Module java.base
Package java.util.zip

Class CRC32

java.lang.Object
java.util.zip.CRC32
All Implemented Interfaces:
Checksum
public class CRC32
extends Object
implements Checksum
A class that can be used to compute the CRC-32 of a data stream.

Passing a null argument to a method in this class will cause a NullPointerException to be thrown.

Since:
1.1

  • Constructor Summary

    Constructors 
    Constructor Description
    CRC32()
    Creates a new CRC32 object.

  • Method Summary

    Modifier and Type Method Description
    long getValue()
    Returns CRC-32 value.
    void reset()
    Resets CRC-32 to initial value.
    void update​(byte[] b, int off, int len)
    Updates the CRC-32 checksum with the specified array of bytes.
    void update​(int b)
    Updates the CRC-32 checksum with the specified byte (the low eight bits of the argument b).
    void update​(ByteBuffer buffer)
    Updates the CRC-32 checksum with the bytes from the specified buffer.

    Methods declared in class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    Methods declared in interface java.util.zip.Checksum

    update

  • Constructor Details

    • CRC32

      public CRC32()
      Creates a new CRC32 object.

  • Method Details

    • update

      public void update​(int b)
      Updates the CRC-32 checksum with the specified byte (the low eight bits of the argument b).
      Specified by:
      update in interface Checksum
      Parameters:
      b - the byte to update the checksum with

    • update

      public void update​(byte[] b, int off, int len)
      Updates the CRC-32 checksum with the specified array of bytes.
      Specified by:
      update in interface Checksum
      Parameters:
      b - the byte array to update the checksum with
      off - the start offset of the data
      len - the number of bytes to use for the update
      Throws:
      ArrayIndexOutOfBoundsException - if off is negative, or len is negative, or off+len is negative or greater than the length of the array b.

    • update

      public void update​(ByteBuffer buffer)
      Updates the CRC-32 checksum with the bytes from the specified buffer. The checksum is updated with the remaining bytes in the buffer, starting at the buffer's position. Upon return, the buffer's position will be updated to its limit; its limit will not have been changed.
      Specified by:
      update in interface Checksum
      Parameters:
      buffer - the ByteBuffer to update the checksum with
      Since:
      1.8

    • reset

      public void reset()
      Resets CRC-32 to initial value.
      Specified by:
      reset in interface Checksum

    • getValue

      public long getValue()
      Returns CRC-32 value.
      Specified by:
      getValue in interface Checksum
      Returns:
      the current checksum value