java - 在电子邮件应用程序 Java 中找不到主类

Question

Error: Unable to load main class emailapp.Emailapp in module projects

java.lang.NoClassDefFoundError:emailapp/EmailApp(错误名称:emailapp/Emailapp)无法找到Java类请帮助我尝试用Java制作电子邮件应用程序 因此，有两个文件，一个用于主文件，一个用于类，因此每次我运行主文件时，它都不起作用，并显示我遇到麻烦的错误我尝试了 youtube 周围的类路径的解决方案，但即使对于环境变量仍然出现此错误

import java.util.Scanner;


public class Email {
    private String firstName;
    private String lastName;
    private String password;
    private String department;
    private int mailboxCapacity;
    private String alternateEmail;


    // Constructor to recieve first name and last name
    public Email(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
        System.out.println("EMAIL CREATED:" + this.firstName + " " +this.lastName);
        // Call a method that is asking for the department and return
        this.department = setDepartment();
    }
    // Ask the Department
    private String setDepartment() {
        System.out.print("Enter the department\n1 for Sales\n2 for Development\n3 for Accounting\n0 for none");
        Scanner in = new Scanner(System.in);
        int depChoice = in.nextInt();
        if (depChoice == 1) {return "sales";}
        else if (depChoice == 2) {return "dev";}
        else if (depChoice == 3) {return "acct";}
        else {return "";}
    }


    // Generate a random password

    // Set the mailbox capacity

    // Set the alternate email

    // Change the password
}

第二个文件

package emailapp;

public class EmailApp {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Email eml = new Email("John","Carl");
    }

}

请帮忙

Answer 1

你如何运行你的Main？命令行还是 IDE？假设您在 IDE 中运行它，您应该首先尝试clean rebuild您的项目。而且代码看起来很奇怪，最好重构为

 public static void main(String[] args) {
        System.out.print("Enter the department\n1 for Sales\n2 for Development\n3 for Accounting\n0 for none");
        Scanner in = new Scanner(System.in);
        int depChoice = in.nextInt();
        String department = "";
        if (depChoice == 1) department = "sales";
        else if (depChoice == 2)  department = return "dev";
        else if (depChoice == 3)  department = return "acct";
        Email eml = new Email("John","Carl", department);
    }