exercise13_17.java

java程序设计 机械工业出版社 书籍代码

// Exercise13_17.java
import java.awt.*;
import javax.swing.*;
import java.util.*;
import javax.swing.border.*;

public class Exercise13_17 extends JFrame {
    public Exercise13_17() {
        Container container = getContentPane();
        container.add(new CalendarPanel());
    }
    
    public static void main(String[] args) {
        Exercise13_17 frame = new Exercise13_17();
        frame.setTitle("Exercise13_17");
        frame.setSize(400, 400);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
    
    public class CalendarPanel extends JPanel {
        private Calendar calendar = new GregorianCalendar();
        private int month = calendar.get(Calendar.MONTH);
        private int year = calendar.get(Calendar.YEAR);        
        private int daysInMonth = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);

        // The header label
        private JLabel jlblHeader = new JLabel(month + 1 + "/" + year, JLabel.CENTER);
        
        // Labels to display day names and days
        private JLabel[] jlblDay = new JLabel[49];
        
        public CalendarPanel() {
            calendar.set(Calendar.DAY_OF_MONTH, 1); // Set calendar to the first day in a month
            int firstDay = calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH);
            
            // Panel jpDays to hold day names and days
            JPanel jpDays = new JPanel(new GridLayout(6, 7));
            
            jpDays.add(new JLabel("Sunday", JLabel.CENTER));
            jpDays.add(new JLabel("Monday", JLabel.CENTER));
            jpDays.add(new JLabel("Tuesday", JLabel.CENTER));
            jpDays.add(new JLabel("Wednesday", JLabel.CENTER));
            jpDays.add(new JLabel("Thursday", JLabel.CENTER));
            jpDays.add(new JLabel("Friday", JLabel.CENTER));
            jpDays.add(new JLabel("Saturday", JLabel.CENTER));
            
            for (int i = 0; i < firstDay; i++)
                jpDays.add(new JLabel());
            
            for (int i = 1; i <= daysInMonth; i++) {
                jpDays.add(jlblDay[i] = new JLabel(i + ""));
                jlblDay[i].setBorder(new LineBorder(Color.black, 1));
                jlblDay[i].setHorizontalAlignment(JLabel.RIGHT);
                jlblDay[i].setVerticalAlignment(JLabel.TOP);
            }
            
            // Place header and calendar body in the panel
            this.setLayout(new BorderLayout());
            this.add(jlblHeader, BorderLayout.NORTH);
            this.add(jpDays, BorderLayout.CENTER);
        }
    }
}