net.grinder.util.LogCompressUtils.java Source code

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Here is the source code for net.grinder.util.LogCompressUtils.java

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/* 
 * 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 net.grinder.util;

import org.apache.commons.io.IOUtils;
import org.apache.commons.io.output.ByteArrayOutputStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.*;
import java.nio.charset.Charset;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipOutputStream;

import static org.ngrinder.common.util.Preconditions.checkNotNull;

/**
 * Log compress utility. This class mainly provide the compress a single log file.
 *
 * @author JunHo Yoon
 * @since 3.0
 */
public abstract class LogCompressUtils {
    private static final int COMPRESS_BUFFER_SIZE = 8096;
    public static final Logger LOGGER = LoggerFactory.getLogger(LogCompressUtils.class);

    /**
     * Compress multiple Files with the given encoding.
     *
     * @param logFiles     files to be compressed
     * @param fromEncoding log file encoding
     * @param toEncoding   compressed log file encoding
     * @return compressed file byte array
     */
    public static byte[] compress(File[] logFiles, Charset fromEncoding, Charset toEncoding) {
        FileInputStream fis = null;
        InputStreamReader isr = null;
        ByteArrayOutputStream out = null;
        ZipOutputStream zos = null;
        OutputStreamWriter osw = null;
        if (toEncoding == null) {
            toEncoding = Charset.defaultCharset();
        }
        if (fromEncoding == null) {
            fromEncoding = Charset.defaultCharset();
        }
        try {
            out = new ByteArrayOutputStream();
            zos = new ZipOutputStream(out);
            osw = new OutputStreamWriter(zos, toEncoding);
            for (File each : logFiles) {
                try {
                    fis = new FileInputStream(each);
                    isr = new InputStreamReader(fis, fromEncoding);
                    ZipEntry zipEntry = new ZipEntry(each.getName());
                    zipEntry.setTime(each.lastModified());
                    zos.putNextEntry(zipEntry);
                    char[] buffer = new char[COMPRESS_BUFFER_SIZE];
                    int count;
                    while ((count = isr.read(buffer, 0, COMPRESS_BUFFER_SIZE)) != -1) {
                        osw.write(buffer, 0, count);
                    }
                    osw.flush();
                    zos.flush();
                    zos.closeEntry();
                } catch (IOException e) {
                    LOGGER.error("Error occurs while compressing {} : {}", each.getAbsolutePath(), e.getMessage());
                    LOGGER.debug("Details ", e);
                } finally {
                    IOUtils.closeQuietly(isr);
                    IOUtils.closeQuietly(fis);
                }
            }
            zos.finish();
            zos.flush();
            return out.toByteArray();
        } catch (IOException e) {
            LOGGER.error("Error occurs while compressing log : {} ", e.getMessage());
            LOGGER.debug("Details : ", e);
            return null;
        } finally {
            IOUtils.closeQuietly(zos);
            IOUtils.closeQuietly(out);
            IOUtils.closeQuietly(osw);
        }
    }

    /**
     * Compress the given file with the system encoding.
     *
     * @param logFiles files to be compressed
     * @return compressed file byte array
     */
    public static byte[] compress(File[] logFiles) {
        return compress(logFiles, Charset.defaultCharset(), Charset.defaultCharset());
    }

    /**
     * Compress the given file with the system encoding.
     *
     * @param logFile file to be compressed
     * @return compressed file byte array
     */
    public static byte[] compress(File logFile) {
        return compress(new File[] { logFile }, Charset.defaultCharset(), Charset.defaultCharset());
    }

    /**
     * Extracting the given byte array  into the given file.
     *
     * @param zipEntry byte array of compressed file
     * @param toFile   file to be written
     */
    public static void decompress(byte[] zipEntry, File toFile) {
        FileOutputStream fos = null;
        ByteArrayInputStream bio = new ByteArrayInputStream(zipEntry);
        try {
            fos = new FileOutputStream(toFile);
            decompress(bio, fos, Long.MAX_VALUE);
        } catch (IOException e) {
            LOGGER.error("Error occurs during extracting to {} : {} ", toFile.getAbsolutePath(), e.getMessage());
            LOGGER.debug("Details : ", e);
        } finally {
            IOUtils.closeQuietly(fos);
            IOUtils.closeQuietly(bio);
        }
    }

    /**
     * Decompress the given the {@link InputStream} into the given {@link OutputStream}.
     *
     * @param inputStream  input stream of the compressed file
     * @param outputStream file to be written
     * @param limit        the limit of the output
     */
    public static void decompress(InputStream inputStream, OutputStream outputStream, long limit) {
        ZipInputStream zipInputStream = null;
        try {
            zipInputStream = new ZipInputStream(inputStream);
            byte[] buffer = new byte[COMPRESS_BUFFER_SIZE];
            int count;
            long total = 0;
            checkNotNull(zipInputStream.getNextEntry(), "In zip, it should have at least one entry");
            do {
                while ((count = zipInputStream.read(buffer, 0, COMPRESS_BUFFER_SIZE)) != -1) {
                    total += count;
                    if (total >= limit) {
                        break;
                    }
                    outputStream.write(buffer, 0, count);
                }
            } while (zipInputStream.getNextEntry() != null);
            outputStream.flush();
        } catch (IOException e) {
            LOGGER.error("Error occurs while decompressing {}", e.getMessage());
            LOGGER.debug("Details : ", e);
        } finally {
            IOUtils.closeQuietly(zipInputStream);
        }
    }

}