Package org.opennms.protocols.ip

Class OC16ChecksumProducer

java.lang.Object
org.opennms.protocols.ip.OC16ChecksumProducer
public final class OC16ChecksumProducer extends Object
Produces a one's compliment 16-bit checksum from data that is "added" to the sum. The producer handles objects from 8-bits to 64-bit values.
Author:
Brian Weaver

  • Constructor Summary

    Constructors
    Constructor
    Description
    OC16ChecksumProducer()
    Default constructor.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    add(byte b)
    Adds the specified 8-bit value to the checksum.
    void
    add(byte a, byte b)
    Adds the specified 8-bit values to the checksum.
    void
    add(int i)
    Adds the specified 32-bit value to the checksum.
    void
    add(long l)
    Adds the specified 64-bit value to the checksum.
    void
    add(short s)
    Adds the specified 16-bit value to the checksum total.
    short
    getChecksum()
    Returns the current checksum value that has been computed for the object.
    void
    reset()
    Resets the object to a zero state.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • OC16ChecksumProducer

      public OC16ChecksumProducer()
      Default constructor.

  • Method Details

    • add

      public void add(byte b)
      Adds the specified 8-bit value to the checksum. Since the checksum must be in 16-bits, the byte is copied to the upper 8-bits of the 16-bit value. The lower 8-bits are set to zero.
      Parameters:
      b - The 8-bit value to add to the checksum.

    • add

      public void add(byte a, byte b)
      Adds the specified 8-bit values to the checksum. The checksum is performed using 16-bit values, thus the first byte is places into the high 8-bits of the word. The second byte is placed into the lower 8-bits of the 16-bit word. Then the result is added to the 16-bit checksum.
      Parameters:
      a - The high order 8-bits
      b - The low order 8-bits

    • add

      public void add(short s)
      Adds the specified 16-bit value to the checksum total.
      Parameters:
      s - The 16-bit value to add

    • add

      public void add(int i)
      Adds the specified 32-bit value to the checksum. The 32-bit value is broken into two 16-bit values for the purpose of computing the checksum.
      Parameters:
      i - The 32-bit value.

    • add

      public void add(long l)
      Adds the specified 64-bit value to the checksum. The 64-bit value is split into 4 16-bit quantities and added to the checksum.
      Parameters:
      l - The 64-bit value to add

    • reset

      public void reset()
      Resets the object to a zero state.

    • getChecksum

      public short getChecksum()
      Returns the current checksum value that has been computed for the object.
      Returns:
      The 16-bit ones compliment checksum