时间工具类积累

时间工具类积累

import java.text.SimpleDateFormat;


import com.alibaba.dubbo.common.utils.StringUtils;


/**
 * 日期工具类
 * @author ouyang
 */
public class DateUtil {
	
	public static final String yyyyMMdd = "yyyyMMdd";  
	public static final String yyyyMM = "yyyyMM";  
	public static final String yyyy_MM_dd = "yyyy-MM-dd";  
	public static final String yyyy_mm_dd_hh24_mi_ss = "yyyy-mm-dd hh24:mi:ss";  
	public static final String yyyy_MM_dd_HH_mm_ss = "yyyy-MM-dd HH:mm:ss";  
	public static final String yyyyMMddHHmmssS = "yyyyMMddHHmmssS";
	
	/**
	 * 获取格式化对象
	 * @param formatter
	 * @return
	 */
	public static SimpleDateFormat format(String formatter){
		SimpleDateFormat localSimpleDateFormat = new SimpleDateFormat(formatter); 
		localSimpleDateFormat.setLenient(false); 
		return localSimpleDateFormat;
	}
	
	/**
	 * 字符串转时间，默认转成yyyy-MM-dd
	 * @param dateStr
	 * @return
	 */
	public static java.util.Date strToDate(String dateStr) { 
		try {  
		    return format(yyyy_MM_dd).parse(dateStr);  
		} catch (Exception localParseException) {  
		    return null;  
		}  
	}


	/**
	 * 字符串转时间
	 * @param dateStr
	 * 	目标字符串
	 * @param formatter
	 * 	转换格式
	 * @return
	 */
	public static java.util.Date strToDate(String dateStr, String formatter) {
		if(StringUtils.isBlank(formatter)){
			formatter = new String(yyyy_MM_dd);
		}
		SimpleDateFormat localSimpleDateFormat = new SimpleDateFormat(formatter);  
		localSimpleDateFormat.setLenient(false);  
		try {  
		    return localSimpleDateFormat.parse(dateStr);  
		} catch (Exception localParseException) {  
		    return null;  
		}  
	}

	/**
	 * 获取N天过后
	 * @param n
	 * @return
	 */
	public static String afterNDay(int n){
		Calendar c = Calendar.getInstance();
		DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
		c.setTime(new Date());
		c.add(Calendar.DATE,n);
		Date d2 = c.getTime();
		String s = df.format(d2);
		return s;
	}

}