含有自定義類的Map遍歷 Demo2

• 此Demo演示方法2：獲取鍵值對物件Entry，然後用Entry分別鍵獲取鍵和值。
• Map含有自定義類Singer。
  

自定義類Singer

//歌手類
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 + "]";
}


}

遍歷類MapDemo2

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

/*
 * 使用Map遍歷自定義型別
 *      遍歷方式：方法2，取出Map中所有的鍵值對物件Entry，根據Entry物件獲取key和value。
 */
public
 
 class MapDemo2 {

    public static void main(String[] args) {

        //定義Singer物件
        Singer s1 = new Singer("田馥甄","小幸運");
        Singer s2 = new Singer("孫燕姿","天黑黑");
        Singer s3 = new Singer("周杰倫","晴天");
        Singer s4 = new Singer("不   才","你有沒有見過他");

        //定義一個Map
        Map<String,Singer> map = new HashMap<>();

        //將Singer物件新增到Map中
        map.put("001", s1);
        map.put("002", s2);
        map.put("003", s3);
        map.put("004", s4);

        //獲取Entry物件
        Set<Entry<String, Singer>> entrySet = map.entrySet();

        //列印標題
        System.out.println("\t\t"+"編號"+"\t\t"+"姓名"+"\t\t\t\t"+"歌曲");

        //遍歷每個Entry物件，通過Entry物件獲取對應的歌手姓名和歌曲名稱
        for (Entry<String, Singer> entry : entrySet) {

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

    }

}