package com.dada.test;
 
 
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
 
/**
 * @author li_yueling
 * @version 1.0 2011-03-25
 *
 */
public class DateUtil {
    /**
     * 默认日期格式
     */
    public static String DEFAULT_FORMAT = "yyyy-MM-dd";
 
    /**
     * 测试主方法
     * @param args
     */
    public static void main(String[] args) {
        for(int i = 1951;i < 1960;i++){
            System.out.println(formatDate(getYearFirst(i)));
            System.out.println(formatDate(getYearLast(i)));
        }
         
        System.out.println(formatDate(getCurrYearFirst()));
        System.out.println(formatDate(getCurrYearLast()));
 
    }
     
    /**
     * 格式化日期
     * @param date 日期对象
     * @return String 日期字符串
     */
    public static String formatDate(Date date){
        SimpleDateFormat f = new SimpleDateFormat(DEFAULT_FORMAT);
        String sDate = f.format(date);
        return sDate;
    }
     
    /**
     * 获取当年的第一天
     * @param year
     * @return
     */
    public static Date getCurrYearFirst(){
        Calendar currCal=Calendar.getInstance();  
        int currentYear = currCal.get(Calendar.YEAR);
        return getYearFirst(currentYear);
    }
     
    /**
     * 获取当年的最后一天
     * @param year
     * @return
     */
    public static Date getCurrYearLast(){
        Calendar currCal=Calendar.getInstance();  
        int currentYear = currCal.get(Calendar.YEAR);
        return getYearLast(currentYear);
    }
     
    /**
     * 获取某年第一天日期
     * @param year 年份
     * @return Date
     */
    public static Date getYearFirst(int year){
        Calendar calendar = Calendar.getInstance();
        calendar.clear();
        calendar.set(Calendar.YEAR, year);
        Date currYearFirst = calendar.getTime();
        return currYearFirst;
    }
     
    /**
     * 获取某年最后一天日期
     * @param year 年份
     * @return Date
     */
    public static Date getYearLast(int year){
        Calendar calendar = Calendar.getInstance();
        calendar.clear();
        calendar.set(Calendar.YEAR, year);
        calendar.roll(Calendar.DAY_OF_YEAR, -1);
        Date currYearLast = calendar.getTime();
         
        return currYearLast;
    }
 
}