Occasional NullPointerException with Scheduled Reports

Job: 422797 (ID: 2865)
Report unit: /SampleName
Quartz Job: ReportJobs.job_2865
Quartz Trigger: ReportJobs.trigger_2863_0
Exceptions:

An error occurred while executing the report.
java.lang.NullPointerException
at sun.font.GlyphLayout$EngineRecord.init(GlyphLayout.java:565)
at sun.font.GlyphLayout.nextEngineRecord(GlyphLayout.java:439)
at sun.font.GlyphLayout.layout(GlyphLayout.java:362)
at sun.font.ExtendedTextSourceLabel.createGV(ExtendedTextSourceLabel.java:267)
at sun.font.ExtendedTextSourceLabel.getGV(ExtendedTextSourceLabel.java:252)
at sun.font.ExtendedTextSourceLabel.createLogicalBounds(ExtendedTextSourceLabel.java:163)
at sun.font.ExtendedTextSourceLabel.getAdvance(ExtendedTextSourceLabel.java:85)
at java.awt.font.TextLine.init(TextLine.java:245)
at java.awt.font.TextLine.(TextLine.java:99)
at java.awt.font.TextMeasurer.makeTextLineOnRange(TextMeasurer.java:467)
at java.awt.font.TextMeasurer.getLayout(TextMeasurer.java:598)
at java.awt.font.LineBreakMeasurer.nextLayout(LineBreakMeasurer.java:427)
at java.awt.font.LineBreakMeasurer.nextLayout(LineBreakMeasurer.java:395)
at net.sf.jasperreports.engine.fill.TextMeasurer.renderNextLine(TextMeasurer.java:505)
at net.sf.jasperreports.engine.fill.TextMeasurer.renderParagraph(TextMeasurer.java:338)
at net.sf.jasperreports.engine.fill.TextMeasurer.measure(TextMeasurer.java:291)
at net.sf.jasperreports.engine.fill.JRFillTextElement.chopTextElement(JRFillTextElement.java:987)
at net.sf.jasperreports.engine.fill.JRFillTextField.prepare(JRFillTextField.java:528)
at net.sf.jasperreports.engine.fill.JRFillElementContainer.prepareElements(JRFillElementContainer.java:344)
at net.sf.jasperreports.engine.fill.JRFillFrame.prepare(JRFillFrame.java:215)
at net.sf.jasperreports.engine.fill.JRFillElementContainer.prepareElements(JRFillElementContainer.java:344)
at net.sf.jasperreports.engine.fill.JRFillBand.fill(JRFillBand.java:346)
at net.sf.jasperreports.engine.fill.JRFillBand.fill(JRFillBand.java:305)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillColumnBand(JRVerticalFiller.java:1382)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillDetail(JRVerticalFiller.java:692)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReportContent(JRVerticalFiller.java:275)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:117)
at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:879)
at net.sf.jasperreports.engine.fill.JRFiller.fillReport(JRFiller.java:123)
at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:420)
at com.jaspersoft.jasperserver.api.engine.jasperreports.service.impl.EngineServiceImpl.fillReport(EngineServiceImpl.java:661)
at com.jaspersoft.jasperserver.api.engine.jasperreports.service.impl.EngineServiceImpl.fillReport(EngineServiceImpl.java:356)
at com.jaspersoft.jasperserver.api.engine.jasperreports.service.impl.EngineServiceImpl.executeReport(EngineServiceImpl.java:788)
at com.jaspersoft.jasperserver.api.engine.jasperreports.domain.impl.ReportUnitRequest.execute(ReportUnitRequest.java:60)
at com.jaspersoft.jasperserver.api.engine.jasperreports.service.impl.EngineServiceImpl.execute(EngineServiceImpl.java:288)
at com.jaspersoft.jasperserver.api.engine.scheduling.quartz.ReportExecutionJob.executeReport(ReportExecutionJob.java:441)
at com.jaspersoft.ji.report.options.engine.ReportOptionsExecutionJob.executeReport(ReportOptionsExecutionJob.java:103)
at com.jaspersoft.jasperserver.api.engine.scheduling.quartz.ReportExecutionJob.executeAndSendReport(ReportExecutionJob.java:369)
at com.jaspersoft.jasperserver.api.engine.scheduling.quartz.ReportExecutionJob.execute(ReportExecutionJob.java:188)
at org.quartz.core.JobRunShell.run(JobRunShell.java:195)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:520)

Cause

This issue appears to be caused by a multithreading bug in the Sun AWT code.

See the following: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6367148

The issue appears most commonly in very active multi-processor environments.

Resolution

Jaspersoft has implemented a workaround to the Sun AWT defect by reattempting the failed action. The fix consists of a custom text measurer that catches NPEs thrown by the JDK GlyphLayout class, and reattempts to measure the text field. The fix is external to JasperReports (note still that JR >= 2.0.3 is required).

You may need to add the following line to jasperreports.properties file under WEB-INF/classes sub directory to make the code work:

net.sf.jasperreports.text.measurer.factory=net.sf.jasperreports.engine.util.JdkGlyphFixTextMeasurerFactory

The custom text measurer is itself configurable via the following JR properties:

1. net.sf.jasperreports.jdk.glyph.fix.text.measurer.attempts - gives the number of attempts to measure a text before giving up; the default value is 20 (which should be enough given that my test never went beyond 2 attempts).
2. net.sf.jasperreports.jdk.glyph.fix.text.measurer.sleep - the number of milliseconds to sleep between attempts; the default value is 0, i.e. no sleep (according to my tests, no sleep is actually required).

3. net.sf.jasperreports.jdk.glyph.fix.text.measurer.catch.empty.stakctrace - specifies whether NPEs with no stacktrace should be considered as GlyphLayout exceptions or not.

   This last property is meant to address the fact that the Sun server VM might omit the stacktrace from NPEs thrown from GlyphLayout, which makes it impossible to determine whether en exception was actually thrown from GlyphLayout or not.

If using a server VM (java -server), this property should be set to true, or the -XX:-OmitStackTraceInFastThrow VM options should be used to force the VM to always set exception stacktraces (more details at http://java.sun.com/j2se/1.5.0/relnotes.html#hotspot).