org.butor.utils

Class ObjectUtil

java.lang.Object

org.butor.utils.ObjectUtil

public class ObjectUtil
extends Object

Utility class for Objects

Author:

jdemers

Constructor Summary

Constructors

Constructor and Description
ObjectUtil()

Method Summary

Modifier and Type	Method and Description
static <T,U extends T> boolean	eq(T o1, U o2) Most of the time, we want to use o1.equals(o2) with objects of the same type.

Methods inherited from class java.lang.Object

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

Constructor Detail

ObjectUtil

public ObjectUtil()

Method Detail

eq

public static <T,U extends T> boolean eq(T o1,
                                         U o2)

Most of the time, we want to use o1.equals(o2) with objects of the same type. For instance: return aDate.equals(foo.getTime()); In our example, foo.getTime() returns a Date, which is fine. Lets say we refactor the code and decide getTime() will return a Long (millis) instead. The code above is now broken (it always return false), but it will compile without error and it will also execute without throwing exception at runtime. That kind of bug can be very costly to find and fix. It would be great if the compiler could tell us that we are using incompatible types. The function below does just that. Static typing is a great feature of the Java language. However, IMHO the function Object.equals(Object) was badly designed from the very beginning of Java and we now have to live with it. We do not need to have the method equals() and hascode() in the Object class. Classes that support that feature should implement the interface Equalable (just like Comparable).

Type Parameters:

T - an object

U - an object extends T

Parameters:

o1 - object

o2 - object

Returns:

boolean true if o1 equals o2 and are of the same type, false otherwise