ucar.unidata.util

Class HashCodeUtils

java.lang.Object

ucar.unidata.util.HashCodeUtils

public class HashCodeUtils
extends java.lang.Object

Taken from http://www.javapractices.com/Topic28.cjp.

Collected methods which allow easy implementation of hashCode.

Example use case.

  public int hashCode(){
    int result = HashCodeUtil.SEED;
    //collect the contributions of various fields
    result = HashCodeUtil.hash(result, fPrimitive);
    result = HashCodeUtil.hash(result, fObject);
    result = HashCodeUtil.hash(result, fArray);
    return result;
  }
 

Field Summary

Fields

Modifier and Type	Field and Description
static int	SEED An initial value for a hashCode, to which is added contributions from fields.

Constructor Summary

Constructors

Constructor and Description
HashCodeUtils()

Method Summary

Modifier and Type	Method and Description
static int	hash(int aSeed, boolean aBoolean) booleans.
static int	hash(int aSeed, char aChar) chars.
static int	hash(int aSeed, double aDouble) doubles.
static int	hash(int aSeed, float aFloat) floats.
static int	hash(int aSeed, int aInt) ints.
static int	hash(int aSeed, long aLong) longs.

Methods inherited from class java.lang.Object

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

Field Detail

SEED

public static final int SEED

An initial value for a hashCode, to which is added contributions from fields. Using a non-zero value decreases collisons of hashCode values.

See Also:

Constant Field Values

Constructor Detail

HashCodeUtils

public HashCodeUtils()

Method Detail

hash

public static int hash(int aSeed,
                       boolean aBoolean)

booleans.

Parameters:

aSeed - _more_

aBoolean - _more_

Returns:

_more_

hash

public static int hash(int aSeed,
                       char aChar)

chars.

Parameters:

aSeed - _more_

aChar - _more_

Returns:

_more_

hash

public static int hash(int aSeed,
                       int aInt)

ints.

Parameters:

aSeed - _more_

aInt - _more_

Returns:

_more_

hash

public static int hash(int aSeed,
                       long aLong)

longs.

Parameters:

aSeed - _more_

aLong - _more_

Returns:

_more_

hash

public static int hash(int aSeed,
                       float aFloat)

floats.

Parameters:

aSeed - _more_

aFloat - _more_

Returns:

_more_

hash

public static int hash(int aSeed,
                       double aDouble)

doubles.

Parameters:

aSeed - _more_

aDouble - _more_

Returns:

_more_