Why is NullPointer Exception thrown in isSplitTypePreventInhibited when contents of table cell overflow to next page? - nullpointerexception

Question

Issue
In a Jasperreport, if the content of table detail cell or header cell is large to not fit in one page, a runtime NullPointer exception is thrown. This behavior is observed in both Jasperreports Studio as well as Jasperreports Server.
Version
6.6 and 6.7
JRXML
For simplicity, empty dataset is used. Important thing here is that the Text
field needs to have its Stretch With Overflow property set to True and large amount of data needs to be displayed which will force the table cell to grow beyond the page height.
<?xml version="1.0" encoding="UTF-8"?>
<!-- Created with Jaspersoft Studio version 6.6.0.final using JasperReports Library version 6.6.0 -->
<jasperReport xmlns="http://jasperreports.sourceforge.net/jasperreports" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports http://jasperreports.sourceforge.net/xsd/jasperreport.xsd" name="Table_Based" pageWidth="842" pageHeight="595" orientation="Landscape" whenNoDataType="AllSectionsNoDetail" columnWidth="802" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="66519d71-4f27-4833-9a1d-c9b72e811f0c">
<property name="template.engine" value="tabular_template"/>
<property name="com.jaspersoft.studio.data.sql.tables" value=""/>
<property name="com.jaspersoft.studio.data.defaultdataadapter" value="Sample DB"/>
<style name="Title" fontName="Times New Roman" fontSize="50" isBold="true"/>
<style name="SubTitle" forecolor="#736343" fontName="Arial" fontSize="18"/>
<style name="Column header" forecolor="#666666" fontName="Arial" fontSize="12" isBold="true"/>
<style name="Row" mode="Transparent">
<conditionalStyle>
<conditionExpression><![CDATA[$V{REPORT_COUNT}%2 == 0]]></conditionExpression>
<style backcolor="#E6DAC3"/>
</conditionalStyle>
</style>
<style name="Table">
<box>
<pen lineWidth="1.0" lineColor="#000000"/>
<topPen lineWidth="1.0" lineColor="#000000"/>
<leftPen lineWidth="1.0" lineColor="#000000"/>
<bottomPen lineWidth="1.0" lineColor="#000000"/>
<rightPen lineWidth="1.0" lineColor="#000000"/>
</box>
</style>
<style name="Table_TH" mode="Opaque" backcolor="#F0F8FF">
<box>
<pen lineWidth="0.5" lineColor="#000000"/>
<topPen lineWidth="0.5" lineColor="#000000"/>
<leftPen lineWidth="0.5" lineColor="#000000"/>
<bottomPen lineWidth="0.5" lineColor="#000000"/>
<rightPen lineWidth="0.5" lineColor="#000000"/>
</box>
</style>
<style name="Table_CH" mode="Opaque" backcolor="#BFE1FF">
<box>
<pen lineWidth="0.5" lineColor="#000000"/>
<topPen lineWidth="0.5" lineColor="#000000"/>
<leftPen lineWidth="0.5" lineColor="#000000"/>
<bottomPen lineWidth="0.5" lineColor="#000000"/>
<rightPen lineWidth="0.5" lineColor="#000000"/>
</box>
</style>
<style name="Table_TD" mode="Opaque" backcolor="#FFFFFF">
<box>
<pen lineWidth="0.5" lineColor="#000000"/>
<topPen lineWidth="0.5" lineColor="#000000"/>
<leftPen lineWidth="0.5" lineColor="#000000"/>
<bottomPen lineWidth="0.5" lineColor="#000000"/>
<rightPen lineWidth="0.5" lineColor="#000000"/>
</box>
</style>
<subDataset name="tableDataset" uuid="bcc32bbf-2279-43e0-8149-66ee3e913b5e">
<property name="com.jaspersoft.studio.data.defaultdataadapter" value="Sample DB"/>
<queryString language="SQL">
<![CDATA[]]>
</queryString>
</subDataset>
<subDataset name="Dataset1" uuid="13d74fad-eb9b-446f-a81d-55b8cf6ea0db">
<queryString>
<![CDATA[]]>
</queryString>
</subDataset>
<queryString>
<![CDATA[]]>
</queryString>
<title>
<band height="113" splitType="Stretch">
<staticText>
<reportElement style="Title" x="270" y="0" width="263" height="62" uuid="a080d2ca-6207-4d8e-87c9-d3b61fb495a9"/>
<textElement verticalAlignment="Middle"/>
<text><![CDATA[Report Title]]></text>
</staticText>
<staticText>
<reportElement style="SubTitle" x="303" y="62" width="196" height="22" uuid="0d849401-f944-4163-9df0-f69408a0618a"/>
<textElement>
<font fontName="Times New Roman"/>
</textElement>
<text><![CDATA[Report SubTitle]]></text>
</staticText>
</band>
</title>
<summary>
<band height="112" splitType="Stretch">
<property name="local_mesure_unitheight" value="pixel"/>
<property name="com.jaspersoft.studio.layout" value="com.jaspersoft.studio.editor.layout.HorizontalRowLayout"/>
<componentElement>
<reportElement stretchType="ElementGroupHeight" x="0" y="0" width="802" height="112" isPrintWhenDetailOverflows="true" uuid="f3767496-0434-4f42-862b-5839d580e423">
<property name="com.jaspersoft.studio.layout" value="com.jaspersoft.studio.editor.layout.HorizontalRowLayout"/>
<property name="com.jaspersoft.studio.table.style.table_header" value="Table_TH"/>
<property name="com.jaspersoft.studio.table.style.column_header" value="Table_CH"/>
<property name="com.jaspersoft.studio.table.style.detail" value="Table_TD"/>
</reportElement>
<jr:table xmlns:jr="http://jasperreports.sourceforge.net/jasperreports/components" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports/components http://jasperreports.sourceforge.net/xsd/components.xsd" whenNoDataType="AllSectionsNoDetail">
<datasetRun subDataset="Dataset1" uuid="e2733267-966b-4b9b-924a-4bbec63e6b35">
<dataSourceExpression><![CDATA[new net.sf.jasperreports.engine.JREmptyDataSource()]]></dataSourceExpression>
</datasetRun>
<jr:column width="200" uuid="a3e3c62f-3558-42a1-a701-ad31853970a9">
<property name="com.jaspersoft.studio.components.table.model.column.name" value="Column1"/>
<jr:columnHeader style="Table_CH" height="30" rowSpan="1">
<staticText>
<reportElement x="0" y="0" width="200" height="30" uuid="56f1cfe1-76be-4cd4-a4ba-5fe3e56b1a2e"/>
<textElement>
<font size="20"/>
</textElement>
<text><![CDATA[Number]]></text>
</staticText>
</jr:columnHeader>
<jr:detailCell style="Table_TD" height="40" rowSpan="1">
<textField isStretchWithOverflow="true">
<reportElement positionType="Float" stretchType="ElementGroupHeight" x="0" y="0" width="200" height="40" uuid="bdcc75f5-e9d8-4013-80e7-d22b346d694b"/>
<textFieldExpression><![CDATA[$V{REPORT_COUNT}]]></textFieldExpression>
</textField>
</jr:detailCell>
</jr:column>
<jr:column width="300" uuid="e2eaa014-ebfd-4795-b752-476ca2fa8f0b">
<property name="com.jaspersoft.studio.components.table.model.column.name" value="Column2"/>
<jr:columnHeader style="Table_CH" height="30" rowSpan="1">
<staticText>
<reportElement x="0" y="0" width="300" height="30" uuid="5d807608-f7ce-4e00-a3e5-5b29bb3228a7"/>
<textElement>
<font size="20"/>
</textElement>
<text><![CDATA[Text]]></text>
</staticText>
</jr:columnHeader>
<jr:detailCell style="Table_TD" height="40">
<property name="com.jaspersoft.studio.layout" value="com.jaspersoft.studio.editor.layout.HorizontalRowLayout"/>
<textField isStretchWithOverflow="true" isBlankWhenNull="false">
<reportElement positionType="Float" stretchType="ElementGroupHeight" x="0" y="0" width="300" height="40" isPrintWhenDetailOverflows="true" uuid="e7d6d343-cd79-4293-8ccd-0b8af33ea962"/>
<textElement>
<paragraph lineSpacing="1_1_2"/>
</textElement>
<textFieldExpression><![CDATA[UPPER("qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm qwertyuiopasdfghjklzxcvbnm")]]></textFieldExpression>
</textField>
</jr:detailCell>
</jr:column>
</jr:table>
</componentElement>
</band>
</summary>
Exception
net.sf.jasperreports.engine.JRException: java.lang.NullPointerException
at com.jaspersoft.studio.editor.preview.view.control.ReportController.fillReport(ReportController.java:536)
at com.jaspersoft.studio.editor.preview.view.control.ReportController.access$17(ReportController.java:511)
at com.jaspersoft.studio.editor.preview.view.control.ReportController$1.run(ReportController.java:429)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:56)
Caused by: java.lang.NullPointerException
at net.sf.jasperreports.engine.fill.FillerSubreportParent.isSplitTypePreventInhibited(FillerSubreportParent.java:116)
at net.sf.jasperreports.engine.fill.JRFillBand.isSplitTypePreventInhibited(JRFillBand.java:633)
at net.sf.jasperreports.engine.fill.JRFillBand.isSplitTypePreventInhibited(JRFillBand.java:612)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillColumnBand(JRVerticalFiller.java:2589)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillDetail(JRVerticalFiller.java:813)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReportStart(JRVerticalFiller.java:264)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:110)
at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:615)
at net.sf.jasperreports.engine.fill.BaseReportFiller.fill(BaseReportFiller.java:432)
at net.sf.jasperreports.engine.fill.JRFillSubreport.fillSubreport(JRFillSubreport.java:818)
at net.sf.jasperreports.engine.fill.JRSubreportRunnable.run(JRSubreportRunnable.java:61)
at net.sf.jasperreports.engine.fill.AbstractThreadSubreportRunner.run(AbstractThreadSubreportRunner.java:221)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)

Answer 1

This is a bug starting probably from version 6.5.1 but should be fixed in version 6.7
The bug report is https://community.jaspersoft.com/jasperreports-library/issues/10451
I tested your report in JasperSoftStudio v 6.6 and I can confirm the bug, however compiling your report with Jasper Reports lib v 6.7 in java using the following code.
JasperReport report = JasperCompileManager.compileReport("pathTo.jrxml");
JasperPrint jasperPrint = JasperFillManager.fillReport(report, new HashMap<String, Object>(), new JREmptyDataSource(1));
JRPdfExporter exporter = new JRPdfExporter();
exporter.setExporterInput(new SimpleExporterInput(jasperPrint));
exporter.setExporterOutput(new SimpleOutputStreamExporterOutput("pdf/SplitTest.pdf"));
SimplePdfExporterConfiguration configuration = new SimplePdfExporterConfiguration();
exporter.setConfiguration(configuration);
exporter.exportReport();
The bug can not be confirmed
Conclusion, this bug seems solved in version 6.7, make sure to do the correct test using version 6.7 or use a version prior to 6.5.1