Date Comparison using Java

Question

I have two dates    toDate  user input in MM dd yyyy format  currentDate  obtained by new Date       I need to compare the currentDate with toDate  I have to display a report only when the toDate is equal to or more than currentDate  How can I do that

User · Answer

Use java util Calendar if you have extensive date related processing   Date has before    after   methods  you could use them as well

User · Answer

If you re set on using Java Dates rather than  say  JodaTime  use a java text DateFormat to convert the string to a Date  then compare the two using  equals   I almost forgot  You need to zero out the hours  minutes  seconds  and milliseconds on the current date before comparing them   I used a Calendar object below to do it   import java text DateFormat  import java util Calendar  import java util Date      Other code here     String toDate        toDate    05 11 2010           Value assigned to toDate somewhere in here      DateFormat df   DateFormat getDateInstance DateFormat SHORT       Calendar currDtCal   Calendar getInstance            Zero out the hour  minute  second  and millisecond     currDtCal set Calendar HOUR OF DAY  0       currDtCal set Calendar MINUTE  0       currDtCal set Calendar SECOND  0       currDtCal set Calendar MILLISECOND  0        Date currDt   currDtCal getTime         Date toDt      try           toDt   df parse toDate         catch  ParseException e            toDt   null             Print some error message back to the user            if  currDt equals toDt                They re the same date

User · Answer

Date  long getTime   returns the number of milliseconds since January 1  1970  00 00 00 GMT represented by this Date object     test if date1 is before date2 if date1 getTime    lt  date2 getTime

User · Answer

Date equals   and Date after    If there is a possibility that the hour and minute fields are    0  you d have to set them to 0   I can t forget to mention that using java util Date is considered a bad practice  and most of its methods are deprecated  Use java util Calendar or JodaTime  if possible

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private boolean checkDateLimit          long CurrentDateInMilisecond   System currentTimeMillis       Date 1     long Date1InMilisecond   Date1 getTimeInMillis      Date2      if  CurrentDateInMilisecond  lt   Date1InMilisecond            return true        else           return false                Convert both date into milisecond value

User · Answer

This is one of the ways   String toDate    05 11 2010    if  new SimpleDateFormat  MM dd yyyy   parse toDate  getTime      1000   60   60   24   gt   System currentTimeMillis      1000   60   60   24         System out println  Display report       else       System out println  Don t display report         A bit more easy interpretable   String toDateAsString    05 11 2010   Date toDate   new SimpleDateFormat  MM dd yyyy   parse toDateAsString   long toDateAsTimestamp   toDate getTime    long currentTimestamp   System currentTimeMillis    long getRidOfTime   1000   60   60   24  long toDateAsTimestampWithoutTime   toDateAsTimestamp   getRidOfTime  long currentTimestampWithoutTime   currentTimestamp   getRidOfTime   if  toDateAsTimestampWithoutTime  gt   currentTimestampWithoutTime        System out println  Display report       else       System out println  Don t display report         Oh  as a bonus  the JodaTime s variant   String toDateAsString    05 11 2010   DateTime toDate   DateTimeFormat forPattern  MM dd yyyy   parseDateTime toDateAsString   DateTime now   new DateTime     if   toDate toLocalDate   isBefore now toLocalDate           System out println  Display report       else       System out println  Don t display report

User · Answer

If for some reason you re intent on using Date objects for your solution  you ll need to do something like this           Convert user input into year  month  and day integers     Date toDate   new Date year - 1900  month - 1  day   1       Date currentDate   new Date        boolean runThatReport   toDate after currentDate     Shifting the toDate ahead to midnight of the next day will take care of the bug I ve whined about in the comments to other answers   But  note that this approach uses a deprecated constructor  any approach relying on Date will use one deprecated method or another  and depending on how you do it may lead to race conditions as well  if you base toDate off of new Date   and then fiddle around with the year  month  and day  for instance    Use Calendar  as described elsewhere

User · Answer

You are probably looking for    toDate before currentDate    before   and after   test whether the date is strictly before or after  So you have to take the negation of the other one to get non strict behaviour

User · Answer

It is easier to compare dates using the java util Calendar  Here is what you might do   Calendar toDate   Calendar getInstance    Calendar nowDate   Calendar getInstance    toDate set  lt set-year gt   lt set-month gt   lt set-day gt      if  toDate before nowDate           display your report   else          don t display the report

[java] Date Comparison using Java

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