异常处理练习：用户名重复异常_java用户名或邮箱重复,请重新填写!-优快云博客

本文链接：https://blog.youkuaiyun.com/jspcnfc/article/details/103351314

这篇博客通过Java编程模拟注册过程中的用户名重复异常。文章详细介绍了如何定义用户类，并在主方法中实现检查和处理该异常，最终展示运行结果。

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要求：模拟注册操作，若用户名重复，则抛出异常“用户名重复”。

定义一个用户类

package DemoException;

public class Users {
    private String usersName;
    private int usersAge;

    public String getUsersName() {
        return usersName;
    }

    public int getUsersAge() {
        return usersAge;
    }

    public void setUsersName(String usersName) {
        this.usersName = usersName;
    }

    public void setUsersAge(int usersAge) {
        this.usersAge = usersAge;
    }

    public Users() {
    }

    public Users(String usersName, int usersAge) {
        this.usersName = usersName;
        this.usersAge = usersAge;
    }
}

主方法

package DemoException;

import java.util.ArrayList;

public class DemoException {
    public static void main(String[] args) {
        ArrayList<Users> usersList = new ArrayList<Users>();
        usersList.add(new Users("张三", 12));
        usersList.add(new Users("李四", 13));
        Users newUsers = new Users("张三", 12);
        try {
            for (Users i : usersList) {
                if (newUsers.getUsersName() == i.getUsersName()) {
                    throw new SeamUsersNameException("用户名重复");

                }
            }
            usersList.add(newUsers);
        } catch (SeamUsersNameException e) {
            System.out.println(e);//也可用e.printStackTrace();
        }

        for (Users i : usersList) {
            System.out.println("Users name is " + i.getUsersName() + ",Whose age is " + i.getUsersAge());
        }
    }
}
//异常类
class SeamUsersNameException extends RuntimeException {
    public SeamUsersNameException(String message) {
        super(message);
    }

    public SeamUsersNameException() {
    }
}

结果

DemoException.SeamUsersNameException: 用户名重复
Users name is 张三,Whose age is 12
Users name is 李四,Whose age is 13