如何在文本文件中加一个？ （JAVA）

Question

我是一名Java新手，我正在尝试使用＆＃34;来测试生成唯一代码。 loop.Start从1000开始，它将继续添加一个，文本将存储在名为database.txt的文本文件中。例如，如果第一个用户使用该程序，它将存储＆＃34; 1001＆＃34;，然后第二个用户＆＃34; 1002＆＃34;，第三个将是＆＃34; 1003＆＃34; ...问题是我在for循环语句中遇到错误＆＃34;非法启动类型＆＃34;。请帮帮我，谢谢！

package car.park.auto.pay.system;
import java.io.*;
import java.lang.*;
import java.util.*;
import javax.swing.JOptionPane;
import javax.swing.JTextField;

public class SelectTimeAndDate extends javax.swing.JFrame {

public SelectTimeAndDate() {
    initComponents();

}

@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    jPanel1 = new javax.swing.JPanel();
    jLabel1 = new javax.swing.JLabel();
    jLabel2 = new javax.swing.JLabel();
    jLabel3 = new javax.swing.JLabel();
    confirmBut = new javax.swing.JButton();
    cancelBut1 = new javax.swing.JButton();
    hourField = new javax.swing.JTextField();
    dateField = new javax.swing.JTextField();
    minuteField = new javax.swing.JTextField();
    hourLab = new javax.swing.JLabel();
    dateLab = new javax.swing.JLabel();
    minuteLab = new javax.swing.JLabel();
    monthLab = new javax.swing.JLabel();
    monthField = new javax.swing.JTextField();
    secondLab = new javax.swing.JLabel();
    secondField = new javax.swing.JTextField();
    yearField = new javax.swing.JTextField();
    yearLab = new javax.swing.JLabel();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
    setTitle("Roy's Car Parking Auto Pay Station System");

    jLabel1.setText("Please input time and date that you are entering:");

    jLabel2.setText("Input time (hh:mm:ss):");
    jLabel2.setCursor(new java.awt.Cursor(java.awt.Cursor.DEFAULT_CURSOR));

    jLabel3.setText("Input date (dd/mm/yy):");

    confirmBut.setText("Confirm");
    confirmBut.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            confirmButActionPerformed(evt);
        }
    });

    cancelBut1.setText("Cancel");
    cancelBut1.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            cancelBut1ActionPerformed(evt);
        }
    });

    hourField.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            hourFieldActionPerformed(evt);
        }
    });

    hourLab.setText("Hour:");

    dateLab.setText("Date:");

    minuteLab.setText("Minute:");

    monthLab.setText("Month:");

    secondLab.setText("Second:");

    yearLab.setText("Year:");

    javax.swing.GroupLayout jPanel1Layout = new     javax.swing.GroupLayout(jPanel1);
    jPanel1.setLayout(jPanel1Layout);
    jPanel1Layout.setHorizontalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(jPanel1Layout.createSequentialGroup()
            .addGap(87, 87, 87)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                        .addComponent(jLabel2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addComponent(jLabel3, javax.swing.GroupLayout.DEFAULT_SIZE, 128, Short.MAX_VALUE))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addComponent(dateLab)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(dateField))
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addComponent(hourLab)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(hourField, javax.swing.GroupLayout.PREFERRED_SIZE, 34, javax.swing.GroupLayout.PREFERRED_SIZE))))
                .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                    .addComponent(confirmBut, javax.swing.GroupLayout.PREFERRED_SIZE, 103, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGap(22, 22, 22)))
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addComponent(minuteLab)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(minuteField, javax.swing.GroupLayout.PREFERRED_SIZE, 37, javax.swing.GroupLayout.PREFERRED_SIZE))
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addComponent(monthLab)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(monthField)))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addComponent(secondLab)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(secondField, javax.swing.GroupLayout.PREFERRED_SIZE, 37, javax.swing.GroupLayout.PREFERRED_SIZE))
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addGap(14, 14, 14)
                            .addComponent(yearLab)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(yearField, javax.swing.GroupLayout.PREFERRED_SIZE, 39, javax.swing.GroupLayout.PREFERRED_SIZE))))
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGap(13, 13, 13)
                    .addComponent(cancelBut1, javax.swing.GroupLayout.PREFERRED_SIZE, 103, javax.swing.GroupLayout.PREFERRED_SIZE)))
            .addContainerGap(56, Short.MAX_VALUE))
        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
            .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
            .addComponent(jLabel1)
            .addGap(121, 121, 121))
    );
    jPanel1Layout.setVerticalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
            .addContainerGap(35, Short.MAX_VALUE)
            .addComponent(jLabel1)
            .addGap(18, 18, 18)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(jLabel2)
                        .addComponent(hourField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(minuteField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(hourLab)
                        .addComponent(minuteLab))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(jLabel3)
                        .addComponent(dateField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(dateLab)
                        .addComponent(monthField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(monthLab)))
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(secondField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(secondLab))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(yearField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(yearLab))))
            .addGap(18, 18, 18)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addComponent(confirmBut, javax.swing.GroupLayout.PREFERRED_SIZE, 37, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addComponent(cancelBut1, javax.swing.GroupLayout.PREFERRED_SIZE, 37, javax.swing.GroupLayout.PREFERRED_SIZE))
            .addGap(28, 28, 28))
    );

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
            .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addGap(40, 40, 40))
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addGap(35, 35, 35)
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addContainerGap(69, Short.MAX_VALUE))
    );

    pack();
}// </editor-fold>                        

private void hourFieldActionPerformed(java.awt.event.ActionEvent evt) {                                          

}                                         

private void cancelBut1ActionPerformed(java.awt.event.ActionEvent evt) {                                           
    new Menu().setVisible(true);
    this.dispose();
}                                          

private void confirmButActionPerformed(java.awt.event.ActionEvent evt) {                                           
    String hour=hourField.getText();
    String minute=minuteField.getText();
    String second=secondField.getText();
    String date=dateField.getText();
    String month=monthField.getText();
    String year=yearField.getText();
    int i=1000;
    i=i+1;
    for(i<9000;i+){}

try{
FileWriter fw= new FileWriter("database.txt",true);

PrintWriter pw= new PrintWriter(fw);
pw.format("%s  %s  %s  %s  %s  %s  %s\r\n",hour,minute,second,date,month,year,i);

pw.close();

}
catch(IOException e){
    System.out.println("Error");
}


        if(hour.isEmpty()||minute.isEmpty()||second.isEmpty()||date.isEmpty()||month.isEmpty()||year.isEmpty()){
        JOptionPane.showMessageDialog(this,String.format("Please input all the details!", JOptionPane.ERROR_MESSAGE));
    }else{
        NewCode.getObj().setVisible(true);
        this.dispose();
    }

    }                                          




// Variables declaration - do not modify                     
private javax.swing.JButton cancelBut1;
private javax.swing.JButton confirmBut;
private javax.swing.JTextField dateField;
private javax.swing.JLabel dateLab;
private javax.swing.JTextField hourField;
private javax.swing.JLabel hourLab;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JPanel jPanel1;
private javax.swing.JTextField minuteField;
private javax.swing.JLabel minuteLab;
private javax.swing.JTextField monthField;
private javax.swing.JLabel monthLab;
private javax.swing.JTextField secondField;
private javax.swing.JLabel secondLab;
private javax.swing.JTextField yearField;
private javax.swing.JLabel yearLab;
// End of variables declaration                   
}

Answer 1

for(i<9000;i+){}

在语法上是错误的。它应该是：

for(;i<9000;i++){}