init

day01/src/com/inmind/TreeSetDemo1.java

@@ -0,0 +1,42 @@
+package com.inmind;
+
+import com.inmind.test07.Student;
+
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.TreeMap;
+import java.util.TreeSet;
+
+public class TreeSetDemo1 {
+    public static void main(String[] args) {
+        TreeSet<Student> treeSet = new TreeSet<>(new Comparator<Student>() {
+
+            @Override
+            public int compare(Student o1, Student o2) {
+                return o2.getId() - o1.getId();
+            }
+        });
+        Student s1 = new Student();
+        s1.setId(1);
+        Student s2 = new Student();
+        s2.setId(3);
+        Student s3 = new Student();
+        s3.setId(5);
+        treeSet.add(s1);
+        treeSet.add(s2);
+        treeSet.add(s3);
+        System.out.println(treeSet);
+
+        TreeMap<Student, String> treeMap = new TreeMap<>(new Comparator<Student>() {
+            @Override
+            public int compare(Student o1, Student o2) {
+                return o2.getId() - o1.getId();
+            }
+        });
+        treeMap.put(s1, "<UNK>");
+        treeMap.put(s2, "<UNK>");
+        treeMap.put(s3, "<UNK>");
+
+        System.out.println(treeMap);
+    }
+}