error("新增用户'" + user.getUserName() + "'失败,登录账号已存在");怎么把新增用户替换成常量
时间: 2024-03-31 16:33:55 浏览: 17
您可以将新增用户替换成一个常量字符串,例如:
```java
private static final String ERROR_MSG = "新增用户失败,登录账号已存在";
...
throw new Exception(ERROR_MSG);
```
这样,当出现异常时,错误信息就会显示为常量字符串"新增用户失败,登录账号已存在"。
相关问题
请描述这段代码:try { // 验证是否存在这个用户 boolean userFlag = false; for (Map.Entry<Integer, UserOperateModel> entry : users.entrySet()) { if (entry.getValue().getUserName().equals(user.getUserName())) { userFlag = true; break; } } if (!userFlag) { Integer userId = users.size() + 1; user.setUserId(userId); users.put(userId, user); successNum++; successMsg.append("<br/>" + successNum + "、用户 " + user.getUserName() + " 导入成功"); } else if (isUpdateSupport) { users.put(user.getUserId(), user); successNum++; successMsg.append("<br/>" + successNum + "、用户 " + user.getUserName() + " 更新成功"); } else { failureNum++; failureMsg.append("<br/>" + failureNum + "、用户 " + user.getUserName() + " 已存在"); } }
这段代码是一个 try 块,主要用于导入用户数据。代码中的 for 循环遍历了一个名为 users 的 Map 集合,该集合的键值为 Integer 类型,值为 UserOperateModel 类型。在循环中,代码检查当前用户是否已经存在于 users 集合中。如果不存在,代码会将该用户添加到集合中,并将成功导入的用户数量 successNum 加 1。如果用户已经存在于集合中,代码会检查是否支持更新用户信息,如果支持则更新用户信息,并将 successNum 加 1。如果不支持更新用户信息,则将失败的用户数量 failureNum 加 1。最后,代码会根据操作结果,拼接成一个成功或失败的消息 successMsg 或 failureMsg,并将其返回。
将package shiyan3; public class Test { public static void main(String[] args) { try { Student student = new Student("Alice", "123456", "Computer Science"); System.out.println("Student name: " + student.getUsername()); System.out.println("Student password: " + student.getPassword()); System.out.println("Student major: " + student.getMajor()); Teacher teacher = new Teacher("Bob", "123456", "Mathematics"); System.out.println("Teacher name: " + teacher.getUsername()); System.out.println("Teacher password: " + teacher.getPassword()); System.out.println("Teacher department: " + teacher.getDepartment()); Admin admin = new Admin("Charlie", "123456", "Director"); System.out.println("Admin name: " + admin.getUsername()); System.out.println("Admin password: " + admin.getPassword()); System.out.println("Admin position: " + admin.getPosition()); } catch (Exception e) { System.out.println("An error occurred: " + e.getMessage()); } } }修改这段代码,使他有键盘输入的值
以下是修改后的代码,使用了Scanner类来获取键盘输入的值:
```java
package shiyan3;
import java.util.Scanner;
public class Test {
public static void main(String[] args) {
try {
Scanner scanner = new Scanner(System.in);
System.out.print("Enter student name: ");
String studentName = scanner.nextLine();
System.out.print("Enter student password: ");
String studentPassword = scanner.nextLine();
System.out.print("Enter student major: ");
String studentMajor = scanner.nextLine();
Student student = new Student(studentName, studentPassword, studentMajor);
System.out.println("Student name: " + student.getUsername());
System.out.println("Student password: " + student.getPassword());
System.out.println("Student major: " + student.getMajor());
System.out.print("\nEnter teacher name: ");
String teacherName = scanner.nextLine();
System.out.print("Enter teacher password: ");
String teacherPassword = scanner.nextLine();
System.out.print("Enter teacher department: ");
String teacherDepartment = scanner.nextLine();
Teacher teacher = new Teacher(teacherName, teacherPassword, teacherDepartment);
System.out.println("Teacher name: " + teacher.getUsername());
System.out.println("Teacher password: " + teacher.getPassword());
System.out.println("Teacher department: " + teacher.getDepartment());
System.out.print("\nEnter admin name: ");
String adminName = scanner.nextLine();
System.out.print("Enter admin password: ");
String adminPassword = scanner.nextLine();
System.out.print("Enter admin position: ");
String adminPosition = scanner.nextLine();
Admin admin = new Admin(adminName, adminPassword, adminPosition);
System.out.println("Admin name: " + admin.getUsername());
System.out.println("Admin password: " + admin.getPassword());
System.out.println("Admin position: " + admin.getPosition());
scanner.close();
} catch (Exception e) {
System.out.println("An error occurred: " + e.getMessage());
}
}
}
```
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