得到某年某月的第一天和最后一天

import java.text.SimpleDateFormat;import java.util.Calendar;public class FirstEndOfMonth { /**  * 得到某年某月的第一天  *   * @param year  * @param month  * @return  */ public String getFirstDayOfMonth(int year, int month) {  Calendar cal = Calendar.getInstance();  cal.set(Calendar.YEAR, year);  cal.set(Calendar.MONTH, month-1);  cal.set(Calendar.DAY_OF_MONTH, cal.getMinimum(Calendar.DATE));  return new SimpleDateFormat("yyyy/MM/dd").format(cal.getTime()); }  /**  * 得到某年某月的最后一天  *   * @param year  * @param month  * @return  */  public String getLastDayOfMonth(int year, int month) {  Calendar cal = Calendar.getInstance();  cal.set(Calendar.YEAR, year);  cal.set(Calendar.MONTH, month-1);   cal.set(Calendar.DAY_OF_MONTH, 1);  int value = cal.getActualMaximum(Calendar.DAY_OF_MONTH);  cal.set(Calendar.DAY_OF_MONTH, value);  return new SimpleDateFormat("yyyy/MM/dd").format(cal.getTime()); } /**  *   * @param args  */ public static void main(String[] args) {  FirstEndOfMonth tFirstEndOfMonth = new FirstEndOfMonth();  System.out.println(tFirstEndOfMonth.getFirstDayOfMonth(2012, 2));  System.out.println(tFirstEndOfMonth.getLastDayOfMonth(2012, 2)); }}