java - 文本文件到 jlabel 以及 jlabel 与文本文件的比较

Question

所以我正在制作一个关于 ATM 系统的 GUI我想要做的是，当客户输入他/她的帐号并固定时，程序将在 DATABASE.txt 中搜索它，当它与 DATABASE.txt 中的信息匹配时。程序将自动显示名称、帐号、年龄、性别和平衡。但就我而言，我收到此错误，但我不知道如何修复它。请帮助我。如果你帮助我，我将不胜感激:)谢谢你，干杯:)。附:我希望你们能理解我的源代码T^T。

一级

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;

public class Xavier1 extends JFrame implements ActionListener,Runnable
{
JButton a[] = new JButton [10];
JLabel pin,acc;
JTextField acc1;
JButton del,ok,crt;
int c=0,d=0,e=0;
JPasswordField pin1;
JFrame x;
String us,pw;

public void run()
{

}

public Xavier1()
{
    x = new JFrame("ATM");
    x.setLayout(null);
    x.setBounds(400,100,550,500);
    x.setVisible(true);

    JPanel x3 = new JPanel();
    x.add(x3);
    x3.setVisible(true);
    x3.setBounds(150,420,250,100);
    crt = new JButton("Create Account");
    crt.addActionListener(this);
    x3.add(crt);

    JPanel x2 = new JPanel();
    x.add(x2);
    x2.setBounds(150,10,250,100);
    x2.setVisible(true);
    x2.setLayout(new GridLayout(4,2));
    pin = new JLabel("PIN");
    acc = new JLabel("ACCOUNT NUMBER");
    pin1 = new JPasswordField(20);
    acc1 = new JTextField(20);

    x2.add(acc);
    x2.add(acc1);
    x2.add(pin);
    x2.add(pin1);


    JPanel x1 = new JPanel();
    x.add(x1);
    x1.setBounds(150,200,250,200);
    x1.setVisible(true);
    x1.setLayout(new GridLayout(4,3));

    for(int b=0;b<10;b++)
    {
        a[b] = new JButton();
        a[b].setText(Integer.toString(b));
        x1.add(a[b]);
        a[b].addActionListener(this);
    }
    ok = new JButton("OK");
    ok.addActionListener(this);
    del = new JButton("DEL");
    del.addActionListener(this);
    x1.add(ok);
    x1.add(del);




}
public static void main (String args[])
{
    Xavier1 xs = new Xavier1();
    Thread xd = new Thread(xs);
    xd.setDaemon(true);



}
public void actionPerformed(ActionEvent z)
{
    Object zz = z.getSource();

    if(e == 0)
    {
        for(int c=0;c<a.length;c++)
        {
            if(zz == a[c])
            {
            acc1.setText(acc1.getText()+a[c].getText());
            }

        }
    }
    if(zz == ok)
    {
        e++;
    }
    if(e==2)
    {
        GateKeeper();


    }
    if(e == 1)
    {
        for(int d=0;d<a.length;d++)
        {
            if(zz == a[d])
            {
            pin1.setText(pin1.getText()+a[d].getText());
            }

        }

    }
    if(zz == crt)
    {
        Reg rs = new Reg();
        Thread sr = new Thread(rs);
        sr.start();
        x.setVisible(false);
    }
    if(zz == del)
    {
        if(e == 0)
        {
            acc1.setText(null);
        }
        if(e == 1)
        {
            pin1.setText(null);
        }
    }

}
public void GateKeeper()
{
    try
    {
        Scanner sc = new Scanner(new File("DATABASE.txt"));
        int loop = sc.nextInt();
        sc.nextLine();
        for(int gk=0;gk<loop;gk++)
        {
            String ps[] = sc.nextLine().split(" ");
            us = ps[0];
            pw = ps[1];
            if(acc1.getText().equals(us));
            {
                if(pin1.getText().equals(pw))
                {
                    Bank b = new Bank();
                    Thread xb = new Thread(b);
                    xb.start();
                    x.setVisible(false);

                }
            }

        }
    }
    catch(FileNotFoundException s)
    {

    }
}
}

二等

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;

public class Reg extends Bank
{
JButton res,back,next;
JFrame r;

public Reg()
{
    r = new JFrame("REGISTRATION");
    r.setVisible(true);
    x.setVisible(false);
    r.setBounds(400,100,550,500);
    r.setLayout(null);
    X.setVisible(false);

    n = new JLabel("Name");
    age = new JLabel("AGE");
    sex = new JLabel("SEX");
    dep = new JLabel("DEPOSIT");
    accn = new JLabel("ACCOUNT NUMBER");
    pins = new JLabel("PIN");
    n1 = new JTextField(20);
    accn1 = new JTextField(20);
    bal1 = new JTextField(20);
    sex1 = new JTextField(20);
    age1 = new JTextField(20);
    dep1 = new JTextField(20);
    pins1 = new JPasswordField(20);

    JPanel r1 = new JPanel();
    r.add(r1);
    r1.setVisible(true);
    r1.setBounds(50,10,400,400);

    r1.setLayout(new GridLayout(7,2));

    r1.add(accn);
    r1.add(accn1);
    r1.add(pins);
    r1.add(pins1);
    r1.add(n);
    r1.add(n1);
    r1.add(age);
    r1.add(age1);
    r1.add(sex);
    r1.add(sex1);
    r1.add(dep);
    r1.add(dep1);

    JPanel r2 = new JPanel();
    r.add(r2);
    r2.setVisible(true);
    r2.setBounds(130,400,300,50);
    r2.setLayout(new GridLayout(0,3));
    back = new JButton("BACK");
    next = new JButton("NEXT");
    res = new JButton("REGISTER!");
    res.addActionListener(this);
    back.addActionListener(this);
    next.addActionListener(this);
    r2.add(back);
    r2.add(res);
    r2.add(next);

}
public void DATABASE()
{
    try
    {

    FileWriter fw = new FileWriter("DATABASE.txt",true);
    PrintWriter pw = new PrintWriter(fw);

    pw.print(accn1.getText()+" ");
    pw.print(pins1.getText()+" ");
    pw.print(n1.getText()+" ");
    pw.print(age1.getText()+" ");
    pw.print(sex1.getText()+" ");
    pw.print(dep1.getText()+" ");
    pw.println();
    pw.close();


    }
    catch(IOException s)
    {

    }
}
public static void main(String args[])
{


}
public void actionPerformed(ActionEvent rg)
{
    Object rz = rg.getSource();

    if(rz == res)
    {
        DATABASE();
    }
    if(rz == next)
    {
        Bank b = new Bank();
        Thread xb = new Thread(b);
        xb.start();
        r.setVisible(false);
    }
    if(rz == back)
    {
        Xavier1 xs = new Xavier1();
        Thread xd = new Thread(xs);
        xd.start();
        r.setVisible(false);
    }

}
}

三级

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;

public class Bank extends Xavier1
{


JLabel n,accn,bal,age,sex,dep,pins;
JFrame X,r;
JTextField n1,accn1,bal1,sex1,age1,dep1;
JPasswordField pins1;
JLabel Xn,Xacc,Xbal,Xage,Xsex;
String xn,xacc,xbal,xage,xsex;

public void reader()
{
    try
    {
    FileReader fr = new FileReader("DATABASE.TXT");
    BufferedReader br = new BufferedReader(fr);
    }
    catch(FileNotFoundException s)
    {

    }
}


public Bank()
{
    X = new JFrame("BANK");
    X.setVisible(true);
    X.setBounds(400,100,550,500);
    X.setLayout(null);
    x.setVisible(false);


    JPanel info = new JPanel();
    X.add(info);
    info.setVisible(true);
    info.setBounds(50,10,400,400);
    info.setLayout(new GridLayout(7,2));

    try
    {
        Scanner s2 = new Scanner(new File("DATABASE.txt"));
        int loop2 = s2.nextInt();
        for(int gkz=0;gkz<loop2;gkz++)
        {
            String info2[]= s2.nextLine().split(" ");
            xn   = info2[2];
            xacc = info2[0];
            xage = info2[3];
            xsex = info2[4];
            xbal =info2[5];

            if(acc1.getText().equals(us))
            {
                if(pin1.getText().equals(pw))
                {
                    JLabel Xn= new JLabel("NAME: "+xn);
                    JLabel Xacc = new JLabel("ACCOUNT NUMBER: "+xacc);
                    JLabel Xage = new JLabel("AGE: "+xage);
                    JLabel Xsex = new JLabel("SEX: "+sex);
                    JLabel Xbal = new JLabel("BALANCE: "+xbal);

                }
            }


        }
    }
    catch(FileNotFoundException s)
    {

    }





}
public static void main(String args[])
{


}
public void actionPerformed(ActionEvent z1)
{
    Object z2 = z1.getSource();
}

}

这是我遇到的错误

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 2
at Bank.<init>(Bank.java:54)
at Xavier1.GateKeeper(Xavier1.java:160)
at Xavier1.actionPerformed(Xavier1.java:108)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:708)
at java.awt.EventQueue$4.run(EventQueue.java:706)
at java.security.AccessController.doPrivileged(Native Method)
at     java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

Answer 1

java.lang.ArrayIndexOutOfBoundsException: 2 (Bank.java:54)

(Bank.java:54) - xn = info2[2];

这就是你的问题。假设你的文件是这样的

3
data data data data
data data data data

下面代码中的第一行将读取 3，但扫描仪将停留在该行。

int loop2 = s2.nextInt();  
for(int gkz=0;gkz<loop2;gkz++)
{
    String info2[]= s2.nextLine().split(" ");

因此，对 nextLine() 的下一次调用将仅消耗换行符，并且只会带您到下一行，但实际上不会读取 它。所以实际上 s2.nextLine().split(""); 将返回一个空数组。因此，当您尝试执行 info[2] 时，您会收到 ArrayIndexOutOfBoundsException 因为索引 2 不存在。

两个可能的修复。

1. 只需在 int loop2 = s2.nextInt(); 之后调用 s2.nextLine() 即可

2. 就我个人而言，我更喜欢总是按行读取(而不是 nextInt/nextDouble)并解析它，这样我就不会遇到您遇到的问题。

   int loop2 = Integer.parseInt(s2.nextLine().trim());    
   for(int gkz=0;gkz<loop2;gkz++) {
       ...