/*
* @(#)CharSequenceComparator.java 7/15/2008
*
* Copyright 2002 - 2008 JIDE Software Inc. All rights reserved.
*
*/
package com.jidesoft.comparator;
import java.io.Serializable;
import java.util.Comparator;
/**
* A Comparator that compares CharSequence objects (including String and StringBuffer as both extend CharSequence.
* Throws ClassCastExceptions if the objects are not CharSequence, or if they are null. If both objects are null, they
* will be treated as equal. If one is null and the other is not, the null value will be treated as smaller then
* non-null value.
*/
public class CharSequenceComparator implements Comparator<Object>, Serializable {
private static final long serialVersionUID = -4749963150099170895L;
private boolean _caseSensitive;
public static final ComparatorContext CONTEXT = new ComparatorContext("IgnoreLocale");
public static final ComparatorContext CONTEXT_IGNORE_CASE = new ComparatorContext("IgnoreLocale_Ignorecase");
/**
* Constructs a CharSequenceComparator.
*/
public CharSequenceComparator() {
this(true);
}
public CharSequenceComparator(boolean caseSensitive) {
_caseSensitive = caseSensitive;
}
/**
* Checks if the case is sensitive when comparing.
*
* @return true if the comparator is case sensitive.
*/
public boolean isCaseSensitive() {
return _caseSensitive;
}
/**
* Sets the case sensitive flag. By default, it's true meaning the comparator is case sensitive.
*
* @param caseSensitive true or false.
*/
public void setCaseSensitive(boolean caseSensitive) {
_caseSensitive = caseSensitive;
}
public int compare(Object o1, Object o2) {
if (o1 == null && o2 == null) {
return 0;
}
else if (o1 == null) {
return -1;
}
else if (o2 == null) {
return 1;
}
if (o1 instanceof CharSequence) {
if (o2 instanceof CharSequence) {
CharSequence s1 = (CharSequence) o1;
CharSequence s2 = (CharSequence) o2;
return isCaseSensitive() ? compareCase(s1, s2) : compareIgnoreCase(s1, s2);
}
else {
// o2 wasn't comparable
throw new ClassCastException("The second argument of this method was not a CharSequence: " + o2.getClass().getName());
}
}
else if (o2 instanceof Comparable) {
// o1 wasn't comparable
throw new ClassCastException("The first argument of this method was not a CharSequence: " + o1.getClass().getName());
}
else {
// neither were comparable
throw new ClassCastException("Both arguments of this method were not CharSequences: " + o1.getClass().getName() + " and " + o2.getClass().getName());
}
}
private int compareCase(CharSequence s1, CharSequence s2) {
int len1 = s1.length();
int len2 = s2.length();
int n = Math.min(len1, len2);
int k = 0;
while (k < n) {
char c1 = s1.charAt(k);
char c2 = s2.charAt(k);
if (c1 != c2) {
return c1 - c2;
}
k++;
}
return len1 - len2;
}
private int compareIgnoreCase(CharSequence s1, CharSequence s2) {
int n1 = s1.length(), n2 = s2.length();
for (int i1 = 0, i2 = 0; i1 < n1 && i2 < n2; i1++, i2++) {
char c1 = s1.charAt(i1);
char c2 = s2.charAt(i2);
if (c1 != c2) {
c1 = Character.toUpperCase(c1);
c2 = Character.toUpperCase(c2);
if (c1 != c2) {
c1 = Character.toLowerCase(c1);
c2 = Character.toLowerCase(c2);
if (c1 != c2) {
return c1 - c2;
}
}
}
}
return n1 - n2;
}
// /**
// * * sort a set of string from stdin
// */
// public static void main(String[] args) {
// try {
// Vector<String> v = new Vector<String>();
// for (int i = 0; i < 1; i++) {
// v.add("a1");
// v.add("A2");
// v.add("a2");
// v.add("a10");
// v.add("a1c1");
// v.add("a1c2");
// v.add("a1c10");
// v.add("a1c20");
// v.add("a100");
// v.add("b3");
// v.add("c3");
// v.add("cc3");
// v.add("cc2");
// v.add("1.doc");
// v.add("2.doc");
// v.add("3.doc");
// v.add("4.doc");
// v.add("5.doc");
// v.add("6.doc");
// v.add("7.doc");
// v.add("8.doc");
// v.add("9.doc");
// v.add("10.doc");
// v.add("11.doc");
// v.add("12.doc");
// v.add("13.doc");
// v.add("14.doc");
// v.add("15.doc");
// v.add("16.doc");
// v.add("17.doc");
// v.add("18.doc");
// v.add("19.doc");
// v.add("20.doc");
// v.add("100.doc");
// v.add("101.doc");
// v.add("102.doc");
// }
// long start = System.nanoTime();
// Collections.sort(v, new CharSequenceComparator());
// long end = System.nanoTime();
// System.out.println(end - start);
// for (String s : v) System.out.println(s);
// }
// catch (Throwable error) {
// error.printStackTrace();
// System.exit(-1);
// }
// }
}