输入用户名查询是否存在

 1 import java.util.HashMap;
 2 import java.util.Map;
 3 import java.util.Scanner;
 4 import java.util.Set;
 5 
 6 public class UserTest {
 7 
 8     public static void main(String[] args) {
 9         Scanner sc=new Scanner(System.in);
10         System.out.println("请输入用户名：");
11         String uname=sc.next();
12         System.out.println("请输入密码：");
13         String passwd=sc.next();
14         User u=new User(uname,passwd);
15         Map<String,User> map=new HashMap<String,User>();
16         map.put("张三",new User("张三","123"));
17         map.put("李四",new User("李四","152"));
18         map.put("王五",new User("王五","432"));
19         map.put("赵六",new User("赵六","142"));
20         map.put("唐七",new User("唐七","846"));
21         Set<Map.Entry<String,User>> entries=map.entrySet();
22         boolean flags=false;
23         for(Map.Entry<String,User> e:entries){
24             if(e.getKey().equals(uname)&&e.getValue().getUsername().equals(uname)&&e.getValue().getPassword().equals(passwd)){//&&e.getValue().equals(e)
25                 System.out.println("含有该用户的信息！");
26                 flags=true;
27                 break;
28             }
29         }
30         if(flags==false){
31             System.out.println("系统未查询到该用户的信息！");
32         }
33     }
34 }
35 
36 class User {
37     String username;
38     String password;
39 
40     public User(String username, String password) {
41         super();
42         this.username = username;
43         this.password = password;
44     }
45 
46     public String getUsername() {
47         return username;
48     }
49 
50     public void setUsername(String username) {
51         this.username = username;
52     }
53 
54     public String getPassword() {
55         return password;
56     }
57 
58     public void setPassword(String password) {
59         this.password = password;
60     }
61 
62     @Override
63     public String toString() {
64         return "User [username=" + username + ", password=" + password + "]";
65     }
66 
67 }