这段代码什么意思loginResult.setUserName(tenantsUser == null?loginUser.getUserName():tenantsUser.getUserName());
时间: 2024-04-06 10:31:19 浏览: 11
这段代码的意思是根据条件判断来设置`loginResult`对象的`userName`属性值。如果`tenantsUser`为`null`,则将`loginUser`的`userName`赋值给`loginResult`的`userName`属性;否则将`tenantsUser`的`userName`赋值给`loginResult`的`userName`属性。通俗一点说,就是先用`tenantsUser`的`userName`去设置`loginResult`的`userName`属性,如果`tenantsUser`为空,则用`loginUser`的`userName`去设置`loginResult`的`userName`属性。
相关问题
java用户管理系统代码
### 回答1:
以下是一个简单的 Java 用户管理系统代码示例:
```java
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
public class UserManagementSystem {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
List<User> users = new ArrayList<>();
int choice = 0;
do {
System.out.println("1. Add user");
System.out.println("2. View users");
System.out.println("3. Exit");
System.out.print("Enter your choice: ");
choice = scanner.nextInt();
switch (choice) {
case 1:
System.out.print("Enter name: ");
String name = scanner.next();
System.out.print("Enter email: ");
String email = scanner.next();
User user = new User(name, email);
users.add(user);
System.out.println("User added successfully!");
break;
case 2:
if (users.isEmpty()) {
System.out.println("No users found!");
} else {
for (User u : users) {
System.out.println(u);
}
}
break;
case 3:
System.out.println("Exiting...");
break;
default:
System.out.println("Invalid choice!");
}
} while (choice != 3);
scanner.close();
}
}
class User {
private String name;
private String email;
public User(String name, String email) {
this.name = name;
this.email = email;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
@Override
public String toString() {
return "User [name=" + name + ", email=" + email + "]";
}
}
```
以上代码使用了一个 `User` 类来表示用户,包括姓名和电子邮件地址。`UserManagementSystem` 类是主类,它允许用户添加新用户和查看所有用户。整个程序使用了一个简单的菜单系统。在菜单中选择退出时,程序将停止运行。
### 回答2:
Java用户管理系统是一种用于管理用户信息的程序。下面是示例代码:
```java
import java.util.ArrayList;
import java.util.Scanner;
class User {
private String username;
private String password;
public User(String username, String password) {
this.username = username;
this.password = password;
}
public String getUsername() {
return username;
}
public String getPassword() {
return password;
}
}
class UserManagementSystem {
private ArrayList<User> users;
public UserManagementSystem() {
users = new ArrayList<>();
}
public void addUser(String username, String password) {
User user = new User(username, password);
users.add(user);
}
public void removeUser(String username) {
for (User user : users) {
if (user.getUsername().equals(username)) {
users.remove(user);
break;
}
}
}
public boolean authenticateUser(String username, String password) {
for (User user : users) {
if (user.getUsername().equals(username) && user.getPassword().equals(password)) {
return true;
}
}
return false;
}
public ArrayList<User> getAllUsers() {
return users;
}
}
public class Main {
public static void main(String[] args) {
UserManagementSystem system = new UserManagementSystem();
Scanner scanner = new Scanner(System.in);
while (true) {
System.out.println("请输入指令:");
System.out.println("1 - 添加用户");
System.out.println("2 - 删除用户");
System.out.println("3 - 验证用户");
System.out.println("4 - 查看所有用户");
System.out.println("0 - 退出程序");
int command = scanner.nextInt();
scanner.nextLine();
if (command == 1) {
System.out.println("请输入用户名:");
String username = scanner.nextLine();
System.out.println("请输入密码:");
String password = scanner.nextLine();
system.addUser(username, password);
} else if (command == 2) {
System.out.println("请输入要删除的用户名:");
String username = scanner.nextLine();
system.removeUser(username);
} else if (command == 3) {
System.out.println("请输入用户名:");
String username = scanner.nextLine();
System.out.println("请输入密码:");
String password = scanner.nextLine();
boolean authenticated = system.authenticateUser(username, password);
if (authenticated) {
System.out.println("验证成功!");
} else {
System.out.println("验证失败!");
}
} else if (command == 4) {
ArrayList<User> users = system.getAllUsers();
for (User user : users) {
System.out.println("用户名:" + user.getUsername() + " 密码:" + user.getPassword());
}
} else if (command == 0) {
break;
} else {
System.out.println("无效的指令!");
}
}
scanner.close();
}
}
```
以上是一个简单的Java用户管理系统代码示例。该系统允许用户添加、删除、验证和查看所有用户。用户信息通过用户类进行封装,用户管理系统类负责管理所有用户。主程序使用一个循环来接收用户指令,并根据指令执行相应的操作。
### 回答3:
Java用户管理系统是一种用于管理用户信息的系统,可以实现用户的注册、登录、修改信息等功能。以下是一个简单的示例代码:
```java
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
public class UserManagementSystem {
private static List<User> users = new ArrayList<>();
public static void main(String[] args) {
while (true) {
System.out.println("欢迎使用用户管理系统!");
System.out.println("1. 注册新用户");
System.out.println("2. 用户登录");
System.out.println("3. 修改用户信息");
System.out.println("0. 退出系统");
System.out.print("请输入操作序号:");
Scanner scanner = new Scanner(System.in);
int choice = scanner.nextInt();
scanner.nextLine(); // 清空输入缓冲区
switch (choice) {
case 1:
registerUser();
break;
case 2:
loginUser();
break;
case 3:
modifyUserInfo();
break;
case 0:
System.out.println("感谢使用用户管理系统,再见!");
System.exit(0);
default:
System.out.println("无效的操作序号,请重新输入!");
break;
}
System.out.println();
}
}
private static void registerUser() {
Scanner scanner = new Scanner(System.in);
System.out.print("请输入用户名:");
String username = scanner.nextLine();
System.out.print("请输入密码:");
String password = scanner.nextLine();
User user = new User(username, password);
users.add(user);
System.out.println("用户注册成功!");
}
private static void loginUser() {
Scanner scanner = new Scanner(System.in);
System.out.print("请输入用户名:");
String username = scanner.nextLine();
System.out.print("请输入密码:");
String password = scanner.nextLine();
for (User user : users) {
if (user.getUsername().equals(username) && user.getPassword().equals(password)) {
System.out.println("用户登录成功!");
return;
}
}
System.out.println("用户名或密码错误!");
}
private static void modifyUserInfo() {
Scanner scanner = new Scanner(System.in);
System.out.print("请输入要修改信息的用户名:");
String username = scanner.nextLine();
for (User user : users) {
if (user.getUsername().equals(username)) {
System.out.print("请输入新的密码:");
String newPassword = scanner.nextLine();
user.setPassword(newPassword);
System.out.println("密码修改成功!");
return;
}
}
System.out.println("用户名不存在!");
}
}
class User {
private String username;
private String password;
public User(String username, String password) {
this.username = username;
this.password = password;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
```
以上是一个简单的Java用户管理系统代码,具备基本的注册、登录、修改密码等功能。用户可以根据提示进行相应的操作,并会根据输入做出相应的反馈。该系统使用了一个`User`类来表示用户信息,利用`List`集合保存了已注册的用户。
1.集合类的操作。模拟用户登录,实现对多个用户信息的操作。 【需求】:对用户类的操作,添加用户(注册功能)、查找用户(登录功能)、修改用户(重置密码)等 【思路】: 1. 定义用户类的JavaBean:User(用户名、密码、生日) 2. 定义接口: 用户操作接口(IUserDao) 包含添加用户(注册功能)、查找用户(登录功能)、用户(重置密码)三 种抽象方法 3. 定义实现接口类:UserDaoImpl, 重写三个抽象方法,其中的登录功能可以“模拟用户登录”实验来完成。 4. 在test包中,定义一个测试类(TestUser), (1)添加main方法,定义ArrayList集合对象,实现添加3个学生的信息并存储在集合对象里。 (2)ArrayList集合元素采用增强型for实现遍历。 List集合元素采用迭代器遍历 java语言编写
好的,以下是Java语言编写的完整代码实现:
User.java:
```java
public class User {
private String username;
private String password;
private String birthday;
public User(String username, String password, String birthday) {
this.username = username;
this.password = password;
this.birthday = birthday;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getBirthday() {
return birthday;
}
public void setBirthday(String birthday) {
this.birthday = birthday;
}
}
```
IUserDao.java:
```java
public interface IUserDao {
void addUser(User user);
User findUser(String username, String password);
void modifyPassword(String username, String newPassword);
}
```
UserDaoImpl.java:
```java
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class UserDaoImpl implements IUserDao {
private List<User> userList = new ArrayList<>();
@Override
public void addUser(User user) {
userList.add(user);
System.out.println("添加用户成功:" + user.getUsername());
}
@Override
public User findUser(String username, String password) {
for (User user : userList) {
if (user.getUsername().equals(username) && user.getPassword().equals(password)) {
System.out.println("登录成功:" + user.getUsername());
return user;
}
}
System.out.println("登录失败:用户名或密码错误!");
return null;
}
@Override
public void modifyPassword(String username, String newPassword) {
for (User user : userList) {
if (user.getUsername().equals(username)) {
user.setPassword(newPassword);
System.out.println("修改密码成功:" + user.getUsername());
return;
}
}
System.out.println("修改密码失败:用户不存在!");
}
public List<User> getUserList() {
return userList;
}
public void printUserList() {
System.out.println("使用增强型for循环遍历List集合:");
for (User user : userList) {
System.out.println(user.getUsername() + " " + user.getPassword() + " " + user.getBirthday());
}
System.out.println("-----------------------");
System.out.println("使用迭代器遍历List集合:");
Iterator<User> iterator = userList.iterator();
while (iterator.hasNext()) {
User user = iterator.next();
System.out.println(user.getUsername() + " " + user.getPassword() + " " + user.getBirthday());
}
}
}
```
TestUser.java:
```java
import java.util.ArrayList;
public class TestUser {
public static void main(String[] args) {
IUserDao userDao = new UserDaoImpl();
User user1 = new User("张三", "123456", "2000-01-01");
userDao.addUser(user1);
User user2 = new User("李四", "123456", "2000-02-02");
userDao.addUser(user2);
User user3 = new User("王五", "123456", "2000-03-03");
userDao.addUser(user3);
User loginUser = userDao.findUser("李四", "123456");
userDao.modifyPassword("李四", "654321");
userDao.printUserList();
}
}
```
以上就是使用Java语言实现模拟用户登录的集合类操作的完整代码。