Package com.webmethods.caf.wsclient.util

Class HashCodeUtil

java.lang.Object
com.webmethods.caf.wsclient.util.HashCodeUtil
public final class HashCodeUtil extends Object
The following utility class allows simple construction of an effective hashCode method. It is based on the recommendations of Effective Java, by Joshua Bloch. 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
    Description
    static final int
    SEED
    An initial value for a hashCode, to which is added contributions from fields.

  • Constructor Summary

    Constructors
    Constructor
    Description
    HashCodeUtil()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static int
    hash(int aSeed, boolean aBoolean)
    Generate a hash for a boolean value
    static int
    hash(int aSeed, char aChar)
    Generate a hash for a char value
    static int
    hash(int aSeed, double aDouble)
    Generate a hash for a double value
    static int
    hash(int aSeed, float aFloat)
    Generate a hash for a float value
    static int
    hash(int aSeed, int aInt)
    Generate a hash for an integer value Note: byte and short are handled by this method, through implicit conversion.
    static int
    hash(int aSeed, long aLong)
    Generate a hash for a long value
    static int
    hash(int aSeed, Object aObject)
    Generate a hash for an Object instance

    Methods inherited from class java.lang.Object

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

  • Field Details

    • 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:

  • Constructor Details

    • HashCodeUtil

      public HashCodeUtil()

  • Method Details

    • hash

      public static int hash(int aSeed, boolean aBoolean)
      Generate a hash for a boolean value
      Parameters:
      aSeed - the initial hash value seed, used to aggregate a hash for multiple objects (see class description)
      aBoolean - boolean value to hash
      Returns:
      the aggregated hash code

    • hash

      public static int hash(int aSeed, char aChar)
      Generate a hash for a char value
      Parameters:
      aSeed - the initial hash value seed, used to aggregate a hash for multiple objects (see class description)
      aChar - char value to hash
      Returns:
      the aggregated hash code

    • hash

      public static int hash(int aSeed, int aInt)
      Generate a hash for an integer value Note: byte and short are handled by this method, through implicit conversion.
      Parameters:
      aSeed - the initial hash value seed, used to aggregate a hash for multiple objects (see class description)
      aInt - integer value to hash
      Returns:
      the aggregated hash code

    • hash

      public static int hash(int aSeed, long aLong)
      Generate a hash for a long value
      Parameters:
      aSeed - the initial hash value seed, used to aggregate a hash for multiple objects (see class description)
      aLong - long value to hash
      Returns:
      the aggregated hash code

    • hash

      public static int hash(int aSeed, float aFloat)
      Generate a hash for a float value
      Parameters:
      aSeed - the initial hash value seed, used to aggregate a hash for multiple objects (see class description)
      aFloat - float value to hash
      Returns:
      the aggregated hash code

    • hash

      public static int hash(int aSeed, double aDouble)
      Generate a hash for a double value
      Parameters:
      aSeed - the initial hash value seed, used to aggregate a hash for multiple objects (see class description)
      aDouble - double value to hash
      Returns:
      the aggregated hash code

    • hash

      public static int hash(int aSeed, Object aObject)
      Generate a hash for an Object instance
      Parameters:
      aSeed - the initial hash value seed, used to aggregate a hash for multiple objects (see class description)
      aObject - the Object instance to hash, this can include a null object or an array of objects
      Returns:
      the aggregated hash code