
import java.util.SortedSet;
import java.util.TreeSet;
public class Test {
public static void main(String[] args) {
SortedSet<Integer> treeSet = new TreeSet<Integer>();
for (int i = 0; i < 10; i++) {
treeSet.add(i);
}
System.out.println("第一个元素:" + treeSet.first());
System.out.println("最后一个元素:" + treeSet.last());
System.out.println("4前面的元素:" + treeSet.headSet(4));
System.out.println("6后面的元素:" + treeSet.tailSet(6));
System.out.println("2-8之间元素:" + treeSet.subSet(2, 8));
}
}


