Question

我创建了一个程序的输出，允许用户输入他们的员工姓名和号码，然后输入他们的小时工资以及他们的正常工时和加班时间总数。这是我第一次在java中使用这种类型的程序，我遇到了Try-Catch块的问题，它从用户那里获取文本输入然后设置它。如果有人可以帮助我，我将不胜感激。

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

public class CreatePayrollFile extends JFrame implements ActionListener, WindowListener {
    public static final int WIDTH = 400;
    public static final int HEIGHT = 300;
    JPanel titlePanel = new JPanel();
    JPanel displayPanel = new JPanel(new GridLayout(6, 1));
    JPanel dPanel1 = new JPanel(new FlowLayout(FlowLayout.LEFT));
    JPanel dPanel2 = new JPanel(new FlowLayout(FlowLayout.LEFT));
    JPanel dPanel3 = new JPanel(new FlowLayout(FlowLayout.LEFT));
    JPanel dPanel4 = new JPanel(new FlowLayout(FlowLayout.LEFT));
    JPanel dPanel5 = new JPanel(new FlowLayout(FlowLayout.LEFT));
    JPanel dPanel6 = new JPanel(new FlowLayout(FlowLayout.LEFT));
    JPanel dPanel7 = new JPanel(new FlowLayout(FlowLayout.LEFT));
    JPanel buttonPanel = new JPanel();
    private JLabel companyName = new JLabel("Payroll INC.");
    Font bigFont = new Font("Helvetica", Font.ITALIC, 24);
    private JLabel prompt = new JLabel("Enter Payroll Information");
    private JTextField employeeName = new JTextField(10);
    private JTextField employeeNumber = new JTextField(10);
    private JTextField hourlyRate = new JTextField(10);
    private JTextField regularHours = new JTextField(10);
    private JTextField overtimeHours = new JTextField(10);
    private JLabel enameLabel = new JLabel("Employee Name       ");
    private JLabel enumLabel = new JLabel("Employee Number   ");
    private JLabel hrLabel = new JLabel("Hourly Rate                ");
    private JLabel rhLabel = new JLabel("Regular Hours          ");
    private JLabel orLabel = new JLabel("Overtime Hours        ");
    private JButton enterDataButton = new JButton("  Enter data  ");
    DataOutputStream ostream;

    public CreatePayrollFile() {
        super("Create Payroll File - Assignment 10");

        setSize(WIDTH, HEIGHT);
        try {
            ostream = new DataOutputStream(new FileOutputStream("payroll.dat"));
        } catch (IOException e) {
            System.err.println("File not opened");
            System.exit(1);
        }
        Container contentPane = getContentPane();
        contentPane.setLayout(new BorderLayout());

        companyName.setFont(bigFont);
        titlePanel.add(companyName);
        titlePanel.setBackground(Color.white);

        dPanel1.add(prompt);
        displayPanel.add(dPanel1);

        dPanel2.add(enameLabel);
        dPanel2.add(employeeName);
        displayPanel.add(dPanel2);

        dPanel3.add(enumLabel);
        dPanel3.add(employeeNumber);
        displayPanel.add(dPanel3);

        dPanel4.add(hrLabel);
        dPanel4.add(hourlyRate);
        displayPanel.add(dPanel4);

        dPanel5.add(rhLabel);
        dPanel5.add(regularHours);
        displayPanel.add(dPanel5);

        dPanel6.add(orLabel);
        dPanel6.add(overtimeHours);
        displayPanel.add(dPanel6);

        buttonPanel.setBackground(Color.white);
        buttonPanel.setLayout(new FlowLayout());
        enterDataButton.setMnemonic(KeyEvent.VK_E);
        buttonPanel.add(enterDataButton);
        enterDataButton.addActionListener(this);

        contentPane.add(titlePanel, BorderLayout.NORTH);
        contentPane.add(displayPanel, BorderLayout.CENTER);
        contentPane.add(buttonPanel, BorderLayout.SOUTH);
        addWindowListener(this);
    }

    private void writeRecord() {

        String employeeName;
        Double hourlyRate;
        Integer employeeNumber, regularHours, overtimeHours;


     // this is where I am having errors. It is saying that the getText method is undefined
     // for each respective use (int, string, double). I am also getting error "The method
     // writeString(String) is undefined for the type DataOutputStream" and the same 
     // undefined errors for the setText for each respective use. 

        try {
            employeeName = String.parseString(employeeName.getText());
            employeeNumber = Integer.parseInt(employeeNumber.getText());
            hourlyRate = Double.parseDouble(hourlyRate.getText());
            regularHours = Integer.parseInt(regularHours.getText());
            overtimeHours = Integer.parseInt(overtimeHours.getText());
            ostream.writeString(employeeName);
            ostream.writeInt(employeeNumber);
            ostream.writeDouble(hourlyRate);
            ostream.writeInt(regularHours);
            ostream.writeInt(overtimeHours);
            employeeName.setText("");
            employeeNumber.setText("");
            hourlyRate.setText("");
            regularHours.setText("");
            overtimeHours.setText("");

        } catch (NumberFormatException e2) {
            System.err.println("Invalid number ");
        } catch (IOException e3) {
            System.err.println("Error writing file");
            System.exit(1);
        }
    }

    public void actionPerformed(ActionEvent e) {
        writeRecord();
    }

    public void windowClosing(WindowEvent e) {
        try {
            ostream.close();
        } catch (IOException e4) {
            System.err.println("File not closed");
            System.exit(1);
        }

        System.exit(0);
    }

    public void windowClosed(WindowEvent e) {
    }

    public void windowDeiconified(WindowEvent e) {
    }

    public void windowIconified(WindowEvent e) {
    }

    public void windowOpened(WindowEvent e) {
    }

    public void windowActivated(WindowEvent e) {
    }

    public void windowDeactivated(WindowEvent e) {
    }

    public static void main(String[] args) {
        CreatePayrollFile cmof = new CreatePayrollFile();
        cmof.setVisible(true);
    }
}

因为我之前已经在这个论坛上发布了家庭作业协助请求，所以我提前说明我知道这是家庭作业，但正如任何人都能看到的那样，我不只是要求人们去做它。我觉得不得不说这是修辞，但我不想让任何人认为我没有付出努力。我已经投入并完成了教师教授的所有形式的所有内容，但是当他参加讲座的部分内容并获得方法时，我一定会误解。

提前感谢所有提供帮助的人。

+++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++

感谢各种论坛的帮助，该程序现在可以正常运行并创建它应该的输出文件。现在我需要创建一个程序来读入刚刚创建的文件。我没有把它全部放在第一篇文章中，以便能够将事情分解为步骤（如果你没有创建它，就无法在文件中读取。有点事）。如果我需要创建一个新线程，那么我会，但由于ppl熟悉该程序可能会读取这个，我将它发布在与编辑相同的线程中。

我现在需要做的是在GUI中列表底部添加另一个字段，根据刚刚创建的文件中读入的输入计算后的总薪酬。

重新说一下，第一个程序是创建文件。现在我需要阅读它并显示计算的总薪水。（链接到示例输出的photobucket图像：[URL =“http://i108.photobucket.com/albums/n24/zypher89/readPayroll.jpg”] http://i108.photobucket.com/albums/n24/zypher89/readPayroll.jpg[/URL]）

由于某种原因，java.sun.com网站已关闭（至少我无法访问它，甚至从不同网络上的不同计算机），所以我没有它作为参考。

这是我的代码，其中有错误已注释掉

[CODE]

包分配10_11;

import java.io. ; import java.awt。; import java.awt.event。; import javax.swing。;

公共类ReadPayrollFile扩展JFrame实现ActionListener，WindowListener {

public static final int WIDTH = 400;
public static final int HEIGHT = 300;
JPanel titlePanel = new JPanel();
JPanel displayPanel = new JPanel(new GridLayout(7, 1));
JPanel dPanel1 = new JPanel(new FlowLayout(FlowLayout.LEFT));
JPanel dPanel2 = new JPanel(new FlowLayout(FlowLayout.LEFT));
JPanel dPanel3 = new JPanel(new FlowLayout(FlowLayout.LEFT));
JPanel dPanel4 = new JPanel(new FlowLayout(FlowLayout.LEFT));
JPanel dPanel5 = new JPanel(new FlowLayout(FlowLayout.LEFT));
JPanel dPanel6 = new JPanel(new FlowLayout(FlowLayout.LEFT));
JPanel dPanel7 = new JPanel(new FlowLayout(FlowLayout.LEFT));
JPanel buttonPanel = new JPanel();
private JLabel companyName = new JLabel("Payroll INC.");
Font bigFont = new Font("Helvetica", Font.ITALIC, 24);
private JLabel prompt = new JLabel("Enter Payroll Information");
private JTextField employeeName = new JTextField(10);
private JTextField employeeNumber = new JTextField(10);
private JTextField hourlyRate = new JTextField(10);
private JTextField regularHours = new JTextField(10);
private JTextField overtimeHours = new JTextField(10);
private JTextField grossPay = new JTextField(10);
private JLabel enameLabel = new JLabel("Employee Name       ");
private JLabel enumLabel = new JLabel("Employee Number   ");
private JLabel hrLabel = new JLabel("Hourly Rate                ");
private JLabel rhLabel = new JLabel("Regular Hours          ");
private JLabel orLabel = new JLabel("Overtime Hours       ");
private JLabel gpLabel = new JLabel ("Gross Pay                 ");
private JButton nextRecordButton = new JButton("  Next Record  ");
DataInputStream fstream;

public ReadPayrollFile() {
    super("Read Payroll File - Assignment 11");

    setSize(WIDTH, HEIGHT);
    try
    {
        fstream = new DataInputStream(new FileInputStream("payroll.dat"));

    } catch (IOException e) {
        System.err.println("File not opened");
        System.exit(1);
    }
    Container contentPane = getContentPane();
    contentPane.setLayout(new BorderLayout());

    companyName.setFont(bigFont);
    titlePanel.add(companyName);
    titlePanel.setBackground(Color.white);

    dPanel1.add(prompt);
    displayPanel.add(dPanel1);

    dPanel2.add(enameLabel);
    dPanel2.add(employeeName);
    displayPanel.add(dPanel2);

    dPanel3.add(enumLabel);
    dPanel3.add(employeeNumber);
    displayPanel.add(dPanel3);

    dPanel4.add(hrLabel);
    dPanel4.add(hourlyRate);
    displayPanel.add(dPanel4);

    dPanel5.add(rhLabel);
    dPanel5.add(regularHours);
    displayPanel.add(dPanel5);

    dPanel6.add(orLabel);
    dPanel6.add(overtimeHours);
    displayPanel.add(dPanel6);

    dPanel7.add(gpLabel);
    dPanel7.add(grossPay);
    displayPanel.add(dPanel7);

    buttonPanel.setBackground(Color.white);
    buttonPanel.setLayout(new FlowLayout());
    nextRecordButton.setMnemonic(KeyEvent.VK_E);
    buttonPanel.add(nextRecordButton);
    nextRecordButton.addActionListener(this);

    contentPane.add(titlePanel, BorderLayout.NORTH);
    contentPane.add(displayPanel, BorderLayout.CENTER);
    contentPane.add(buttonPanel, BorderLayout.SOUTH);
    addWindowListener(this);
}

private void readRecord(DataInputStream inputFile) {

    String l_employeeName;
    Double l_hourlyRate;
    Integer l_employeeNumber, l_regularHours, l_overtimeHours;
    boolean endOfFile = false;

    try {

        while (!endOfFile)
        {
            try
            {
                /** This is where it says that the readChars() is undefined. The code posted
                 *  doesn't show it, but I have tried changing the output file program to 
                 *  write the string as a UTF and then changed this program to readUTF and it
                 *  works for "l_employeeName = inputFile.readChars();" but not for the 
                 *  "fstream.readChars(l_employeeName);". Also, all of the fstream lines have
                 *  errors "The method readInt() in the type DataInputStream is not applicable
                 *  for the arguments (Integer)" (replace Integer/Int with Double respectively).
                 */

                l_employeeName = inputFile.readUTF();
                l_employeeNumber = inputFile.readInt();
                l_hourlyRate = inputFile.readDouble();
                l_regularHours = inputFile.readInt();
                l_overtimeHours = inputFile.readInt();
                fstream.readUTF(l_employeeName);
                fstream.readInt(l_employeeNumber);
                fstream.readDouble(l_hourlyRate);
                fstream.readInt(l_regularHours);
                fstream.readInt(l_overtimeHours);

                calculateGrossPay(l_hourlyRate, l_regularHours, l_overtimeHours);

                employeeName.setText("l_employeeName");
                employeeNumber.setText("l_employeeNumber");
                hourlyRate.setText("l_hourlyRate");
                regularHours.setText("l_regularHours");
                overtimeHours.setText("l_overtimeHours");
                grossPay.setText("grossPayAmmount");
            } 

            catch (NumberFormatException e2) 
            {
                System.err.println("Invalid number ");
            }

            catch (IOException e3) 
            {
                System.err.println("Error reading file");
                System.exit(1);
            } //here I get error "Syntax error, insert "Finally" to complete TryStatement"
        }

        /** Then here I assume the instructor wants the program to
         *  read in the next set of employee data from the input file
         *   but he didn't specify and hasn't returned my email. So if 
         *   going with my assumption, how would I go about doing that?
         */
        public void actionPerformed(ActionEvent e) {
            NextRecord();
        }

        public void windowClosing(WindowEvent e) {
            try {
                fstream.close();
            } catch (IOException e4) {
                System.err.println("File not closed");
                System.exit(1);
            }

            System.exit(0);
        }

        public void windowClosed(WindowEvent e) {
        }

        public void windowDeiconified(WindowEvent e) {
        }

        public void windowIconified(WindowEvent e) {
        }

        public void windowOpened(WindowEvent e) {
        }

        public void windowActivated(WindowEvent e) {
        }

        public void windowDeactivated(WindowEvent e) {
        }

        public static void main(String[] args) {
            ReadPayrollFile cmof = new ReadPayrollFile();
            cmof.setVisible(true);
        }
        public double calculateGrossPay(double l_hourlyRate, int l_regularHours, int l_overtimeHours)
        {
            double grossPayAmmount, overtimePayRate, overtimePay;

            overtimePayRate = l_hourlyRate * 1.5;
            overtimePay = l_overtimeHours * overtimePayRate;
            grossPayAmmount = ((l_hourlyRate * l_regularHours) + overtimePay);

            return grossPayAmmount;
        }
    }

[/ CODE]

我将继续研究它并研究文件I / O以及尝试让API工作。

再次感谢大家的帮助。

Answer 1

对于所有setText方法：您有局部变量来覆盖类变量。试试这个：

private void writeRecord() {

    String l_employeeName;
    Double l_hourlyRate;
    Integer l_employeeNumber, l_regularHours, l_overtimeHours;


 // this is where I am having errors. It is saying that the getText method is undefined
 // for each respective use (int, string, double). I am also getting error "The method
 // writeString(String) is undefined for the type DataOutputStream" and the same 
 // undefined errors for the setText for each respective use. 

    try {
        l_employeeName = String.parseString(employeeName.getText());
        l_employeeNumber = Integer.parseInt(employeeNumber.getText());
        l_hourlyRate = Double.parseDouble(hourlyRate.getText());
        l_regularHours = Integer.parseInt(regularHours.getText());
        l_overtimeHours = Integer.parseInt(overtimeHours.getText());
        ostream.writeString(l_employeeName);
        ostream.writeInt(l_employeeNumber);
        ostream.writeDouble(l_hourlyRate);
        ostream.writeInt(l_regularHours);
        ostream.writeInt(l_overtimeHours);
        employeeName.setText("");
        employeeNumber.setText("");
        hourlyRate.setText("");
        regularHours.setText("");
        overtimeHours.setText("");

对于ostream.writeString：documentation for DataOutputStream表示没有ostream.writeString。尝试使用ostream.writeChars。

Answer 2

您犯了3个基本错误

writeRecord()中的局部变量与实例变量具有相同的名称，因此隐藏了它们。已经由Chip Uni +解决方案指出。
String类没有函数parseString(String)。检查javadoc（JDK API: String）。完全删除它，因为getText()无论如何都会返回String。
DataOutputStream没有功能writeString()使用writeChars()而不是

Answer 3

问题是您想要访问成员变量但实际访问局部变量。局部变量的名称实际上隐藏了您的成员变量！如果您定义这样的类

public class A {
  private int asdf = 0;

  public void blah() {
    String asdf = "Hello!";
    System.out.println(text);
  }

}

该程序将打印“你好！”如果你叫“等等”。这是因为局部变量“text”隐藏了同名的成员。您有两种选择：

选择不同的名称

public class A {
  private int aNumber = 0;

  public void blah() {
    String asdf = "Hello!";
    System.out.println(aNumber);
  }

}

使用它来访问会员此

   public class A {
      private int asdf = 0;

      public void blah() {
        String asdf = "Hello!";
        System.out.println(this.asdf);
      }

    }

Answer 4

查看java api

通过一些研究，您将找到原因

... getText方法未定义

你的字符串。

但我建议您使用IDE，即使是作业。

在Java I / O程序中遇到Try-Catch块问题

4 个答案: