Map

 1 public class Emp {
 2     private String e_id;
 3     private String e_name;
 4 
 5     public Emp(String e_id, String e_name) {
 6         this.e_id = e_id;
 7         this.e_name = e_name;
 8     }
 9 
10     public String getE_id() {
11         return e_id;
12     }
13 
14     public void setE_id(String e_id) {
15         this.e_id = e_id;
16     }
17 
18     public String getE_name() {
19         return e_name;
20     }
21 
22     public void setE_name(String e_name) {
23         this.e_name = e_name;
24     }
25 
26 }

 1 import java.util.*;
 2 
 3 public class MapText {
 4 
 5     public static void main(String[] args) {
 6         Map<String,String> map = new HashMap<>();
 7         Emp emp = new Emp("001", "张三");
 8         Emp emp1 = new Emp("002", "李四");
 9         Emp emp2 = new Emp("005", "王五");
10         Emp emp3 = new Emp("006", "马六");
11         map.put(emp.getE_id(), emp.getE_name());
12         map.put(emp1.getE_id(), emp1.getE_name());
13         map.put(emp2.getE_id(), emp2.getE_name());
14         map.put(emp3.getE_id(), emp3.getE_name());
15 
16         System.out.println("HashMap类实现的map集合，无序：");
17         for (String str : map.keySet()) {
18             System.out.println(str + ":" + map.get(str));
19         }
20         System.out.println("HashMap类实现的map集合，有序：");
21         TreeMap<String,String> tmap = new TreeMap<>();
22         tmap.putAll(map);
23         for (String str : tmap.keySet()) {
24             System.out.println(str + ":" + tmap.get(str));
25         }
26 
27         map.remove("005");
28         System.out.println(map);
29         tmap.remove("005");
30         System.out.println(tmap);
31     }
32 
33 }

运行：