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/**
* @version 1.00 1999-07-07
* @author Cay Horstmann
*/
import java.util.Comparator;
import java.util.SortedSet;
import java.util.TreeSet;
public class TreeSetTest {
public static void main(String[] args) {
SortedSet parts = new TreeSet();
parts.add(new Item("Toaster", 1234));
parts.add(new Item("Widget", 4562));
parts.add(new Item("Modem", 9912));
System.out.println(parts);
SortedSet sortByDescription = new TreeSet(new Comparator() {
public int compare(Object a, Object b) {
Item itemA = (Item) a;
Item itemB = (Item) b;
String descrA = itemA.getDescription();
String descrB = itemB.getDescription();
return descrA.compareTo(descrB);
}
});
sortByDescription.addAll(parts);
System.out.println(sortByDescription);
}
}
class Item implements Comparable {
public Item(String aDescription, int aPartNumber) {
description = aDescription;
partNumber = aPartNumber;
}
public String getDescription() {
return description;
}
public String toString() {
return "[descripion=" + description + ", partNumber=" + partNumber
+ "]";
}
public boolean equals(Object other) {
if (getClass() == other.getClass()) {
Item otherItem = (Item) other;
return description.equals(otherItem.description)
&& partNumber == otherItem.partNumber;
} else
return false;
}
public int hashCode() {
return 13 * description.hashCode() + 17 * partNumber;
}
public int compareTo(Object other) {
Item otherItem = (Item) other;
return partNumber - otherItem.partNumber;
}
private String description;
private int partNumber;
}
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