConstants();
        return enumArray[ordinal];
    }

}