Thread: Java beginner code not working in Ireport :(

I have member IDs and their date of births so I need to generate this final structure: member ID + First Capital letter of birth month +2 digit day of birth

member ID: 123456
DOB: 6/7/2011
final result: 123456J07

here are the fields in my Ireport:

member ID: $F{localId} Expression Class: (java.lang.String)

DOB: $F{person}.getDob() Expression Classjava.lang.string) Patttern: MM/dd/yyyy

I am having issues with the cast to string error so can anyone help create the right code? here is my code below:

CONCATENATE($F{localId},LEFT(new SimpleDateFormat("MM", Locale.ENGLISH).format($F{person}.getDob())),new SimpleDateFormat("dd").format($F{person}.getDob()) )

Thanks for any help.

SimpleDateFormat.format() expects a java.util.Date object or a java.lang.Number object, not a String. If you need to convert a String like "09/27/2017" into a Date object, that sounds like a job for SimpleDateFormat.parse() instead.

so how would I change this code or is there a better way? CONCATENATE($F{localId},LEFT(new SimpleDateFormat("MM", Locale.ENGLISH).format($F{person}.getDob())),new SimpleDateFormat("dd").format($F{person}.getDob()) )

Thanks

--- Update ---

so I changed the coding to this: CONCATENATE($F{localId},LEFT(new SimpleDateFormat.parse($F{person}.getDob())),Simpl eDateFormat.parse("dd")($F{person}.getDob()))

I am getting this error: Element type "topPen" must be declared.

Sounds like you're past the initial ClassCastException and on to something else now. Are you building an XML document with this output? Is there an XSD or DTD somewhere that requires a "topPen" element to exist in the XML? I'm not at all familiar with Ireport, but I'd look around for that kind of thing.

yes it is an XML format definition. This is part of that format definition at the beginning if that will help?

<?xml version="1.0" encoding="UTF-8" ?>
<!-- Created with iReport - A designer for JasperReports -->
<!DOCTYPE jasperReport PUBLIC "//JasperReports//DTD Report Design//EN" "http://jasperreports.sourceforge.net/dtds/jasperreport.dtd">
<jasperReport

The structure of your XML document is beyond what I can help with. I cannot access that DTD file, nor do I know Ireport or JasperReports at all. What I can say is, your resulting XML document does not have an element called "topPen" and that DTD is requiring it to exist. For more help on that, I'd suggest creating a new question, with Ireport or JasperReports in the subject line, so people who are familiar with those tools can see your post and help.

But I would like to point out that you should print out the result of your change. You're not getting what you expect by directly calling SimpleDateFormat.parse(). It probably looks more like "Fri Jan 07 00:06:00 EST 2011", not "J07" like you want. That's because SimpleDateFormat.parse() returns a java.util.Date object, and its toString() function does its own formatting. To get the individual fields (day, month, year, etc.) from a Date, use GregrorianCalendar and the Calendar constants like this:

String dobString = "6/7/2011";
Date dob = new SimpleDateFormat("MM/dd/yyyy").parse(dobString);
 
GregorianCalendar cal = new GregorianCalendar();
cal.setTime(dob);
int birthMonth = cal.get(Calendar.MONTH);
int birthDay = cal.get(Calendar.DAY_OF_MONTH);

The months are zero-based, so if birthMonth is 0 then it's January, 1 is February, etc. They do this so you can make a lookup table with your own date names:

String[] monthNames = new String[] {
	"J","F","M","A", // etc...
};
String monthName = monthNames[birthMonth];

Hi,

I thought you got the ClassCastException resolved when you changed it to use SimpleDateFormat.parse() instead of format().

CONCATENATE($F{localId},LEFT(new SimpleDateFormat.parse($F{person}.getDob())),Simpl eDateFormat.parse("dd")($F{person}.getDob()))

Can you please try the following and post the output of the two print statements?

Object dobObject = $F{person}.getDob();
System.out.println("dobObject [" + dobObject.getClass().getName() +"]: " + dobObject);
Date dobDate = new SimpleDateFormat("MM/dd/yyyy").parse(dobObject.toString());
System.out.println("dobDate: " + dobDate);

Once you have the Date object, use the GregorianCalendar to get the date formatted as "J07" like you need. In my last post, I showed you everything you need to do that. Once you have it formatted like "J07", the final result should look something like this:

CONCATENATE($F{localId}, dobString);

(Note that we're not using LEFT anymore. That function is no good for the kind of formatting you need here.)

so here is the errors that came back with this code: CONCATENATE($F{localId},LEFT(new SimpleDateFormat.parse($F{person}.getDob())),Simpl eDateFormat.parse("dd")($F{person}.getDob()))

Errors were encountered when compiling report expressions class file:
1. SimpleDateFormat.parse cannot be resolved to a type
value = CONCATENATE(((java.lang.String)field_localId.getVa lue()),LEFT(new SimpleDateFormat.parse(((com.x2dev.sis.model.beans .SisPerson)field_person.getValue()).getDob())),Sim pleDateFormat.parse("dd")(((com.x2dev.sis.model.be ans.SisPerson)field_person.getValue()).getDob())); //$JR_EXPR_ID=27$
<-------------------->
2. Cannot make a static reference to the non-static method parse(String) from the type DateFormat
value = CONCATENATE(((java.lang.String)field_localId.getVa lue()),LEFT(new SimpleDateFormat.parse(((com.x2dev.sis.model.beans .SisPerson)field_person.getValue()).getDob())),Sim pleDateFormat.parse("dd")(((com.x2dev.sis.model.be ans.SisPerson)field_person.getValue()).getDob())); //$JR_EXPR_ID=27$
<-------------------------->
3. Syntax error on token ")", , expected after this token
value = CONCATENATE(((java.lang.String)field_localId.getVa lue()),LEFT(new SimpleDateFormat.parse(((com.x2dev.sis.model.beans .SisPerson)field_person.getValue()).getDob())),Sim pleDateFormat.parse("dd")(((com.x2dev.sis.model.be ans.SisPerson)field_person.getValue()).getDob())); //$JR_EXPR_ID=27$
^
4. SimpleDateFormat.parse cannot be resolved to a type
value = CONCATENATE(((java.lang.String)field_localId.getOl dValue()),LEFT(new SimpleDateFormat.parse(((com.x2dev.sis.model.beans .SisPerson)field_person.getOldValue()).getDob())), SimpleDateFormat.parse("dd")(((com.x2dev.sis.model .beans.SisPerson)field_person.getOldValue()).getDo b())); //$JR_EXPR_ID=27$
<-------------------->
5. Cannot make a static reference to the non-static method parse(String) from the type DateFormat
value = CONCATENATE(((java.lang.String)field_localId.getOl dValue()),LEFT(new SimpleDateFormat.parse(((com.x2dev.sis.model.beans .SisPerson)field_person.getOldValue()).getDob())), SimpleDateFormat.parse("dd")(((com.x2dev.sis.model .beans.SisPerson)field_person.getOldValue()).getDo b())); //$JR_EXPR_ID=27$
<-------------------------->
6. Syntax error on token ")", , expected after this token
value = CONCATENATE(((java.lang.String)field_localId.getOl dValue()),LEFT(new SimpleDateFormat.parse(((com.x2dev.sis.model.beans .SisPerson)field_person.getOldValue()).getDob())), SimpleDateFormat.parse("dd")(((com.x2dev.sis.model .beans.SisPerson)field_person.getOldValue()).getDo b())); //$JR_EXPR_ID=27$
^
7. SimpleDateFormat.parse cannot be resolved to a type
value = CONCATENATE(((java.lang.String)field_localId.getVa lue()),LEFT(new SimpleDateFormat.parse(((com.x2dev.sis.model.beans .SisPerson)field_person.getValue()).getDob())),Sim pleDateFormat.parse("dd")(((com.x2dev.sis.model.be ans.SisPerson)field_person.getValue()).getDob())); //$JR_EXPR_ID=27$
<-------------------->
8. Cannot make a static reference to the non-static method parse(String) from the type DateFormat
value = CONCATENATE(((java.lang.String)field_localId.getVa lue()),LEFT(new SimpleDateFormat.parse(((com.x2dev.sis.model.beans .SisPerson)field_person.getValue()).getDob())),Sim pleDateFormat.parse("dd")(((com.x2dev.sis.model.be ans.SisPerson)field_person.getValue()).getDob())); //$JR_EXPR_ID=27$
<-------------------------->
9. Syntax error on token ")", , expected after this token
value = CONCATENATE(((java.lang.String)field_localId.getVa lue()),LEFT(new SimpleDateFormat.parse(((com.x2dev.sis.model.beans .SisPerson)field_person.getValue()).getDob())),Sim pleDateFormat.parse("dd")(((com.x2dev.sis.model.be ans.SisPerson)field_person.getValue()).getDob())); //$JR_EXPR_ID=27$
^
9 errors[COLOR="Silver"]