java.lang.Comparable Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
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*/
package java.lang;
/**
* This interface should be implemented by all classes that wish to define a
* natural order of their instances.
* {@link java.util.Collections#sort} and {@code java.util.Arrays#sort} can then
* be used to automatically sort lists of classes that implement this interface.
*
* The order rule must be both transitive (if {@code x.compareTo(y) < 0} and
* {@code y.compareTo(z) < 0}, then {@code x.compareTo(z) < 0} must hold) and
* invertible (the sign of the result of x.compareTo(y) must be equal to the
* negation of the sign of the result of y.compareTo(x) for all combinations of
* x and y).
*
* In addition, it is recommended (but not required) that if and only if the
* result of x.compareTo(y) is zero, then the result of x.equals(y) should be
* {@code true}.
*/
public interface Comparable {
/**
* Compares this object to the specified object to determine their relative
* order.
*
* @param another
* the object to compare to this instance.
* @return a negative integer if this instance is less than {@code another};
* a positive integer if this instance is greater than
* {@code another}; 0 if this instance has the same order as
* {@code another}.
* @throws ClassCastException
* if {@code another} cannot be converted into something
* comparable to {@code this} instance.
*/
int compareTo(T another);
}