Example usage for java.util.zip CRC32 CRC32

Introduction

In this page you can find the example usage for java.util.zip CRC32 CRC32.

Prototype

public CRC32()

Source Link

Document

Creates a new CRC32 object.

Usage

From source file:divconq.ctp.stream.UngzipStream.java

public UngzipStream() {
    this.inflater = new Inflater(true);
    this.crc = new CRC32();
}

From source file:org.tangram.components.CodeExporter.java

@LinkAction("/codes.zip")
public TargetDescriptor codes(HttpServletRequest request, HttpServletResponse response) throws IOException {
    if (!request.getRequestURI().endsWith(".zip")) {
        response.sendError(HttpServletResponse.SC_NOT_FOUND);
        return null;
    } // if/* w  w w  . ja  v a2  s  .c om*/
    if (request.getAttribute(Constants.ATTRIBUTE_ADMIN_USER) == null) {
        throw new IOException("User may not execute action");
    } // if

    long now = System.currentTimeMillis();

    response.setContentType("application/x-zip-compressed");

    CRC32 crc = new CRC32();

    ZipOutputStream zos = new ZipOutputStream(response.getOutputStream());
    zos.setComment("Tangram Repository Codes");
    zos.setLevel(9);
    Collection<CodeResource> codes = codeResourceCache.getCodes();
    for (CodeResource code : codes) {
        if (StringUtils.isNotBlank(code.getAnnotation())) {
            String mimeType = CodeHelper.getNormalizedMimeType(code.getMimeType());
            String folder = CodeHelper.getFolder(mimeType);
            String extension = CodeHelper.getExtension(mimeType);
            if (mimeType.startsWith("text/")) {
                byte[] bytes = code.getCodeText().getBytes("UTF-8");
                ZipEntry ze = new ZipEntry(folder + "/" + getFilename(code) + extension);
                ze.setTime(now);
                crc.reset();
                crc.update(bytes);
                ze.setCrc(crc.getValue());
                zos.putNextEntry(ze);
                zos.write(bytes);
                zos.closeEntry();
            } // if
        } // if
    } // for
    zos.finish();
    zos.close();

    return TargetDescriptor.DONE;
}

From source file:org.bdval.util.ShortHash.java

/**
 * Return a short hash (String of 5 chars, A-Z) of the contents of toHash.
 * @param toHash the content to hash/*from  w ww  .j a  v  a 2s .  com*/
 * @return the short hash
 */
public static String shortHash(final String toHash) {
    if (StringUtils.isBlank(toHash)) {
        return null;
    }

    // Get the CRC32 checksum of the string (CRC will clash less often than the Adler checksum for short strings)
    final CRC32 crc32 = new CRC32();
    crc32.update(toHash.getBytes());
    // Map it from a long to an int with mod
    final int checksum = (int) (crc32.getValue() % Integer.MAX_VALUE);

    final StringBuilder output = new StringBuilder();
    for (int i = 0; i < MASKS.length; i++) {
        // Mask the value, shift it to the right, and mod it to the output-able characters
        final int partial = ((checksum & MASKS[i]) >> MASK_SHIFTS[i]) % HASH_CHARS.length;
        final char asChar = HASH_CHARS[partial];
        output.append(asChar);
    }
    LOG.debug(String.format("hash=%s for string=%s", output.toString(), toHash));
    return output.toString();
}

From source file:org.trellisldp.file.FileUtils.java

/**
 * Get a directory for a given resource identifier.
 * @param baseDirectory the base directory
 * @param identifier a resource identifier
 * @return a directory//from w w  w.  j  a  va 2 s  .c o  m
 */
public static File getResourceDirectory(final File baseDirectory, final IRI identifier) {
    requireNonNull(baseDirectory, "The baseDirectory may not be null!");
    requireNonNull(identifier, "The identifier may not be null!");
    final String id = identifier.getIRIString();
    final StringJoiner joiner = new StringJoiner(separator);
    final CRC32 hasher = new CRC32();
    hasher.update(id.getBytes(UTF_8));
    final String intermediate = Long.toHexString(hasher.getValue());

    range(0, intermediate.length() / LENGTH).limit(MAX)
            .forEach(i -> joiner.add(intermediate.substring(i * LENGTH, (i + 1) * LENGTH)));

    joiner.add(md5Hex(id));
    return new File(baseDirectory, joiner.toString());
}

From source file:MainClass.java

public CRC() {
    super("CRC");
    crc = new CRC32();
}

From source file:com.petercho.Encoder.java

public static long checksumCRC32(String text) {
    CRC32 crc = new CRC32();
    try (InputStream is = new ByteArrayInputStream(text.getBytes(DEFAULT_ENCODING))) {
        checksum(is, crc);/*w  ww .j  a  va 2s . c  om*/
    } catch (IOException e) {
        throw new IllegalStateException("Error getting checksum, e:" + e, e);
    }
    return crc.getValue();
}

From source file:com.yifanlu.PSXperiaTool.ZpakCreate.java

public static long getCRC32(File file) throws IOException {
    CheckedInputStream cis = null;
    long fileSize = 0;
    // Computer CRC32 checksum
    cis = new CheckedInputStream(new FileInputStream(file), new CRC32());

    fileSize = file.length();//from w  ww .j a v a2  s. c  om

    byte[] buf = new byte[128];
    while (cis.read(buf) != -1)
        ;

    long checksum = cis.getChecksum().getValue();
    cis.close();
    Logger.verbose("CRC32 of %s is %d", file.getPath(), checksum);
    return checksum;
}

From source file:org.apache.hadoop.hdfs.RaidDFSUtil.java

public static long getCRC(FileSystem fs, Path p) throws IOException {
    CRC32 crc = new CRC32();
    FSDataInputStream stm = fs.open(p);/*from w  ww .  ja va  2s.c o m*/
    int b;
    while ((b = stm.read()) >= 0) {
        crc.update(b);
    }
    stm.close();
    return crc.getValue();
}

From source file:org.ambiance.codec.YEncEncoder.java

public void encode(File input) throws EncoderException {
    try {//w ww .  ja va 2  s  . c o  m
        // Initialize
        BufferedInputStream bis = new BufferedInputStream(new FileInputStream(input));

        YEncHeader header = new YEncHeader();
        header.setName(input.getName());
        header.setLine(lineSize);

        YEncTrailer trailer = new YEncTrailer();

        CRC32 crc32 = new CRC32();

        StringBuffer outputName = new StringBuffer(outputDirName);
        outputName.append(File.separator);
        outputName.append(header.getName());
        outputName.append(extension);

        BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(outputName.toString()));

        // Read and encode
        int c;
        long size = 0;
        while ((c = bis.read()) != -1) {
            crc32.update(c);
            if (size % header.getLine() == 0 && size != 0) {
                bos.write((int) '\r');
                bos.write((int) '\n');
            }
            size++;
        }
    } catch (FileNotFoundException e) {
        throw new EncoderException("Unable to find file to encode");
    } catch (IOException e) {
        throw new EncoderException("Unable to read file to encode");
    }

}

From source file:PNGDecoder.java

protected static boolean verifyCRC(byte[] typeBytes, byte[] data, long crc) {
    CRC32 crc32 = new CRC32();
    crc32.update(typeBytes);/* www  .  j a v a 2 s  . c om*/
    crc32.update(data);
    long calculated = crc32.getValue();
    return (calculated == crc);
}