Mega Code Archive
Generic methods
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import java.util.Arrays;
import java.util.Collection;
import java.util.Comparator;
class Comparators {
public static <T> T max(Collection<? extends T> coll, Comparator<? super T> cmp) {
T candidate = coll.iterator().next();
for (T elt : coll) {
if (cmp.compare(candidate, elt) < 0) {
candidate = elt;
}
}
return candidate;
}
public static <T extends Comparable<? super T>> T max(Collection<? extends T> coll) {
return max(coll, Comparators.<T> naturalOrder());
}
public static <T> T min(Collection<? extends T> coll, Comparator<? super T> cmp) {
return max(coll, reverseOrder(cmp));
}
public static <T extends Comparable<? super T>> T min(Collection<? extends T> coll) {
return max(coll, Comparators.<T> reverseOrder());
}
public static <T extends Comparable<? super T>> Comparator<T> naturalOrder() {
return new Comparator<T>() {
public int compare(T o1, T o2) {
return o1.compareTo(o2);
}
};
}
public static <T> Comparator<T> reverseOrder(final Comparator<T> cmp) {
return new Comparator<T>() {
public int compare(T o1, T o2) {
return cmp.compare(o2, o1);
}
};
}
public static <T extends Comparable<? super T>> Comparator<T> reverseOrder() {
return new Comparator<T>() {
public int compare(T o1, T o2) {
return o2.compareTo(o1);
}
};
}
}
public class MainClass{
public static void main(String[] args) {
Comparator<String> sizeOrder = new Comparator<String>() {
public int compare(String s1, String s2) {
return s1.length() < s2.length() ? -1 : s1.length() > s2.length() ? 1 : s1.compareTo(s2);
}
};
Collection<String> strings = Arrays.asList("AAA", "aaa", "CCC", "f");
System.out.println(Comparators.max(strings));
System.out.println(Comparators.min(strings));
System.out.println(Comparators.max(strings,sizeOrder));
System.out.println(Comparators.min(strings,sizeOrder));
}
}
f
AAA
aaa
f
]]>