java.util.zip

## Class CRC32

- java.lang.Object
- - java.util.zip.CRC32

- All Implemented Interfaces:
    Checksum

      public class CRC32
      extends Object
      implements Checksum

  Computes CRC32 data checksum of a data stream. The actual CRC32 algorithm is described in RFC 1952 (GZIP file format specification version 4.3). Can be used to get the CRC32 over a stream if used with checked input/output streams.
  Author:
    Per Bothner
  See Also:
    `InflaterInputStream`, `DeflaterOutputStream`

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `CRC32()`

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `long` | `getValue()` Returns the CRC32 data checksum computed so far.
    `void` | `reset()` Resets the CRC32 data checksum as if no update was ever called.
    `void` | `update(byte[] buf)` Adds the complete byte array to the data checksum.
    `void` | `update(byte[] buf, int off, int len)` Adds the byte array to the data checksum.
    `void` | `update(int bval)` Updates the checksum with the int bval.

    - ### Methods inherited from class java.lang.Object

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

- - ### Constructor Detail

    - #### CRC32

          public CRC32()

  - ### Method Detail

    - #### getValue

          public long getValue()

      Returns the CRC32 data checksum computed so far.
      Specified by:
        `getValue` in interface `Checksum`
      Returns:
        the current checksum value

    - #### reset

          public void reset()

      Resets the CRC32 data checksum as if no update was ever called.
      Specified by:
        `reset` in interface `Checksum`

    - #### update

          public void update(int bval)

      Updates the checksum with the int bval.
      Specified by:
        `update` in interface `Checksum`
      Parameters:
        `bval` - (the byte is taken as the lower 8 bits of bval)

    - #### update

          public void update(byte[] buf,
                             int off,
                             int len)

      Adds the byte array to the data checksum.
      Specified by:
        `update` in interface `Checksum`
      Parameters:
        `buf` - the buffer which contains the data
        `off` - the offset in the buffer where the data starts
        `len` - the length of the data

    - #### update

          public void update(byte[] buf)

      Adds the complete byte array to the data checksum.

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