Mega Code Archive
List and Comparators
<![CDATA[
import java.util.*;
public class CompTest {
public static void main(String args[]) {
ArrayList u2 = new ArrayList();
u2.add("Beautiful Day");
u2.add("Stuck In A Moment You Can't Get Out Of");
u2.add("Elevation");
u2.add("Walk On");
u2.add("Kite");
u2.add("In A Little While");
u2.add("Wild Honey");
u2.add("Peace On Earth");
u2.add("When I Look At The World");
u2.add("New York");
u2.add("Grace");
Comparator comp = Comparators.stringComparator();
Collections.sort(u2, comp);
System.out.println(u2);
Arrays.sort(args, comp);
System.out.print("[");
for (int i=0, n=args.length; i<n; i++) {
if (i != 0) System.out.print(", ");
System.out.print(args[i]);
}
System.out.println("]");
}
}
class Comparators {
public static Comparator stringComparator() {
return new Comparator() {
public int compare(Object o1, Object o2) {
String s1 = (String)o1;
String s2 = (String)o2;
int len1 = s1.length();
int len2 = s2.length();
int n = Math.min(len1, len2);
char v1[] = s1.toCharArray();
char v2[] = s2.toCharArray();
int pos = 0;
while (n-- != 0) {
char c1 = v1[pos];
char c2 = v2[pos];
if (c1 != c2) {
return c1 - c2;
}
pos++;
}
return len1 - len2;
}
};
}
public static Comparator integerComparator() {
return new Comparator() {
public int compare(Object o1, Object o2) {
int val1 = ((Integer)o1).intValue();
int val2 = ((Integer)o2).intValue();
return (val1<val2 ? -1 : (val1==val2 ? 0 : 1));
}
};
}
public static Comparator dateComparator() {
return new Comparator() {
public int compare(Object o1, Object o2) {
long val1 = ((Date)o1).getTime();
long val2 = ((Date)o2).getTime();
return (val1<val2 ? -1 : (val1==val2 ? 0 : 1));
}
};
}
}
]]>