如何由年份和星期而得到当年所有的日期(月日)

参考：http://community.csdn.net/Expert/TopicView.asp?id=5383638
/**
 * Calendar test 根据年份，打印该年日历
 * @author
 *
 */
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.TextArea;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.util.Calendar;
import java.util.GregorianCalendar;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class LeapYearTest extends JFrame implements ActionListener {
/**
 *
 */
private static final long serialVersionUID = 1L;

JLabel result;

TextArea txa;

JTextField t1;

JButton btn;
int year;

boolean leap;

int weekDay;

public LeapYearTest() {
super("Calendar Test");

setSize(280, 700);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Dimension dimension = Toolkit.getDefaultToolkit().getScreenSize();
setLocation(dimension.width / 2 - 140, dimension.height / 2 - 350);

JPanel panel = new JPanel();
result = new JLabel("year");
t1 = new JTextField(5);
t1.setToolTipText("input the year > 0");
btn = new JButton("generate");

t1.addKeyListener(new KeyAdapter() {
public void keyTyped(KeyEvent e) {
char input = e.getKeyChar();
if(input == ‘\n‘)
generate();
else if (!Character.isDigit(input) && input != ‘\b‘) {
e.consume();
}else{
btn.setEnabled(true);
}
}
public void keyPressed(KeyEvent e) {
}
public void keyReleased(KeyEvent e) {
}
});
btn.setToolTipText("Generate the year " + t1.getText() + " Calendar");
btn.setEnabled(false);
panel.add(result);
panel.add(t1);
panel.add(btn);

txa = new TextArea("", 12, 36, TextArea.SCROLLBARS_VERTICAL_ONLY);
txa.setEditable(false);
this.getContentPane().setLayout(new BorderLayout());
this.getContentPane().add(panel, "North");
this.getContentPane().add(txa, "Center");
btn.addActionListener(this);

}

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

private void generate()
{
System.out.println(t1.getText());
if(t1.getText() == null || t1.getText().equals("")){
return;
}
year = Integer.parseInt(t1.getText());
t1.setText("");
if (year < 1) {
txa.setText("year canot be less than 1！");
return;
}
else
txa.setText("          Calendar Year:" + year + "\n");
weekDay = (int) firstDayOfYear(year);
for (int i = 1; i <= 12; i++) {
printMonth(i);
//System.out.println("\n");
txa.append("\n");
}
t1.setText("");
btn.setEnabled(false);
}
private void printMonth(int m) {
printHead(m);
int days = daysOfMonth(m);
Calendar calendar = new GregorianCalendar();
for (int i = 1; i <= days; i++) {
if (i < 10) {
//System.out.print("   " + i);
txa.append("   " + i);
} else {
//System.out.print("  " + i);
txa.append("  " + i);
}
if(m == calendar.get(Calendar.MONTH)+1 && i == calendar.get(Calendar.DAY_OF_MONTH))
txa.append("*");
weekDay = (weekDay + 1) % 7;
if (weekDay == 0) {
//System.out.println();
txa.append("\n");
//System.out.print("");// 控制2-6行
//txa.append("");
}
}
}

private void printHead(int m) {

//System.out.println("========================================");
//System.out.println("  *日  一  二  三  四  五  六*    " + m + "月");
//System.out.println("========================================");

txa.append("========================================\n");
txa.append("  日  一  二  三  四  五  六    " + m + "月\n");
txa.append("========================================\n");
for (int i = 0; i < weekDay; i++) {
//System.out.print("    ");// 控制第一行
txa.append("    ");
}
}

private long firstDayOfYear(int y) {
long n;
n = y * 365;
for (int i = 1; i < y; i++) {
if (isLeapYear(i))
n += 1;
}
return n %= 7;
}

private int daysOfMonth(int m) {
switch (m) {
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
return 31;
case 4:
case 6:
case 9:
case 11:
return 30;
case 2:
if (isLeapYear(year))
return 29;
else
return 28;
}
return weekDay;
}

private boolean isLeapYear(int y) {
return ((y % 4 == 0 && y % 100 != 0) || y % 400 == 0);
}

public static void main(String[] args) {
LeapYearTest test = new LeapYearTest();
test.setVisible(true);
test.setAlwaysOnTop(true);
//test.setExtendedState(JFrame.MAXIMIZED_BOTH);
JFrame.setDefaultLookAndFeelDecorated(true);
}
}