从哈希映射返回与今天日期匹配的键值对

我有一个包含3个参数的哈希映射 aName aDate aTime

我有一个WhatsOn方法,我正在尝试配置它,如果今天实际上是今天,它将仅以文本形式打印今天的键值对。(并忽略所有其他键值对)

我想知道这是通过使用date类进行迭代来实现的,还是可以不用date类来实现。我的两门课如下:

WhatsOn公司。JAVA

import java.util.*;

public class WhatsOn {

    public static void main(String[] args) {

        WhatsOn alexa; // create an instance of the WhatsOn class

        alexa = new WhatsOn();

        alexa.addActivity("wash car","010117","0900");
        alexa.addActivity("go shopping","020117","1000");
        alexa.addActivity("return sale items","010117","1000");
        alexa.addActivity("Its saturday, just relax", "140418", "0900");

        for (Map.Entry<Integer,Activity> entry: activities.entrySet()) {
            String key = entry.getKey().toString();
            String value = entry.getValue().toString();
            System.out.println(key + " " + value);
        }
    }

    //instance variables for WhatsOn class

    private String today;
    private int nextId;
    private static Map<Integer, Activity> activities;

    // the constructor for the WhatsOn class

    public WhatsOn() {
        activities = new HashMap<Integer, Activity>();
        today = "010117";
        nextId = 1;
        System.out.println("if you see this, the constructor is working");
    }

    // This method should create an instance of Activity class  and then add it to the map referenced by the current value of nextId as the key

    public void addActivity (String aName, String aDate, String aTime) {

        Activity actToAdd = new Activity(aName, aDate, aTime); //create a new instance of the activity called actToAdd, this is a local var that stores methods arguments

        activities.put(nextId, actToAdd); //Add this instance to your Map

        nextId++; //increase the nextId    
    }

    public void whatsOnToday () {

     // needs configured

    }
}

活动JAVA

public class Activity {

    private String name;
    private String date;
    private String time;

    //constructor

    Activity(String name, String date, String time) {
        this.name = name;
        this.date = date;
        this.time = time;
    }

    //to string method
    public String toString(){
        return getName() + getDate() + getTime();
    }

    //getters and setters
    public void setDate(String aDate) {
        this.date = aDate;
    }

    public void setTime(String aTime) {
        this.time = aTime;
    }

    public void setName(String aName) {
        this.name = aName;
    }

    public String getDate() {
        return this.date;
    }

    public String getTime() {
        return this.time;
    }

    public String getName() {
        return this.name;
    }
}