// collectiontopics/SortedMapDemo.java // (c)2020 MindView LLC: see Copyright.txt // We make no guarantees that this code is fit for any purpose. // Visit http://OnJava8.com for more book information. // What you can do with a TreeMap import java.util.*; import onjava.*; public class SortedMapDemo { public static void main(String[] args) { TreeMap sortedMap = new TreeMap<>(new CountMap(10)); System.out.println(sortedMap); Integer low = sortedMap.firstKey(); Integer high = sortedMap.lastKey(); System.out.println(low); System.out.println(high); Iterator it = sortedMap.keySet().iterator(); for(int i = 0; i <= 6; i++) { if(i == 3) low = it.next(); if(i == 6) high = it.next(); else it.next(); } System.out.println(low); System.out.println(high); System.out.println(sortedMap.subMap(low, high)); System.out.println(sortedMap.headMap(high)); System.out.println(sortedMap.tailMap(low)); } } /* Output: {0=A0, 1=B0, 2=C0, 3=D0, 4=E0, 5=F0, 6=G0, 7=H0, 8=I0, 9=J0} 0 9 3 7 {3=D0, 4=E0, 5=F0, 6=G0} {0=A0, 1=B0, 2=C0, 3=D0, 4=E0, 5=F0, 6=G0} {3=D0, 4=E0, 5=F0, 6=G0, 7=H0, 8=I0, 9=J0} */