Here you can find the source of getLastDayOfMonth(String year, String month)
public static String getLastDayOfMonth(String year, String month) throws ParseException
//package com.java2s; //License from project: Apache License import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; public class Main { public final static String YYYY_MM_DD = "yyyy-MM-dd"; public static String getLastDayOfMonth(String year, String month) throws ParseException { String LastDay = ""; Calendar cal = Calendar.getInstance(); Date date_;/*from w w w. ja v a 2 s. co m*/ Date date = new SimpleDateFormat("yyyy-MM-dd").parse(year + "-" + month + "-14"); cal.setTime(date); int value = cal.getActualMaximum(Calendar.DAY_OF_MONTH); cal.set(Calendar.DAY_OF_MONTH, value); date_ = cal.getTime(); LastDay = new SimpleDateFormat("yyyy-MM-dd").format(date_); return LastDay; } public static Date parse(String strDate, String pattern) throws ParseException { try { return getFormatter(pattern).parse(strDate); } catch (ParseException pe) { throw new ParseException("Method parse in Class DateUtil err: parse strDate fail.", pe.getErrorOffset()); } } public static String format(Date date, String pattern) { if (date == null) return ""; else return getFormatter(pattern).format(date); } public static String format(Date date) { if (date == null) return ""; else return getFormatter(YYYY_MM_DD).format(date); } public static Date format(String strDate) { Date d = null; if (strDate == "") return null; else try { d = getFormatter(YYYY_MM_DD).parse(strDate); } catch (ParseException pex) { return null; } return d; } public static Date format(String strDate, String f) { Date d = null; if (strDate == "") return null; else try { d = getFormatter(f).parse(strDate); } catch (ParseException pex) { return null; } return d; } private static SimpleDateFormat getFormatter(String parttern) { return new SimpleDateFormat(parttern); } }