总结一下自己在Android开发中遇到的时间处理

//获取当前时间 如果****-01-01不是周一从第一个周一开始计算
	//设置每周的第一天为周一
	cal.setFirstDayOfWeek(Calendar.MONDAY);
	//设置每周从周一开始
	cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY); 
	//设置每周最少为7天 
	cal.setMinimalDaysInFirstWeek(7); 
	// 设置年度为指定的年 
	cal.set(Calendar.YEAR, cal.get(cal.YEAR));
	//设置判断时间
	cal.setTime(new Date());
	//根据情况返回日期为当前第几个周
	return cal.get(Calendar.WEEK_OF_YEAR);

//获取当前周的所有日期
cal.set(Calendar.WEEK_OF_YEAR, week);
		while (cal.get(Calendar.DAY_OF_WEEK) != FIRST_DAY) {
			cal.add(Calendar.DATE, -1);
		}
		for (int i = 0; i < 7; i++) {
			list.add(cal.getTime().getTime());
			cal.add(Calendar.DATE, 1);
		}
//区别第一种如果****-01-01不是周一的时候回从去年的最后一个周一开始计算
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
		Calendar cal = Calendar.getInstance();
		System.out.println(cal.get(Calendar.WEEK_OF_YEAR));
		cal.set(Calendar.WEEK_OF_YEAR, 52);
		while (cal.get(Calendar.DAY_OF_WEEK) != Calendar.MONDAY) {
			cal.add(Calendar.DATE, -1);
		}
		for (int i = 0; i < 7; i++) {
			System.out.println(sdf.format(cal.getTime()));
			cal.add(Calendar.DATE, 1);
		}
//计算某月的开始时间和结束时间
Calendar cal = Calendar.getInstance();
		cal.set(Calendar.MONTH, 月份);
		cal.set(Calendar.DAY_OF_MONTH, 1);
		System.out.println(sdf.format(cal.getTime()));
		cal.add(Calendar.DAY_OF_MONTH, -1);
		Date lastDate = cal.getTime();
		cal.set(Calendar.DAY_OF_MONTH, 1);
		Date firstDate = cal.getTime();
		System.out.println(sdf.format(lastDate)+""+sdf.format(firstDate));
		
//计算某月所有日期
list.add(sdf.format(dBegin));
		Calendar calBegin = Calendar.getInstance();  
		// 使用给定的 Date 设置此 Calendar 的时间    
		calBegin.setTime(dBegin);  
		Calendar calEnd = Calendar.getInstance();  
		// 使用给定的 Date 设置此 Calendar 的时间    
		calEnd.setTime(dEnd);  
		// 测试此日期是否在指定日期之后    
		while (dEnd.after(calBegin.getTime())) {  
			// 根据日历的规则，为给定的日历字段添加或减去指定的时间量    
			calBegin.add(Calendar.DAY_OF_MONTH, 1);  
			list.add(sdf.format(calBegin.getTime()));  
		}  
/**
	 * 得到本周周一
	 * 
	 * @return yyyy-MM-dd
	 */
	public static String getMondayOfThisWeek() {
		Calendar c = Calendar.getInstance();
		int dayofweek = c.get(Calendar.DAY_OF_WEEK) - 1;
		if (dayofweek == 0)
			dayofweek = 7;
		c.add(Calendar.DATE, -dayofweek + 1);
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		return sdf.format(c.getTime());
	}
	/**
	 * 得到本周周日
	 * 
	 * @return yyyy-MM-dd
	 */
	public static String getSundayOfThisWeek() {
		Calendar c = Calendar.getInstance();
		int dayofweek = c.get(Calendar.DAY_OF_WEEK) - 1;
		if (dayofweek == 0)
			dayofweek = 7;
		c.add(Calendar.DATE, -dayofweek + 7);
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		return sdf.format(c.getTime());
	}
//当前日期加几天
private String addDate(String date,int day){
		
		try {
			Date od=sdf.parse(date);
			Date nd=addDete(od, day);
			return sdf.format(nd);
		} catch (ParseException e) {
			e.printStackTrace();
		}
		return "";
	}
	public static Date addDete(Date d,long day) throws ParseException {
		long time = d.getTime(); 
		day = day*24*60*60*1000; 
		time+=day; 
		return new Date(time);
	}
//两日期相减得到之间天数(是String格式)
public static int daysBetween(String smdate,String bdate) throws ParseException{  
		Calendar cal = Calendar.getInstance();    
		cal.setTime(sdf.parse(smdate));    
		long time1 = cal.getTimeInMillis();                 
		cal.setTime(sdf.parse(bdate));    
		long time2 = cal.getTimeInMillis();         
		long between_days=(time2-time1)/(1000*3600*24);  
		return Integer.parseInt(String.valueOf(between_days));     
	}