org.jfree.util

Class ClassComparator

java.lang.Object

org.jfree.util.ClassComparator

All Implemented Interfaces:

Serializable, Comparator

public class ClassComparator
extends Object
implements Comparator, Serializable

The class comparator can be used to compare and sort classes and their superclasses. The comparator is not able to compare classes which have no relation...

Author:

Thomas Morgner

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ClassComparator() Defaultconstructor.

Method Summary

Methods

Modifier and Type	Method and Description
int	compare(Object o1, Object o2) Compares its two arguments for order.
boolean	isComparable(Class c1, Class c2) Checks, whether the given classes are comparable.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

equals

Constructor Detail

ClassComparator

public ClassComparator()

Defaultconstructor.

Method Detail

compare

public int compare(Object o1,
          Object o2)

Compares its two arguments for order. Returns a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

Note: throws ClassCastException if the arguments' types prevent them from being compared by this Comparator. And IllegalArgumentException if the classes share no relation. The implementor must ensure that sgn(compare(x, y)) == -sgn(compare(y, x)) for all x and y. (This implies that compare(x, y) must throw an exception if and only if compare(y, x) throws an exception.)

The implementor must also ensure that the relation is transitive: ((compare(x, y)>0) && (compare(y, z)>0)) implies compare(x, z)>0.

Finally, the implementer must ensure that compare(x, y)==0 implies that sgn(compare(x, z))==sgn(compare(y, z)) for all z.

It is generally the case, but not strictly required that (compare(x, y)==0) == (x.equals(y)). Generally speaking, any comparator that violates this condition should clearly indicate this fact. The recommended language is "Note: this comparator imposes orderings that are inconsistent with equals."

Specified by:

compare in interface Comparator

Parameters:

o1 - the first object to be compared.

o2 - the second object to be compared.

Returns:

a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

isComparable

public boolean isComparable(Class c1,
                   Class c2)

Checks, whether the given classes are comparable. This method will return true, if one of the classes is assignable from the other class.

Parameters:

c1 - the first class to compare

c2 - the second class to compare

Returns:

true, if the classes share a direct relation, false otherwise.