用户界面可以帮助我用这个类似的代码构造，但添加了需求（正确的日期格式，必须是18岁以上）Java GUI

Question

private void emailKeyReleased（java.awt.event.KeyEvent evt）{
布尔at=false； Boolean dotcom=false

    for(int x=1; x<=email.getText().length();x++){
    if(email.getText().substring(x-1,x).equals("@") && x>3){
        at=true;
      }
    else{
         elabel.setForeground(Color.red);
         elabel.setText("Bad Email");
    }
   
    if(x>5 && email.getText().substring(x-4,x).equals(".com") && x>3){
   dotcom=true;
      }
    else{
         elabel.setForeground(Color.red);
         elabel.setText("Bad Email");
    }
    if(at==true && dotcom==true){
        elabel.setForeground(Color.blue);
        elabel.setText("Good Email");
    }
    }

我希望我的代码在（mm/dd/yy）处显示消息对话框，标签为“不正确的日期格式”或“不是18”和“18+”

Answer 1

我创建了一个按bearth日期计算的chek years函数（使用Calendar类）。 当你运行main时，你应该输入你的停泊日期，如果你年龄大于或小于18岁，电脑会打印出来

import java.util.Calendar;
import java.util.Date;

import javax.swing.JOptionPane;

public class Main{
    public static void main(String[] args) {
        Calendar c = Calendar.getInstance();
        c.set(Calendar.YEAR, Integer.parseInt(JOptionPane.showInputDialog("Enter Year:")));
        c.set(Calendar.MONTH, Integer.parseInt(JOptionPane.showInputDialog("Enter Month:")) - 1);
        c.set(Calendar.DAY_OF_MONTH, Integer.parseInt(JOptionPane.showInputDialog("Enter Day:")));
        JOptionPane.showMessageDialog(null, 
                "Your date of bearth is " + 
        c.get(Calendar.DAY_OF_MONTH) + "\\" + (c.get(Calendar.MONTH) + 1) + "\\" + c.get(Calendar.YEAR));
        if (validate(c, 18)) {
            System.out.println("you\'re older then 18");
        }else {
            System.out.println("you\'re younger then 18");
        }
    }
    public static boolean validate(Calendar bearth, int yearsDiff) {
        Calendar today = Calendar.getInstance();
        if (today.get(Calendar.YEAR) - yearsDiff > bearth.get(Calendar.YEAR)) {
            return true;
        }
        if (today.get(Calendar.YEAR) - yearsDiff < bearth.get(Calendar.YEAR)) {
            return false;
        }
        if (today.get(Calendar.DAY_OF_YEAR) >= bearth.get(Calendar.DAY_OF_YEAR)) {
            return true;
        }
        return false;
    }
}