org.joyqueue.toolkit.io.Compressors Maven / Gradle / Ivy

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/**
 * Copyright 2019 The JoyQueue Authors.
 *
 * 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 org.joyqueue.toolkit.io;

import com.google.common.base.Charsets;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.nio.charset.Charset;

/**
 * 压缩工具类
 * Created by hexiaofeng on 16-5-6.
 */
public abstract class Compressors {

    /**
     * 压缩
     *
     * @param src        字符串
     * @param compressor 压缩器
     * @throws java.io.IOException
     */
    public static byte[] compress(final String src, final Compressor compressor) throws IOException {
        return compress(src, Charsets.UTF_8, compressor);
    }

    /**
     * 压缩
     *
     * @param src        字符串
     * @param charset    字符串
     * @param compressor 压缩器
     * @throws java.io.IOException
     */
    public static byte[] compress(final String src, final Charset charset, final Compressor compressor) throws
            IOException {
        if (src == null) {
            return null;
        }
        if (charset == null) {
            return compress(src.getBytes(), compressor);
        }
        return compress(src.getBytes(charset), compressor);
    }

    /**
     * 压缩
     *
     * @param buf        缓冲器
     * @param compressor 压缩器
     * @return 压缩后的数据
     * @throws IOException
     */
    public static byte[] compress(final byte[] buf, final Compressor compressor) throws IOException {
        if (buf == null) {
            return null;
        }
        return compress(buf, 0, buf.length, compressor);
    }

    /**
     * 压缩
     *
     * @param buf        缓冲器
     * @param offset     偏移量
     * @param size       长度
     * @param compressor 压缩器
     * @return 压缩后的数据
     * @throws IOException
     */
    public static byte[] compress(final byte[] buf, final int offset, final int size,
            final Compressor compressor) throws IOException {
        if (buf == null) {
            return null;
        }
        ByteArrayOutputStream bos = new ByteArrayOutputStream(size);
        try {
            compressor.compress(buf, offset, size, bos);
            return bos.toByteArray();
        } finally {
            bos.close();
        }
    }

    /**
     * 解压缩
     *
     * @param buf        缓冲器
     * @param compressor 压缩器
     * @throws java.io.IOException
     */
    public static byte[] decompress(final byte[] buf, final Compressor compressor) throws IOException {
        if (buf == null) {
            return null;
        }
        return decompress(buf, 0, buf.length, compressor);
    }

    /**
     * 解压缩
     *
     * @param buf        缓冲器
     * @param offset     偏移量
     * @param size       长度
     * @param compressor 压缩器
     * @throws java.io.IOException
     */
    public static byte[] decompress(final byte[] buf, final int offset, final int size,
            final Compressor compressor) throws IOException {
        if (buf == null || buf.length == 0 || size <= 0 || offset >= buf.length) {
            return null;
        }
        ByteArrayOutputStream bos = new ByteArrayOutputStream(size * 4);
        try {
            compressor.decompress(buf, offset, size, bos);
            return bos.toByteArray();
        } finally {
            bos.close();
        }
    }

    /**
     * 解压缩
     *
     * @param buf        缓冲器
     * @param charset    字符集
     * @param compressor 压缩器
     * @throws java.io.IOException
     */
    public static String decompress(final byte[] buf, final Charset charset, final Compressor compressor) throws
            IOException {
        if (buf == null || buf.length == 0) {
            return null;
        }
        return decompress(buf, 0, buf.length, charset, compressor);
    }

    /**
     * 解压缩
     *
     * @param buf        缓冲器
     * @param offset     偏移量
     * @param size       长度
     * @param charset    字符集
     * @param compressor 压缩器
     * @throws java.io.IOException
     */
    public static String decompress(final byte[] buf, final int offset, final int size, final Charset charset,
            final Compressor compressor) throws IOException {
        if (buf == null || buf.length == 0 || size <= 0 || offset >= buf.length) {
            return null;
        }
        ByteArrayOutputStream bos = new ByteArrayOutputStream(size * 4);
        try {
            compressor.decompress(buf, offset, size, bos);
            return bos.toString(charset.toString());
        } finally {
            bos.close();
        }
    }
}