提供一个时间操作类给你,你可以调用里面的dateDiff方法,dateDiff(new Date(), getDateFromString("明天的字符串")表示的就是现在到明天0点之前的差距天数。
你要分钟数的话就自己改一下dateDiff,不要除以60和24就是分钟了
以下是工具类代码
import org.apache.log4j.Loggerimport java.text.ParseException
import java.text.SimpleDateFormat
import java.util.Calendar
import java.util.Date
public class AdDateUtil {
private static Logger logger = Logger.getLogger(AdDateUtil.class)
static public String getNowStr(String format) {
SimpleDateFormat sdf = new SimpleDateFormat(format)
String now = sdf.format(new Date())
return now
}
static public Date getFormatDate(String date, String format) {
SimpleDateFormat sdf = new SimpleDateFormat(format)
Date d = new Date()
try {
d = sdf.parse(date)
} catch (ParseException e) {
logger.error(e)
}
return d
}
static public String getDateStr(Date date, String format) {
SimpleDateFormat sdf = new SimpleDateFormat(format)
String d = sdf.format(date)
return d
}
static public String getPadZeroString(String s, int size) {
StringBuffer sb = new StringBuffer()
for (int i = 0 i < (size - s.length()) i++) {
sb.append("0")
}
sb.append(s)
return sb.toString()
}
/**
* 得到某月的天数
*
* @param year
* @param month
* @return
*/
static public int getDayCountOfMonth(String year, String month) {
Calendar cal = Calendar.getInstance()
// 年
cal.set(Calendar.YEAR, Integer.parseInt(year))
// 月,因为Calendar里的月是从0开始,所以要-1
cal.set(Calendar.MONTH, Integer.parseInt(month) - 1)
return cal.getActualMaximum(Calendar.DAY_OF_MONTH)
}
static public String getYesterday(String format) {
SimpleDateFormat df = new SimpleDateFormat(format)
Calendar now = Calendar.getInstance()
now.roll(Calendar.DAY_OF_YEAR, -1) //昨天
return df.format(now.getTime())
}
/**
* 获取和今天附近的某天
* @param format
* @param diff
* @return
*/
static public String getADay(String format, int diff) {
SimpleDateFormat df = new SimpleDateFormat(format)
Calendar now = Calendar.getInstance()
int beforeM = now.get(Calendar.MONTH)
now.roll(Calendar.DAY_OF_YEAR, diff) //
int nowM = now.get(Calendar.MONTH)
//必须进行日期处理,否则2009-01-04日前七天是2009-12-28
if (nowM > beforeM) {
now.roll(Calendar.YEAR, -1)
}
return df.format(now.getTime())
}
static public String getTomorrow(String format) {
SimpleDateFormat df = new SimpleDateFormat(format)
Calendar now = Calendar.getInstance()
now.roll(Calendar.DAY_OF_YEAR, 1) //明天
return df.format(now.getTime())
}
/**
* 得到最近num天的全部日期
* 说明:
* 1.日期是从昨天开始算的.
* 2.如果num=2 , 日期是2008-03-14 ,则返回的结果为 2008-03-12、2008-03-13
* @param num
* @return
*/
public static String[] getDaysByNum(int num, String date) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd")
String[] result = { }
Calendar cal = Calendar.getInstance()
cal.setTime(getDateFromString(date, "yyyy-MM-dd"))
//最近一周
result = new String[num]
for (int i = num i > 0 i--) {
cal.add(Calendar.DAY_OF_YEAR, -1)
result[i - 1] = sdf.format(new Date(cal.getTimeInMillis()))
}
return result
}
public static Date getDateFromString(String dateStr, String format) {
if ((dateStr == null) || (format == null)) {
try {
throw new Exception("数据类型异常" + dateStr + "|" + format)
} catch (Exception e) {
logger.error("数据类型异常:" + e)
}
}
SimpleDateFormat df = new SimpleDateFormat(format)
Date date
try {
date = df.parse(dateStr)
return date
} catch (Exception ex) {
logger.error(ex)
return new Date()
}
}
static public int getNowYear() {
Calendar cal = Calendar.getInstance()
return cal.get(Calendar.YEAR)
}
static public int getNowMonth() {
Calendar cal = Calendar.getInstance()
return cal.get(Calendar.MONTH) + 1
}
public static String[] getMonthRang(String year, String month) {
String beginDate = year + "-" + month + "-01"
String endDate = year + "-" + month + "-" +
getDayCountOfMonth(year, month)
return getDaysByRang(beginDate, endDate)
}
public static String[] getDaysByRang(String beginDate, String endDate) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd")
//得到两个日期间相差多少天
int num = dateDiff(beginDate, endDate)
if (num < 0) {
//颠倒一下日期
String tmp = beginDate
beginDate = endDate
endDate = tmp
num = 0 - num
}
String[] result = { }
Calendar cal = Calendar.getInstance()
try {
cal.setTime(sdf.parse(beginDate))
} catch (ParseException e) {
e.printStackTrace()
}
num = num + 1 //把开始和结束日期都包含进去
result = new String[num]
for (int i = 0 i < num i++) {
if (i > 0) {
cal.add(Calendar.DAY_OF_YEAR, 1)
}
result[i] = sdf.format(new Date(cal.getTimeInMillis()))
}
return result
}
public static int dateDiff(String beginDate, String endDate) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd")
Date date = null
try {
date = sdf.parse(endDate)
} catch (ParseException e) {
date = new Date()
e.printStackTrace()
}
long end = date.getTime()
try {
date = sdf.parse(beginDate)
} catch (ParseException e) {
date = new Date()
e.printStackTrace()
}
long begin = date.getTime()
long day = (end - begin) / (1000 * 3600 * 24) //除1000是把毫秒变成秒
return Integer.parseInt(Long.toString(day))
}
public static void main(String[] args) {
System.out.println(AdDateUtil.getADay("yyyy-MM-dd", -7))
}
}
第一种是以毫秒为单位计算的。
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//伪代码
long startTime=System.currentTimeMillis() //获取开始时间
doSomeThing() //测试的代码段
long endTime=System.currentTimeMillis() //获取结束时间
System.out.println("程序运行时间: "+(end-start)+"ms")
第二种是以纳秒为单位计算的。
[java] view plain copy
//伪代码
long startTime=System.nanoTime() //获取开始时间
doSomeThing() //测试的代码段
long endTime=System.nanoTime() //获取结束时间
System.out.println("程序运行时间: "+(end-start)+"ns")
包含所需的包: import java.lang.System
1.计算天数差。
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String fromDate = simpleFormat.format("2016-05-01 12:00")
String toDate = simpleFormat.format("2016-06-01 12:00")
long from = simpleFormat.parse(fromDate).getTime()
long to = simpleFormat.parse(toDate).getTime()
int days = (int) ((to - from)/(1000 * 60 * 60 * 24))
2.计算小时差
[java] view plain copy
String fromDate = simpleFormat.format("2016-05-01 12:00")
String toDate = simpleFormat.format("2016-05-01 14:00")
long from = simpleFormat.parse(fromDate).getTime()
long to = simpleFormat.parse(toDate).getTime()
int hours = (int) ((to - from)/(1000 * 60 * 60))
3.计算分钟差:
[java] view plain copy
String fromDate = simpleFormat.format("2016-05-01 12:00")
String toDate = simpleFormat.format("2016-05-01 12:50")
long from = simpleFormat.parse(fromDate).getTime()
long to = simpleFormat.parse(toDate).getTime()
int minutes = (int) ((to - from)/(1000 * 60))