java中哈希表与有序表的使用

package class04P;

import java.util.Comparator;
import java.util.*;

public class Code01P_HashAndTree {

    public static class Node{
        public int value;
        public Node next;

        public Node(int vaule){
            this.value = value;
        }
    }

    public static class NodeComparator implements Comparator{
        @Override
        public int compare(Node o1, Node o2){
            return o1.value - o2.value;
        }
    }

    public static void main(String[] args){
        Node nodeA = null;
        Node nodeB = null;
        Node nodeC = null;

        HashSet hashSet1 = new HashSet<>();
        hashSet1.add(3);
        System.out.println(hashSet1.contains(3));
        hashSet1.remove(3);
        System.out.println(hashSet1.contains(3));
        System.out.println("============1=============");

        nodeA = new Node(1);
        nodeB = new Node(1);
        HashSet hashSet2= new HashSet<>();
        hashSet2.add(nodeA);
        System.out.println(hashSet2.contains(nodeA));
        System.out.println(hashSet2.contains(nodeB));
        hashSet2.remove(nodeA);
        System.out.println(hashSet2.contains(nodeA));
        System.out.println("========2=========");

        HashMap hashMap1 = new HashMap<>();
        String str1 = "key";
        String str2 = "key";
        hashMap1.put(str1, 1);
        System.out.println(hashMap1.containsKey(str1));
        System.out.println(hashMap1.containsKey(str2));
        System.out.println(hashMap1.get(str1));
        System.out.println(hashMap1.get(str2));

        hashMap1.put(str2, 2);
        System.out.println(hashMap1.containsKey(str1));
        System.out.println(hashMap1.containsKey(str2));
        System.out.println(hashMap1.get(str1));
        System.out.println(hashMap1.get(str2));

        hashMap1.remove(str1);
        System.out.println(hashMap1.containsKey(str1));
        System.out.println(hashMap1.containsKey(str2));
        System.out.println("========3=========");

        nodeA = new Node(1);
        nodeB = new Node(1);
        HashMap hashMap2 = new HashMap<>();
        hashMap2.put(nodeA, "A节点");
        System.out.println(hashMap2.containsKey(nodeA));
        System.out.println(hashMap2.containsKey(nodeB));
        System.out.println(hashMap2.get(nodeA));
        System.out.println(hashMap2.get(nodeB));
        hashMap2.put(nodeB, "B节点");
        System.out.println(hashMap2.containsKey(nodeA));
        System.out.println(hashMap2.containsKey(nodeB));
        System.out.println(hashMap2.get(nodeA));
        System.out.println(hashMap2.get(nodeB));
        System.out.println("========4=========");

        nodeA = new Node(5);
        nodeB = new Node(3);
        nodeC = new Node(7);

        TreeSet treeSet = new TreeSet<>();
        // 以下的代码会报错，因为没有提供Node类型的比较器
        try {
            treeSet.add(nodeA);
            treeSet.add(nodeB);
            treeSet.add(nodeC);
        } catch (Exception e) {
            System.out.println("错误信息：" + e.getMessage());
        }
        treeSet = new TreeSet<>(new NodeComparator());
        // 以下的代码没问题，因为提供了Node类型的比较器

        try{
            treeSet.add(nodeA);
            treeSet.add(nodeB);
            treeSet.add(nodeC);
            System.out.println("这次节点都加入了");
        }catch(Exception e){
            System.out.println(e.getMessage());
        }
        System.out.println("========5=========");
        TreeMap treeMap1 = new TreeMap<>();
        treeMap1.put(7, "我是7");
        treeMap1.put(5, "我是5");
        treeMap1.put(4, "我是4");
        treeMap1.put(3, "我是3");
        treeMap1.put(9, "我是9");
        treeMap1.put(2, "我是2");
        System.out.println(treeMap1.containsKey(5));
        System.out.println(treeMap1.get(5));
        System.out.println(treeMap1.firstKey());
        System.out.println(treeMap1.lastKey());
        System.out.println(treeMap1.floorKey(8));
        System.out.println(treeMap1.ceilingKey(8));
        treeMap1.remove(5);
        System.out.println(treeMap1.get(5));
        System.out.println("==========6=============");
    }

}