Question

我在使用JAVA（新手）中的电子邮件验证时遇到问题，不断收到这些错误，并对原因感到困惑。我应该让这些人发电子邮件，检查它的设定标准（由我的教授），然后获得有关测试的信息。当我检查电子邮件时，我应该显示错误，如果有的话。

错误

N:\Programming\Java\Homework\EmailAndGrade.java:29: illegal start of expression
    private static boolean validEmail(sEmail);
    ^
N:\Programming\Java\Homework\EmailAndGrade.java:29: illegal start of expression
    private static boolean validEmail(sEmail);
            ^
N:\Programming\Java\Homework\EmailAndGrade.java:29: ';' expected
    private static boolean validEmail(sEmail);
                  ^
3 errors

代码

public class EmailAndGrade
{

    public static void main(String[] args)
    {
        //Variables
        String sEmail, sError, sTest;
        int iTest;
        char cGrade;

        sEmail = JOptionPane.showInputDialog("Enter your email: ");


        private static boolean validEmail(sEmail);
                {
                // editing to make requirements listed
                // return email.matches("[A-Z0-9._%+-]+@[A-Z0-9.-]+\\.[A-Z]{2,4}");
                return email.matches("[A-Z0-9]{7}+@[springfieldcollege]+\\.[edu]");
                };

        sError = "One or More Errors with the Input Email.\n" +
                 "Email is Empty.\n" +
                 "Email must be less than 30 characters.\n" +
                 "Must end in: @springfieldcollege.edu.\n" +
                 "Can only have one @.\n" +
                 "Must start with A through Z or a through z.\n" +
                 "Can not have: # $ % & ,\n ";

        sTest = JOptionPane.showInptDialog("Enter Test Grade: ");

        iTest = Integer.parseInt(sTest);

        System.exit(0);


    }

    /*
        void checkEmails()
        {
            for(String email : emailAddresses) {
            if(validEmail(email)) {
                 // it's a good email - do something good with it

            }
            else {
                 // it's a bad email - do something... bad to it? sounds dirty...
                JOptionPane.showMessageDialog(null,
                                              sError,
                                              "Email Error - Killian O'Brien",
                                              JOptionPane.INFORMATION_MESSAGE);
                }
    }*/



}

*编辑

好的，现在我有了这段代码

package com.mkyong.regex;

import javax.swing.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class EmailAndGrade
{

public static void main(String[] args)
{
    //Variables
    String sEmail, sError, sTest;
    int iTest;
    char cGrade;

    sEmail = JOptionPane.showInputDialog("Enter your email: ");


    sError = "One or More Errors with the Input Email.\n" +
             "Email is Empty.\n" +
             "Email must be less than 30 characters.\n" +
             "Must end in: @springfieldcollege.edu.\n" +
             "Can only have one @.\n" +
             "Must start with A through Z or a through z.\n" +
             "Can not have: # $ % & ,\n ";

    sTest = JOptionPane.showInptDialog("Enter Test Grade: ");

    iTest = Integer.parseInt(sTest);

    System.exit(0);


}

public static boolean validEmail(String sEmail){
        return email.matches("[A-Z0-9]{7}+@[springfieldcollege]+\\.[edu]");
    }

public static void checkEmails(){
    for(String sEemail : emailAddresses) {
        if(validEmail(email)) {
            // it's a good email - do something good with it
        }
        else {
            // it's a bad email - do something... bad to it? sounds dirty...
            JOptionPane.showMessageDialog(null,
                                          sError,
                                          "Email Error - Killian O'Brien",
                                          JOptionPane.INFORMATION_MESSAGE);
                 }
             }
             }
}

我现在正在接受这些

N:\Programming\Java\Homework\EmailAndGrade.java:37: cannot find symbol
symbol  : method showInptDialog(java.lang.String)
location: class javax.swing.JOptionPane
        sTest = JOptionPane.showInptDialog("Enter Test Grade: ");
                           ^
N:\Programming\Java\Homework\EmailAndGrade.java:47: cannot find symbol
symbol  : variable emailAddresses
location: class com.mkyong.regex.EmailAndGrade
        for(String email : emailAddresses) {
                           ^
N:\Programming\Java\Homework\EmailAndGrade.java:54: cannot find symbol
symbol  : variable sError
location: class com.mkyong.regex.EmailAndGrade
                                              sError,
                                              ^
N:\Programming\Java\Homework\EmailAndGrade.java:63: cannot find symbol
symbol  : variable email
location: class com.mkyong.regex.EmailAndGrade
        return email.matches("[A-Z0-9]{7}+@[springfieldcollege]+\\.[edu]");
               ^
4 errors

当我输入这个时，我意识到我只有一堆未声明的变量。这是对的吗？

Answer 1

您正在其他方法 validEmail中实施方法main，这是不允许的。将您的方法移出main函数（在最后一行之前（在关闭大括号}之前））。 您还在方法实现中的两个位置使用了额外的分号（第一行结束和最后一行结束）。删除分号;。最后在方法签名中添加参数类型类（String）。更新后的方法应如下所示：

private static boolean validEmail(String sEmail){ // editing to make requirements listed // return email.matches("[A-Z0-9._%+-]+@[A-Z0-9.-]+\\.[A-Z]{2,4}"); return email.matches("[A-Z0-9]{7}+@[springfieldcollege]+\\.[edu]"); }

Answer 2

您不能内联声明函数。将validEmail()的声明移到main()之外。也应该从方法声明的末尾删除分号。

Java电子邮件验证中的编译器错误

2 个答案: