时间的常用操作

1：获取当前的年月日：

public static String[] getCurrentMonthRequestDate(){

Calendar ca = Calendar.getInstance();

int year = ca.get(Calendar.YEAR);

int month = ca.get(Calendar.MONTH)+1;

int day = ca.get(Calendar.DATE);

String monthString = null;

if(String.valueOf(month).length()==1){

monthString = "0"+month;

}else{

monthString = String.valueOf(month);

}

String dayString = null;

if(String.valueOf(day).length()==1){

dayString = "0"+day;

}else{

dayString = String.valueOf(day);

}

String end = String.valueOf(year)+monthString+dayString;

String start = String.valueOf(year)+monthString+"01";

return new String[]{start,end};

}

2：判断 某年某月 有几天:

 Calendar c= Calendar.getInstance();

 c.set(Calendar.YEAR, Integer.parseInt("2013"));

 c.set(Calendar.MONTH, Integer.parseInt("1"));

 System.out.println(c.getActualMaximum(Calendar.DAY_OF_MONTH)); 

3:格式化当前时分秒：

private static SimpleDateFormat dateFormat = new SimpleDateFormat(
"MM-dd HH:mm:ss");

String timeCurrent = dateFormat.format(new Date(System.currentTimeMillis()));

4：返回昨天日期

public  String getYesteday(){
long today = 0;
String yestedayString ;
SimpleDateFormat oldDateFormat = new SimpleDateFormat("yyyy-MM-dd");
try {
String oldDa = new Date().toLocaleString();


Date oldDate = oldDateFormat.parse(oldDa);
today = oldDate.getTime();
System.out.println(today);
long yesteday = today -(24*60*60*1000); //单位是毫秒



Date lastDate = new Date(yesteday);

5、其他

package com.zftlive.android.tools;import android.util.Log;import java.text.DateFormat;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Date;public class ToolDateTime {/** 日期格式：yyyy-MM-dd HH:mm:ss **/public static final String DF_YYYY_MM_DD_HH_MM_SS = "yyyy-MM-dd HH:mm:ss";/** 日期格式：yyyy-MM-dd HH:mm **/public static final String DF_YYYY_MM_DD_HH_MM = "yyyy-MM-dd HH:mm";/** 日期格式：yyyy-MM-dd **/public static final String DF_YYYY_MM_DD = "yyyy-MM-dd";/** 日期格式：HH:mm:ss **/public static final String DF_HH_MM_SS = "HH:mm:ss";/** 日期格式：HH:mm **/public static final String DF_HH_MM = "HH:mm";private final static long minute = 60 * 1000;// 1分钟private final static long hour = 60 * minute;// 1小时private final static long day = 24 * hour;// 1天private final static long month = 31 * day;// 月private final static long year = 12 * month;// 年/** Log输出标识 **/private static final String TAG = ToolDateTime.class.getSimpleName();/** * 将日期格式化成友好的字符串：几分钟前、几小时前、几天前、几月前、几年前、刚刚 *  * @param date * @return */public static String formatFriendly(Date date) {if (date == null) {return null;}long diff = new Date().getTime() - date.getTime();long r = 0;if (diff > year) {r = (diff / year);return r + "年前";}if (diff > month) {r = (diff / month);return r + "个月前";}if (diff > day) {r = (diff / day);return r + "天前";}if (diff > hour) {r = (diff / hour);return r + "个小时前";}if (diff > minute) {r = (diff / minute);return r + "分钟前";}return "刚刚";}/** * 将日期以yyyy-MM-dd HH:mm:ss格式化 *  * @param dateL *            日期 * @return */public static String formatDateTime(long dateL) {SimpleDateFormat sdf = new SimpleDateFormat(DF_YYYY_MM_DD_HH_MM_SS);Date date = new Date(dateL);return sdf.format(date);}/** * 将日期以yyyy-MM-dd HH:mm:ss格式化 *  * @param dateL *            日期 * @return */public static String formatDateTime(long dateL, String formater) {SimpleDateFormat sdf = new SimpleDateFormat(formater);return sdf.format(new Date(dateL));}/** * 将日期以yyyy-MM-dd HH:mm:ss格式化 *  * @param dateL *            日期 * @return */public static String formatDateTime(Date date, String formater) {SimpleDateFormat sdf = new SimpleDateFormat(formater);return sdf.format(date);}/** * 将日期字符串转成日期 *  * @param strDate *            字符串日期 * @return java.util.date日期类型 */public static Date parseDate(String strDate) {DateFormat dateFormat = new SimpleDateFormat(DF_YYYY_MM_DD_HH_MM_SS);Date returnDate = null;try {returnDate = dateFormat.parse(strDate);} catch (ParseException e) {Log.v(TAG, "parseDate failed !");}return returnDate;}/** * 获取系统当前日期 *  * @return */public static Date gainCurrentDate() {return new Date();}/** * 验证日期是否比当前日期早 *  * @param target1 *            比较时间1 * @param target2 *            比较时间2 * @return true 则代表target1比target2晚或等于target2，否则比target2早 */public static boolean compareDate(Date target1, Date target2) {boolean flag = false;try {String target1DateTime = ToolDateTime.formatDateTime(target1,DF_YYYY_MM_DD_HH_MM_SS);String target2DateTime = ToolDateTime.formatDateTime(target2,DF_YYYY_MM_DD_HH_MM_SS);if (target1DateTime.compareTo(target2DateTime) <= 0) {flag = true;}} catch (Exception e1) {System.out.println("比较失败，原因：" + e1.getMessage());}return flag;}/** * 对日期进行增加操作 *  * @param target *            需要进行运算的日期 * @param hour *            小时 * @return */public static Date addDateTime(Date target, double hour) {if (null == target || hour < 0) {return target;}return new Date(target.getTime() + (long) (hour * 60 * 60 * 1000));}/** * 对日期进行相减操作 *  * @param target *            需要进行运算的日期 * @param hour *            小时 * @return */public static Date subDateTime(Date target, double hour) {if (null == target || hour < 0) {return target;}return new Date(target.getTime() - (long) (hour * 60 * 60 * 1000));}}