TreeMap:
package com;import java.util.Comparator;import java.util.TreeMap;public class Test5 {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubTreeMap<String, String> tree = new TreeMap<String, String>(new Comparator<Object>() {@Overridepublic int compare(Object o1, Object o2) {// TODO Auto-generated method stubif(o1 == null || o2 == null){return 0;}return o1.toString().compareTo(o2.toString());}});tree.put("k", "1");tree.put("ba", "2");tree.put("z", "3");tree.put("d", "4");tree.put("e", "5");tree.put("an", "6");tree.put("c", "7");for(String str : tree.keySet()){System.out.println(str);}}}By default, it is sorted by KEY.
However, you can write an object comparator to perform custom sorting.
TreeSet: Custom sorting in reverse order, default sorting in positive order, 1, 2, 3, 4, 5, 6
package com;import java.util.Comparator;import java.util.TreeSet;public class Test6 {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubTreeSet<Object> tree = new TreeSet<Object>(new Comparator<Object>() {@Overridepublic int compare(Object o1, Object o2) {// TODO Auto-generated method stubif(o1 == null || o2 == null){return 0;}if(Integer.parseInt(o1.toString()) > Integer.parseInt(o2.toString())){return -1;}else if(Integer.parseInt(o1.toString())) < Integer.parseInt(o2.toString())){return 1;}else{return 0;}}});tree.add(4);tree.add(5);tree.add(6);tree.add(1);tree.add(2);tree.add(3);for(Object o: tree){System.out.println(o);}}}The above article briefly discusses TreeMap sorting and TreeSet sorting in java are all the content I share with you. I hope you can give you a reference and I hope you can support Wulin.com more.