uk.org.lidalia.lang

Class RichObject

java.lang.Object

uk.org.lidalia.lang.RichObject

public abstract class RichObject
extends Object

A class that provides implementations of equals(Object), hashCode() and toString() for its subtypes.

These implementations are based on annotating the fields of the subtypes with the Identity annotation.

Constructor Summary

Constructors

Constructor and Description
RichObject()

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object other) Implementation of equals based on fields annotated with Identity.
int	hashCode() Default implementation of hashCode - can be overridden to provide more efficient ones provided the contract specified in Object.hashCode() is maintained with respect to equals(Object).
String	toString() Default implementation of toString.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

RichObject

public RichObject()

Method Detail

equals

public final boolean equals(Object other)

Implementation of equals based on fields annotated with Identity. Applies equality rules on the following basis (in addition to the rules in Object.equals(Object)):

• other's runtime class must be the same, a super or a sub type of the runtime class of this instance
• other's runtime class must have exactly the same set of fields annotated with Identity as those on the runtime class of this instance, where the set of fields in each case comprises those on the class and all of its superclasses
• the value of any field annotated with Identity on this must be equal to the value of the same field on other

The practical result of this is that an instance of subtype B of subtype A of RichObject can only be equal to an instance of subtype A if B does not annotate any of its fields with Identity.

Overrides:

equals in class Object

Parameters:

other - the object to compare against

Returns:

true if the other type is logically equal to this

hashCode

public int hashCode()

Default implementation of hashCode - can be overridden to provide more efficient ones provided the contract specified in Object.hashCode() is maintained with respect to equals(Object).

Overrides:

hashCode in class Object

Returns:

hash code computed from the hashes of all the fields annotated with Identity

toString

public String toString()

Default implementation of toString.

Overrides:

toString in class Object

Returns:

a string in the form ClassName[field1=value1,field2=value2] where the fields are those annotated with Identity