Checksum (Java Platform SE 8 )
Keywords: java.util.zip.Checksum interface
Date: 2026-07-22

compact1, compact2, compact3
java.util.zip

## Interface Checksum

- All Known Implementing Classes:
    Adler32, CRC32

      public interface Checksum

  An interface representing a data checksum.

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method and Description
    --- | ---
    `long` | `getValue()` Returns the current checksum value.
    `void` | `reset()` Resets the checksum to its initial value.
    `void` | `update(byte[] b, int off, int len)` Updates the current checksum with the specified array of bytes.
    `void` | `update(int b)` Updates the current checksum with the specified byte.

- - ### Method Detail

    - #### update

          void update(int b)

      Updates the current checksum with the specified byte.
      Parameters:
        `b` - the byte to update the checksum with

    - #### update

          void update(byte[] b,
                      int off,
                      int len)

      Updates the current checksum with the specified array of bytes.
      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

    - #### getValue

          long getValue()

      Returns the current checksum value.
      Returns:
        the current checksum value

    - #### reset

          void reset()

      Resets the checksum to its initial value.

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