【JavaDemo】使用Entry遍历含自定义类的Map集合

//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 + "]";
}

}

import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

/*
* 使用Map遍历自定义类型
*      遍历方式：方法2，取出Map中所有的键值对对象Entry，根据Entry对象获取key和value。
*/
public class MapDemo2 {

public static void main(String[] args) {

//定义Singer对象
Singer s1 = new Singer("田馥甄","小幸运");
Singer s2 = new Singer("孙燕姿","天黑黑");
Singer s3 = new Singer("周杰伦","晴天");
Singer s4 = new Singer("不   才","你有没有见过他");

//定义一个Map
Map<String,Singer> map = new HashMap<>();

//将Singer对象添加到Map中
map.put("001", s1);
map.put("002", s2);
map.put("003", s3);
map.put("004", s4);

//获取Entry对象
Set<Entry<String, Singer>> entrySet = map.entrySet();

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

//遍历每个Entry对象，通过Entry对象获取对应的歌手姓名和歌曲名称
for (Entry<String, Singer> entry : entrySet) {

System.out.println("\t\t"+entry.getKey()+"\t\t"+entry.getValue().getName()+"\t\t"+entry.getValue().getSongName());
}

}

}