How to get start and end date for a specific month

问题:

I am creating a report in iReport

The user enters a date eg. 2014-09-14

The report then needs to print 2014-09-01 and 2014-09-30

("First day of selected month and year" and "Last day of selected month and year")

I've been trying to get it to work with

new java.util.Date(new java.util.GregorianCalendar($P{ds_endDate}.getYear(),$P{ds_endDate}.getMonth(),1).getTimeInMillis())
// end result must be java.util.Date 

But have had no luck

回答1:

If you like to do this inside jasper report a good way to go is using variable

Example: lets assume the date is arriving as a parameter (if you like naturally it can be a field, you just need to switch how the variable is calculated).

The incoming date (I use directly the java.util.Calendar as class and set a default value so that I can test in preview)

<parameter name="date" class="java.util.Calendar" isForPrompting="false">
    <defaultValueExpression><![CDATA[new GregorianCalendar()]]></defaultValueExpression>
</parameter>

The variable definition, this is beginning of month, create another variable for end of month using getActualMaximum instead of getActualMinimum

<variable name="beginningOfMonth" class="java.util.Calendar">
    <initialValueExpression><![CDATA[new java.util.GregorianCalendar($P{date}.get(Calendar.YEAR),$P{date}.get(Calendar.MONTH) ,$P{date}.getActualMinimum(Calendar.DAY_OF_MONTH))]]></initialValueExpression>
</variable>

since we are using a parameter its enough to set initialValueExpression if you are using a field you need to set the variableExpression

Thats it we have our date, format it as you like in the textField

Example

<textField>
  <reportElement x="22" y="11" width="100" height="20" uuid="1a094181-bcf1-469c-a786-77a0b7a3d533"/>
  <textFieldExpression><![CDATA[new java.text.SimpleDateFormat("yyyy-MM-dd").format($V{beginningOfMonth}.getTime())]]></textFieldExpression>
</textField>

Note: if you are using old version of jasper report (3.1 ecc) you need to set correct class on the different expression 's

回答2:

Try this out:

Calendar abc = new GregorianCalendar();
System.out.println(abc.getActualMaximum(Calendar.DAY_OF_MONTH) + " and " + abc.getActualMinimum(Calendar.DAY_OF_MONTH));

回答3:

I got it working by using some SQL in the query of the report and just printing that field

SQL looks like this

Select LAST_DAY('2014-09-14') lastDay,
DATE_ADD((DATE_ADD(LAST_DAY('2014-09-14') ,INTERVAL 1 DAY)) ,INTERVAL -1 MONTH) firstDay

Note: replace '2014-09-14'with input parameter on reprot eg. $P{dateEntered}