com.ctriposs.r2.filter.compression.DeflateCompressor.java Source code

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Here is the source code for com.ctriposs.r2.filter.compression.DeflateCompressor.java

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/**
 * Copyright (C) 2014 the original author or authors.
 * See the notice.md file distributed with this work for additional
 * information regarding copyright ownership.
 *
 * 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.ctriposs.r2.filter.compression;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.DataFormatException;
import java.util.zip.Deflater;
import java.util.zip.Inflater;

import org.apache.commons.io.IOUtils;

/**
 * Wrapper class for zlib compression.
 * */
public class DeflateCompressor implements Compressor {
    private final static String HTTP_NAME = "deflate";

    @Override
    public String getContentEncodingName() {
        return HTTP_NAME;
    }

    @Override
    public byte[] inflate(InputStream data) throws CompressionException {
        byte[] input;
        try {
            input = IOUtils.toByteArray(data);
        } catch (IOException e) {
            throw new CompressionException(CompressionConstants.DECODING_ERROR + CompressionConstants.BAD_STREAM,
                    e);
        }

        Inflater zlib = new Inflater();
        zlib.setInput(input);

        ByteArrayOutputStream output = new ByteArrayOutputStream();
        byte[] temp = new byte[CompressionConstants.BUFFER_SIZE];

        int bytesRead;
        while (!zlib.finished()) {
            try {
                bytesRead = zlib.inflate(temp);
            } catch (DataFormatException e) {
                throw new CompressionException(CompressionConstants.DECODING_ERROR + getContentEncodingName(), e);
            }
            if (bytesRead == 0) {
                if (!zlib.needsInput()) {
                    throw new CompressionException(CompressionConstants.DECODING_ERROR + getContentEncodingName());
                } else {
                    break;
                }
            }

            if (bytesRead > 0) {
                output.write(temp, 0, bytesRead);
            }
        }

        zlib.end();
        return output.toByteArray();
    }

    @Override
    public byte[] deflate(InputStream data) throws CompressionException {
        byte[] input;
        try {
            input = IOUtils.toByteArray(data);
        } catch (IOException e) {
            throw new CompressionException(CompressionConstants.DECODING_ERROR + CompressionConstants.BAD_STREAM,
                    e);
        }

        Deflater zlib = new Deflater();
        zlib.setInput(input);
        zlib.finish();

        ByteArrayOutputStream output = new ByteArrayOutputStream();
        byte[] temp = new byte[CompressionConstants.BUFFER_SIZE];

        int bytesRead;
        while (!zlib.finished()) {
            bytesRead = zlib.deflate(temp);

            if (bytesRead == 0) {
                if (!zlib.needsInput()) {
                    throw new CompressionException(CompressionConstants.DECODING_ERROR + getContentEncodingName());
                } else {
                    break;
                }
            }
            output.write(temp, 0, bytesRead);
        }
        zlib.end();

        return output.toByteArray();
    }
}