ClassCastException when evaluate DB Number DType

[bobz28]

Hi,

 

I am using Jasper Report with Hibernate and Spring env. Everything seems to work great excepts that when my hibernate query has a field of NUMBER type (Oracle), the report throws ClassCastException when evaluates the JRField.

 

Here is brief of what I have:

1. Query in the hibernate mapping file(hbm.xml file):

i.e SELECT a, b, c from myTable; (where a and c are VARCHAR2 and b is NUMBER. I named mySelect1).

2. Created a Class (myHQDS) to implement JRDataSource interface.

3. Code in the program:

List report = session.find("mySelect1");Map parameters = new HashMap();parameters.put("Title", "The Report");...Load and compile the reportString[] fields = new String[] { "a", "b", "c"};myHQDS ds = new myHQDS(report, fields);JasperPrint jasperPrint = JasperManager.fillReport(jasperReport, parameters, ds);JasperManager.printReportToPdfFile(jasperPrint, "the-report.pdf");[/code]

4. Error encountered:

net.sf.jasperreports.engine.fill.JRExpressionEvaluationException: Error evaluation exception

   Source text: $F{b}.

...

java.lang.ClassCastException: java.math.BigDecimal

at the-report_12.....evaluate(the-report_12......:201)

net.sf.jasperreports.engine.fill.JREvaluator.evaluate(JREvaluator.java: 186)

 

I changed the filed name in the mapping file as well as the java object from int, Integer to java.lang.Number ...etc, but still I have the error when evaluate this filed. If I commeded this field out, it works perfectly fine. Can some body help???

Thanks in advance,

Bob

[bobz28]

Does anyone have any answer?

[lucianc]

Post your JRXML.

If you're using $F{b} as expression for a text field, make sure you do <textFieldExpression class="java.lang.Number">$F{b}</textFieldExpression>

Regards,

Lucian

[bobz28]

Lucian,

Thanks for your response. Yes I tried to change the data type from Number, int to BigDecimal...etc. But I still the ClassCastException error when evaluate field. Below is the simplyfied version of my JRXML. Thanks-

 

<?xml version="1.0"?>

<!DOCTYPE jasperReport PUBLIC "-//JasperReports//DTD Report Design//EN" "http://jasperreports.sourceforge.net/dtds/jasperreport.dtd">

<jasperReport name="myTemplate">

<parameter name="TITLE" class="java.lang.String"/>

<field name="a" class="java.lang.String"/>
<field name="b" class="java.lang.Number"/>
<field name="c" class="java.lang.String"/>


<detail>
   <band height="40">
     <textField>
       <reportElement x="0" y="0" width="150" height="40"/>
       <textFieldExpression class="java.lang.String">
        <![CDATA[$F{a}]]>
       </textFieldExpression>
     </textField>

     <textField>
       <reportElement x="150" y="0" width="150" height="40"/>
       <textFieldExpression class="java.lang.Number">
        <![CDATA[$F{b}]]>
       </textFieldExpression>
     </textField>

     <textField>
       <reportElement x="300" y="0" width="150" height="40"/>
       <textFieldExpression class="java.lang.String">
        <![CDATA[$F{c}]]>
       </textFieldExpression>
     </textField>
   </band>
</detail>
</jasperReport>

[lucianc]

The JRXML looks fine, assuming that the data source returns a BigDecimal as value for the "b" field.

Create a text field that shows $F{b}.getClass().getName() and see what the output is when you run the report.

Regards,

Lucian

[bobz28]

Hi Lucian,

 

How can I create a text field $F{b}.getClass().getName()? you mean in JRXML file?

Because, as soon as I include the b field in my hibernate query and in my code, I get the error as I posted above.

 

Thanks,

Bob

[lucianc]

Where is this error coming from?  Please post the full exception stacktrace.

[bobz28]

Hi Lucian,

 

My Jasper works is on a diff network so I can't cut and paste it here, but something like this:

 

net.sf.jasperreports.engine.fill.JRExpressionEvaluationException: Error evaluation exception

Source text: $F{b}.

at net.sf.jasperreports.engine.fill.JREvaluator.evaluate(JREvaluator.java: 197)

net.sf.jasperreports.engine.fill.JRCalculator.evaluate(JRCalculator.java: 574)

net.sf.jasperreports.engine.fill.JRCalculator.evaluate(JRCalculator.java: 542)

...

...

net.sf.jasperreports.engine.fill.JRFillTextField.evaluateText(JRFillTextField.java: 368)

Truncated. See log file for complete Starcktrace

java.lang.ClassCastException: java.math.BigDecimal

at the-report_12.....evaluate(the-report_12......:201)

net.sf.jasperreports.engine.fill.JREvaluator.evaluate(JREvaluator.java: 186)

...

net.sf.jasperreports.engine.fill.JRFillElement.evaluateExpression(JRFillElement.java: 835)

Truncated. See log file for complete Starcktrace

 

 

I ran a debugger and found the values for the 3 fields a, b, and c. The a and c fields values are as normal as String results, but the b field is returned as BigDecimal. Is it normal?

 

Thanks again for your help.

Bob

[bobz28]

Lucian,

I ran the debug and got the value for "b" field is BigDecimal. I am expecting a numeric value instead...

Do you have idea, suggestion?

 

Thanks,

Bob

[lucianc]

Could you set the net.sf.jasperreports.compiler.keep.java.file property to true, and check the Java file generated by JR for the report?  Go to line 201 to see how the expression got translated in the file..

Regards,

Lucian

[bobz28]

Hi Lucian,

 

I made the change and re-run...But don't know where to look for the generated Java file...Where should it be?

 

Thanks,

Bob

[bobz28]

Can some body help??? I am stuck...

[lucianc]

Sorry for the long pause.

You can tell the compiler where to keep the generated file via the net.sf.jasperreports.compiler.temp.dir property.

If seeing the generated Java file doesn't yield any clues, the only solution is to prepare a self-contained test case to reproduce the problem.  Otherwise I'm afraid this investigation isn't going to have any finalization.

Regards,

Lucian

[bobz28]

Hi Lucian,

I am using Jaspperreports-3.1.0 and couldn't find the property file in net.sf.jasperreports.compiler.temp.dir directory.

 

Thanks,

Bob

[bobz28]

Lucian,

 

I found a work around for this issue by adding a check for the returned column in question and convert it to Integer...

 

i.e:

====

public Object getFieldValue(JRField field) throws JRException{

Object value = null;

int index = getFieldIndex(field.getName());

if (index !=-1){

//This block is added...

Object[] values = (Object[])currentValue;

if("columnInQuestion".equalsIgnoreCase(field.getName()))

{

Integer myInt = new Integer(values[index].toString());

value = myInt;

}else{

value = values[index];

}

}

return value;

}