我要编写一个图书馆应用程序。
我使用 netbeans。
我有一个这样的界面:
package Library;
public interface UserInformation {
public void setFName(String fn);
public String getFName();
public void setLName(String ln);
public String getLName();
public void setRegNum(int reg_num);
public int getRegNum();
public void setDate(int reg_date);
public int getDate();
}
我的 NewUserDialog 实现了这个接口(interface):
private String FirstName="";
private String LastName="";
private int Registration_Number=0;
private int Date=0;
private String fileadress="AllUserRecords.txt";
public NewUserDialog(java.awt.Frame parent, boolean modal) {
super(parent, modal);
initComponents();
}
// // <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
jLabel4 = new javax.swing.JLabel();
jTextField1 = new javax.swing.JTextField();
jTextField2 = new javax.swing.JTextField();
jTextField3 = new javax.swing.JTextField();
jButton1 = new javax.swing.JButton();
jButton2 = new javax.swing.JButton();
jLabel5 = new javax.swing.JLabel();
jLabel6 = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);
jLabel1.setFont(new java.awt.Font("Tunga", 1, 14)); // NOI18N
jLabel1.setText("Add New User (Registration)");
jLabel2.setText("First Name:");
jLabel3.setText("Last Name:");
jLabel4.setText("Date:");
jTextField2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jTextField2ActionPerformed(evt);
}
});
jButton1.setText("Create");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jButton2.setText("Back");
jLabel5.setText("Registration Number is:");
jLabel6.setText(" ");
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(54, 54, 54)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel2)
.addComponent(jLabel4)
.addComponent(jLabel3)
.addComponent(jLabel5))
.addGap(98, 98, 98)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel6)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jTextField3)
.addComponent(jTextField1, javax.swing.GroupLayout.DEFAULT_SIZE, 81, Short.MAX_VALUE)
.addComponent(jButton2, javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jTextField2))
.addComponent(jLabel1)))
.addGroup(layout.createSequentialGroup()
.addGap(68, 68, 68)
.addComponent(jButton1)))
.addContainerGap(141, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel1)
.addGap(26, 26, 26)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel2)
.addGroup(layout.createSequentialGroup()
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(28, 28, 28)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel3))
.addGap(34, 34, 34)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jTextField3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel4))))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 50, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel5)
.addComponent(jLabel6))
.addGap(27, 27, 27)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton1)
.addComponent(jButton2))
.addGap(116, 116, 116))
);
pack();
}// </editor-fold>
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
try{
setFName(jTextField1.getText());
if(havedigit(FirstName)==true) throw new Exception();
WriteToFile(getFName());
setLName(jTextField2.getText());
if(havedigit(LastName)==true) throw new Exception();
WriteToFile(getLName());
setDate(Integer.parseInt(jTextField3.getText()));
WriteToFile(String.valueOf(getDate()));
Random rnd1=new Random();
Registration_Number=rnd1.nextInt(100);
setRegNum(Registration_Number);
WriteToFile(String.valueOf(getRegNum()));
jLabel6.setText(String.valueOf(getRegNum()));
}
catch(Exception e){
jLabel6.setText("Error!");
}
}
public boolean havedigit(String in){
for(int i=0;i<in.length();i++){
if(Character.isDigit(in.charAt(i))) return true;
}
return false;
}
public void WriteToFile(String content){
try{
File f=new File("C:\\userrecords.txt");
if(!f.exists()){
f.createNewFile();
}
else{
FileWriter fw=new FileWriter(f.getAbsoluteFile(), true);
BufferedWriter bw=new BufferedWriter(fw);
bw.write(content);
bw.newLine();
bw.close();
System.out.println("Done");
}
}
catch(Exception e){
e.printStackTrace();
}
}
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
NewUserDialog dialog = new NewUserDialog(new javax.swing.JFrame(), true);
dialog.addWindowListener(new java.awt.event.WindowAdapter() {
public void windowClosing(java.awt.event.WindowEvent e) {
System.exit(0);
}
});
dialog.setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JLabel jLabel5;
private javax.swing.JLabel jLabel6;
private javax.swing.JTextField jTextField1;
private javax.swing.JTextField jTextField2;
private javax.swing.JTextField jTextField3;
// End of variables declaration
public void setFName(String fn) {
FirstName.equals(fn);
}
public String getFName() {
return FirstName;
}
public void setLName(String ln) {
LastName.equals(ln);
}
public String getLName() {
return FirstName;
}
public void setRegNum(int reg_num) {
Registration_Number=reg_num;
}
public int getRegNum() {
return Registration_Number;
}
public void setDate(int reg_date) {
Date=reg_date;
}
public int getDate() {
return Date;
}
}
我的目的是当我们归档 jtextfile 字段并单击按钮时，此数据应保存到 .txt 文件中。 但是 Fname 和 Lname 都没有保存到文件，只有“Date”文件保存到文件。 我希望 Fname 和 Lname 以及数据必须定期存储在文本文件中。
谢谢!
最佳答案
您的设置方法 setFName(...) 和 setLName(...) 根本不做任何设置。相反，他们所做的只是执行不必要且莫名其妙的相等性测试，然后丢弃结果:
public void setLName(String ln) {
LastName.equals(ln); // ???????
}
如何创建真正的 setter 方法来设置引用变量持有的对象:
public void setLName(String ln) {
lastName = ln; // note variable names should begin w/ a lowercase letter
}
如果您不设置这些字段，那么您就不能指望来自 getter 方法的信息在写入文件时有用。
还有一个较弱的 catch block ，它不会通知您堆栈跟踪的内容，这些信息可能会帮助您找出问题所在。
此外，您的 GUI 实现一个似乎更适合模型类而非 View (GUI) 类的非 GUI 界面的目的是什么？我更喜欢这里的组合而不是继承。
关于java - 从 jtextfield 提供数据并将它们存储到文件中，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/13957688/