Java Utililty Methods Checksum Calculate

List of utility methods to do Checksum Calculate

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Description

The list of methods to do Checksum Calculate are organized into topic(s).

Method

bytecheckSum(byte value)
check Sum 
return (byte) (value ^ (-1));
longcheckSum(byte[] b, int offset, int length)
Calculate an OpenType checksum from the array. 
long checkSum = 0;
for (int i = offset; i < length; i += 4) {
    for (int j = 0; j < 4; j++) {
        if (j + i < length) {
            checkSum += (b[j + i] & 0xff) << (24 - 8 * j);
return checkSum & 0xffffffffL;
intchecksum(byte[] buf, int off, int len)
checksum 
return update(buf, off, len) ^ 0xFFFFFFFF;
longchecksum(byte[] data)
Calculated the checksum of the given data array as a long value. 
long crc64Number = 0;
for (int i = 0; i < data.length; ++i) {
    int symbol = data[i];
    long a = (crc64Number >>> 8);
    long b = (crc64Number ^ symbol) & 0xff;
    crc64Number = a ^ _crc64Array[(int) b];
return crc64Number;
...
shortchecksum(byte[] message, int offset, int count)
Standard internet checksum algorithm shared by IP, ICMP, UDP and TCP. 
int sum = 0, cursor = 0;
while (cursor < count - 1) {
    sum += (int) integralFromBytes(message, offset + cursor, 2);
    cursor += 2;
if (cursor == count - 1) {
    sum += (message[offset + cursor] >= 0 ? message[offset + cursor]
            : message[offset + cursor] ^ 0xffffff00) << 8;
...
Stringchecksum(File file)
checksum 
String checksum;
try {
    checksum = com.google.common.io.Files.hash(file, Hashing.md5()).toString();
} catch (IOException e) {
    throw Throwables.propagate(e);
return checksum;
longchecksum(File file)
Get checksum value of a file. 
FileInputStream fInStream = new FileInputStream(file);
CheckedInputStream cInStream = new CheckedInputStream(fInStream, new CRC32());
BufferedInputStream bInStream = new BufferedInputStream(cInStream);
while (bInStream.read() != -1) {
return cInStream.getChecksum().getValue();
longchecksum(InputStream is)
Compute a checksum for the file or directory that consists of the name, length and the last modified date for a file and its children in case of a directory 
CRC32 crc = new CRC32();
byte[] buffer = new byte[8192];
int l;
while ((l = is.read(buffer)) > 0) {
    crc.update(buffer, 0, l);
return crc.getValue();
longchecksum(InputStream is)
Compute a checksum for the file or directory that consists of the name, length and the last modified date for a file and its children in case of a directory 
try {
    CRC32 crc = new CRC32();
    byte[] buffer = new byte[8192];
    int l;
    while ((l = is.read(buffer)) > 0) {
        crc.update(buffer, 0, l);
    return crc.getValue();
...
longchecksum(String filename)
Calculate a checksum for a file, based on the Adler32 algorithm invented by Mark Adler. 
CheckedInputStream cis = new CheckedInputStream(new FileInputStream(filename), new Adler32());
byte[] buffer = new byte[128];
while (cis.read(buffer) >= 0)
    continue;
return cis.getChecksum().getValue();