java时间日期使用与查询代码详解

时间：2022-12-02 12:39:28

只要格式正确，直接比较字符串就可以了呀，精确到秒的也一样

java" id="highlighter_301180">
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String  s1  =  "2003-12-12  11:30:24"; 
 String  s2  =  "2004-04-01  13:31:40"; 
 int  res  =  s1.compareTo(s2);

求日期差

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SimpleDateFormat  df  =  new  SimpleDateFormat("yyyy-MM-dd  HH:mm:ss"); 
 Date  begin=df.parse("2004-01-02  11:30:24"); 
 Date  end  =  df.parse("2004-03-26  13:31:40"); 
 long  between=(end.getTime()-begin.getTime())/1000;//除以1000是为了转换成秒 
 int  day=between/(24*3600); 
 int  hour=between%(24*3600)/3600; 
 int  minute=between%3600/60; 
 int  second=between%60;

经常用到时间日期类，所以就将常用的日期方法和属性都归纳总结如下，方便大家查找

1.计算某一月份的最大天数

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Calendar time=Calendar.getInstance();
time.clear();
time.set(Calendar.YEAR,year);
time.set(Calendar.MONTH,i-1);//注意,Calendar对象默认一月为0
int day=time.getActualMaximum(Calendar.DAY_OF_MONTH);//本月份的天数

注：在使用set方法之前，最好先clear一下，否则很多信息会继承自系统当前时间

2.Calendar和Date的转化

(1) Calendar转化为Date

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Calendar cal=Calendar.getInstance();
Date date=cal.getTime();

(2) Date转化为Calendar

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Date date=new Date();
Calendar cal=Calendar.getInstance();
cal.setTime(date);

3.格式化输出日期时间

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Date date=new Date();
SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
System.out.println(df.format(date));

4.计算一年中的第几星期

(1)计算某一天是一年中的第几星期

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Calendar cal=Calendar.getInstance();
cal.set(Calendar.YEAR, 2006);
cal.set(Calendar.MONTH, 9);
cal.set(Calendar.DAY_OF_MONTH, 3);
int weekno=cal.get(Calendar.WEEK_OF_YEAR);

(2)计算一年中的第几星期是几号

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SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd");
Calendar cal=Calendar.getInstance();
cal.set(Calendar.YEAR, 2006);
cal.set(Calendar.WEEK_OF_YEAR, 1);
cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
System.out.println(df.format(cal.getTime()));

输出:

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2006-01-02

5.add()和roll()的用法
(1)add()方法

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SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd");
Calendar cal=Calendar.getInstance();
cal.set(Calendar.YEAR, 2006);
cal.set(Calendar.MONTH, 9);
cal.set(Calendar.DAY_OF_MONTH, 3);
cal.add(Calendar.DATE, -4);
Date date=cal.getTime();
System.out.println(df.format(date));
cal.add(Calendar.DATE, 4);
date=cal.getTime();
System.out.println(df.format(date));

输出：
2006-08-30
2006-10-03

(2)roll方法

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cal.set(Calendar.YEAR, 2006);
cal.set(Calendar.MONTH, 9);
cal.set(Calendar.DAY_OF_MONTH, 3);
cal.roll(Calendar.DATE, -4);
date=cal.getTime();
System.out.println(df.format(date));
cal.roll(Calendar.DATE, 4);
date=cal.getTime();
System.out.println(df.format(date));

输出：

2006-10-29

2006-10-03

可见，roll()方法在本月内循环，一般使用add()方法；

6.计算两个任意时间中间的间隔天数

(1)传进Calendar对象

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/** */
/**计算两个时间之间相隔天数
* @param startday 开始时间
* @param endday 结束时间
* @return
*/
public int getIntervalDays(Calendar startday,Calendar endday)...{
    //确保startday在endday之前
    if(startday.after(endday))...{
        Calendar cal=startday;
        startday=endday;
        endday=cal;
    }
    //分别得到两个时间的毫秒数
    long sl=startday.getTimeInMillis();
    long el=endday.getTimeInMillis();
    long ei=el-sl;
    //根据毫秒数计算间隔天数
    return (int)(ei/(1000*60*60*24));
}

(2)传进Date对象

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/** */
/**计算两个时间之间相隔天数
* @param startday 开始时间
* @param endday 结束时间
* @return
*/
public int getIntervalDays(Date startday,Date endday)...{
    //确保startday在endday之前
    if(startday.after(endday))...{
        Date cal=startday;
        startday=endday;
        endday=cal;
    }
    //分别得到两个时间的毫秒数
    long sl=startday.getTime();
    long el=endday.getTime();
    long ei=el-sl;
    //根据毫秒数计算间隔天数
    return (int)(ei/(1000*60*60*24));
}

同理，可以用相同的方法计算出任意两个时间相隔的小时数，分钟数，秒钟数等
注：以上方法是完全按时间计算，有时并不能令人满意，如：

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startday="2006-10-11 20:00:00"
endday="2006-10-12 8:00:00"

计算结果为0，但是我们也许相让计算结果变为1，此时可以用如下方法实现：
在传参之前，先设定endday的时间，如：

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endday.set(Calendar.HOUR_OF_DAY, 23);
endday.set(Calendar.MINUTE, 59);
endday.set(Calendar.SECOND, 59);
endday.set(Calendar.MILLISECOND, 59);

这样再传进去startday,endday，则结果就如我们所愿了。不过，如果嫌以上方法麻烦，可以参考以下方法：
(3)改进精确计算相隔天数的方法

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public int getDaysBetween (Calendar d1, Calendar d2) ...{
    if (d1.after(d2)) ...{
        // swap dates so that d1 is start and d2 is end
        java.util.Calendar swap = d1;
        d1 = d2;
        d2 = swap;
    }
    int days = d2.get(Calendar.DAY_OF_YEAR) - d1.get(Calendar.DAY_OF_YEAR);
    int y2 = d2.get(Calendar.YEAR);
    if (d1.get(Calendar.YEAR) != y2) ...{
        d1 = (Calendar) d1.clone();
        do ...{
            days += d1.getActualMaximum(Calendar.DAY_OF_YEAR);
            //得到当年的实际天数
            d1.add(Calendar.YEAR, 1);
        }
        while (d1.get(Calendar.YEAR) != y2);
    }
    return days;
}

获取系统当前时间：

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public static String getSystemTime(){
    Date date=new Date();
    SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    return df.format(date);
}
//字符串转化成时间类型（字符串可以是任意类型，只要和SimpleDateFormat中的格式一致即可）
java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("M/dd/yyyy hh:mm:ss a",java.util.Locale.US);
java.util.Date d = sdf.parse("5/13/2003 10:31:37 AM");
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String mDateTime1=formatter.format(d);
//当前时间
Calendar cal = Calendar.getInstance();
// SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss G E D F w W a E F");
String mDateTime=formatter.format(cal.getTime());
//1年前日期
java.util.Date myDate=new java.util.Date();
long myTime=(myDate.getTime()/1000)-60*60*24*365;
myDate.setTime(myTime*1000);
String mDate=formatter.format(myDate);
//明天日期
myDate=new java.util.Date();
myTime=(myDate.getTime()/1000)+60*60*24;
myDate.setTime(myTime*1000);
mDate=formatter.format(myDate);
//两个时间之间的天数
SimpleDateFormat myFormatter = new SimpleDateFormat("yyyy-MM-dd");
java.util.Date date= myFormatter.parse("2003-05-1");
java.util.Date mydate= myFormatter.parse("1899-12-30");
long day=(date.getTime()-mydate.getTime())/(24*60*60*1000);
//加半小时
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
java.util.Date date1 = format.parse("2002-02-28 23:16:00");
long Time=(date1.getTime()/1000)+60*30;
date1.setTime(Time*1000);
String mydate1=formatter.format(date1);
//年月周求日期
SimpleDateFormat formatter2 = new SimpleDateFormat("yyyy-MM F E");
java.util.Date date2= formatter2.parse("2003-05 5 星期五");
SimpleDateFormat formatter3 = new SimpleDateFormat("yyyy-MM-dd");
String mydate2=formatter3.format(date2);
//求是星期几
mydate= myFormatter.parse("2001-1-1");
SimpleDateFormat formatter4 = new SimpleDateFormat("E");
String mydate3=formatter4.format(mydate);

在开发web应用中，针对不同的数据库日期类型，我们需要在我们的程序中对日期类型做各种不同的转换。若对应数据库数据是oracle的Date类型，即只需要年月日的，可以选择使用java.sql.Date类型，若对应的是MSsqlserver数据库的DateTime类型，即需要年月日时分秒的，选择java.sql.Timestamp类型

你可以使用dateFormat定义时间日期的格式，转一个字符串即可

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package personal.jessica;
import java.util.Date;
import java.util.Calendar;
import java.sql.Timestamp;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Locale;
class Datetest{
    /**
*method 将字符串类型的日期转换为一个timestamp（时间戳记java.sql.Timestamp）
*@param dateString 需要转换为timestamp的字符串
*@return dataTime timestamp
*/
    public final static java.sql.Timestamp string2Time(String dateString) 
    throws java.text.ParseException {
        DateFormat dateFormat;
        dateFormat = new SimpleDateFormat("yyyy-MM-dd kk:mm:ss.SSS", Locale.ENGLISH);
        //设定格式 
        //dateFormat = new SimpleDateFormat("yyyy-MM-dd kk:mm:ss", Locale.ENGLISH); 
        dateFormat.setLenient(false);
        java.util.Date timeDate = dateFormat.parse(dateString);
        //util类型 
        java.sql.Timestamp dateTime = new java.sql.Timestamp(timeDate.getTime());
        //Timestamp类型,timeDate.getTime()返回一个long型 
        return dateTime;
    }
    /**
*method 将字符串类型的日期转换为一个Date（java.sql.Date）
*@param dateString 需要转换为Date的字符串
*@return dataTime Date
*/
    public final static java.sql.Date string2Date(String dateString) 
    throws java.lang.Exception {
        DateFormat dateFormat;
        dateFormat = new SimpleDateFormat("yyyy-MM-dd", Locale.ENGLISH);
        dateFormat.setLenient(false);
        java.util.Date timeDate = dateFormat.parse(dateString);
        //util类型 
        java.sql.Date dateTime = new java.sql.Date(timeDate.getTime());
        //sql类型 
        return dateTime;
    }
    public static void main(String[] args){
        Date da = new Date();
        //注意：这个地方da.getTime()得到的是一个long型的值 
        System.out.println(da.getTime());
        //由日期date转换为timestamp 
        //第一种方法：使用new Timestamp(long) 
        Timestamp t = new Timestamp(new Date().getTime());
        System.out.println(t);
        //第二种方法：使用Timestamp(int year,int month,int date,int hour,int minute,int second,int nano) 
        Timestamp tt = new Timestamp(Calendar.getInstance().get( 
        Calendar.YEAR) - 1900, Calendar.getInstance().get( 
        Calendar.MONTH), Calendar.getInstance().get( 
        Calendar.DATE), Calendar.getInstance().get( 
        Calendar.HOUR), Calendar.getInstance().get( 
        Calendar.MINUTE), Calendar.getInstance().get( 
        Calendar.SECOND), 0);
        System.out.println(tt);
        try {
            String sToDate = "2005-8-18";
            //用于转换成java.sql.Date的字符串 
            String sToTimestamp = "2005-8-18 14:21:12.123";
            //用于转换成java.sql.Timestamp的字符串 
            Date date1 = string2Date(sToDate);
            Timestamp date2 = string2Time(sToTimestamp);
            System.out.println("Date:"+date1.toString());
            //结果显示 
            System.out.println("Timestamp:"+date2.toString());
            //结果显示
        }
        catch(Exception e) {
            e.printStackTrace();
        }
    }
}

下面是例子：

Java代码

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package test;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Hashtable;
import javax.swing.JOptionPane;
public class Test2{
    public static Boolean isdate(String s){
        String a[]=s.split("-");
        Boolean flg=true;
        if(!(Integer.parseint(a[0])>=1950 && Integer.parseint(a[0])<=2050)){
            flg=false;
        }
        return flg;
    }
    public static Boolean checkDate(String s){
        Boolean ret = true;
        try{
            DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
            ret = df.format(df.parse(s)).equals(s);
        }
        catch(ParseException e){
            ret = false;
        }
        return ret;
    }
    public Object dateinfo(String s){
        String a[]=s.split("-",2);
        Hashtable fest =new Hashtable();
        fest.put("01-01","元旦节");
        fest.put("02-14","情人节");
        fest.put("03-12","植树节");
        fest.put("03-15","消费者节");
        fest.put("04-01","愚人节");
        fest.put("04-05","清明节");
        fest.put("05-01","劳动节");
        fest.put("06-01","儿童节");
        fest.put("07-01","建党节");
        fest.put("08-01","建军节");
        fest.put("09-10","教师节");
        fest.put("10-01","国庆节");
        fest.put("12-25","圣诞节");
        if(fest.containsKey(a[1])){
            return fest.get(a[1]);
        } else{
            return "无节日";
        }
    }
    public String xingzuo(Date s){
        Calendar cal = Calendar.getInstance();
        cal.setTime(s);
        String xingzuo="无";
        int day=cal.get(Calendar.DAY_OF_YEAR);
        if((cal.get(Calendar.YEAR)%4==0)&&(cal.get(Calendar.YEAR)%100!=0)||(cal.get(Calendar.YEAR)%400==0)){
            if((day>=1 &&day<=19)||(day>=357&&day<=366)){
                xingzuo= "魔蝎座";
            } else if(day>=20 &&day<=49){
                xingzuo= "水瓶座";
            } else if(day>=50 &&day<=80){
                xingzuo= "双鱼座";
            } else if(day>=81 &&day<=110){
                xingzuo= "白羊座";
            } else if(day>=111 &&day<=141){
                xingzuo= "金牛座";
            } else if(day>=142 &&day<=173){
                xingzuo= "双子座";
            } else if(day>=174 &&day<=203){
                xingzuo= "巨蟹座";
            } else if(day>=204 &&day<=235){
                xingzuo= "狮子座";
            } else if(day>=236 &&day<=266){
                xingzuo= "处女座";
            } else if(day>=267 &&day<=296){
                xingzuo= "天秤座";
            } else if(day>=297 &&day<=326){
                xingzuo= "天蝎座";
            } else if(day>=327 &&day<=356){
                xingzuo= "射手座";
            }
        } else{
            if((day>=1 &&day<=19)||(day>=357&&day<=366)){
                xingzuo= "魔蝎座";
            } else if(day>=20 &&day<=48){
                xingzuo= "水瓶座";
            } else if(day>=49 &&day<=79){
                xingzuo= "双鱼座";
            } else if(day>=80 &&day<=109){
                xingzuo= "白羊座";
            } else if(day>=110 &&day<=140){
                xingzuo= "金牛座";
            } else if(day>=141 &&day<=172){
                xingzuo= "双子座";
            } else if(day>=173 &&day<=202){
                xingzuo= "巨蟹座";
            } else if(day>=203 &&day<=234){
                xingzuo= "狮子座";
            } else if(day>=235 &&day<=265){
                xingzuo= "处女座";
            } else if(day>=266 &&day<=295){
                xingzuo= "天秤座";
            } else if(day>=296 &&day<=325){
                xingzuo= "天蝎座";
            } else if(day>=326 &&day<=355){
                xingzuo= "射手座";
            }
        }
        return xingzuo;
    }
    public Date parseDate(String s){
        SimpleDateFormat bartDateFormat = new SimpleDateFormat("yyyy-MM-dd");
        try {
            Date date3 = bartDateFormat.parse(s);
            date3=bartDateFormat.parse(s);
            return date3;
        }
        catch (Exception ex) {
            return null;
        }
    }
    public static void main(String[] args) {
        Calendar cal = Calendar.getInstance();
        Test2 test2=new Test2();
        String date1=JOptionPane.showInputDialog("请你输入日期，格式如2000-10-15");
        while(!(Test2.checkDate(date1)&&Test2.isdate(date1))){
            date1=JOptionPane.showInputDialog("请你输入日期，格式如2000-10-15");
        }
        SimpleDateFormat bartDateFormat1 = new SimpleDateFormat("yyyy,MM,dd,EEEE");
        SimpleDateFormat bartDateFormat2 = new SimpleDateFormat("yyyy-MM-dd");
        Date date2=test2.parseDate(date1);
        String festinfo=(String)test2.dateinfo(date1);
        System.out.println(bartDateFormat1.format(date2) +","+ festinfo+","+ test2.xingzuo(date2));
        String day=JOptionPane.showInputDialog("请你输入要查询N天后的日期信息");
        cal.setTime(date2);
        cal.add(Calendar.DATE, Integer.parseint(day));
        String date5=bartDateFormat2.format(cal.getTime());
        festinfo=(String)test2.dateinfo(date5);
        System.out.println(bartDateFormat1.format(cal.getTime())+","+ festinfo+","+ test2.xingzuo(cal.getTime()));
    }
}

总结

以上就是本文关于java时间日期使用与查询代码详解的全部内容，希望对大家有所帮助。感兴趣的朋友可以继续参阅本站其他相关专题，如有不足之处，欢迎留言指出。感谢朋友们对本站的支持！

原文链接：http://blog.csdn.net/adayabetter/article/details/44596597

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