【JavaDemo】使用key遍历含自定义类的Map集合

含有自定义类的Map遍历 Demo1

• 此Demo演示方法1：先获取所有的键key的Set集合，然后根据键获取值。
• Map含有自定义类Singer。

自定义类Singer

//歌手类
public class Singer {
private String name;
private String songName;
public Singer(String name, String songName) {
    super();
    this.name = name;
    this.songName = songName;
}
public Singer() {
    super();
    // TODO Auto-generated constructor stub
}
public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}
public String getSongName() {
    return songName;
}
public void setSongName(String songName) {
    this.songName = songName;
}
@Override
public String toString() {
    return "Singer [name=" + name + ", songName=" + songName + "]";
}


}

遍历类MapDemo

import java.util.HashMap;
import java.util.Map;
import java.util.Set;
/*
 * 使用Map遍历自定义类型
 *      遍历方式：方法1，取出Map中所有的key，根据key获取值。
 */
public class MapDemo {
public static void main(String[] args) {
    //创建歌手
    Singer s1 = new Singer("邓紫棋", "泡沫");
    Singer s2 = new Singer("银   临", "牵丝戏");
    Singer s3 = new Singer("谢春花", "只道寻常");
    Singer s4 = new Singer("Taylor", "TikTok");

    Map map = new HashMap<>();
    map.put("001",s1);
    map.put("002",s2);
    map.put("003",s3);
    map.put("004",s4);

    //获取key集合
    Set keySet = map.keySet();

    //打印输出
    System.out.println("\t"+"编号"+"\t\t"+"姓名"+"\t\t\t"+"歌曲");

    //遍历key,并通过key获取Singer对象。然后通过这个对象获取歌手姓名和歌曲名
    for (String key : keySet) {
        System.out.println("\t"+key+"\t\t"+map.get(key).getName()+"\t\t"+map.get(key).getSongName());

    }

}
}