net.sf.jasperreports.engine.util.JdkGlyphFixTextMeasurer Maven / Gradle / Ivy
/*
* JasperReports - Free Java Reporting Library.
* Copyright (C) 2001 - 2014 TIBCO Software Inc. All rights reserved.
* http://www.jaspersoft.com
*
* Unless you have purchased a commercial license agreement from Jaspersoft,
* the following license terms apply:
*
* This program is part of JasperReports.
*
* JasperReports is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* JasperReports is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with JasperReports. If not, see
* The workaround consists of simply reattempting the text measuring when
* a java.lang.NullPointerException is thrown from
* sun.font.GlyphLayout.
*
*
* @author Lucian Chirita ([email protected])
* @see JdkGlyphFixTextMeasurerFactory
*/
public class JdkGlyphFixTextMeasurer extends TextMeasurer
{
private static final Log log = LogFactory.getLog(JdkGlyphFixTextMeasurer.class);
protected static final String JDK_EXCEPTION_CLASS_PREFIX = "sun.font.GlyphLayout";
/**
* The default attempt count.
*/
public static final int DEFAULT_ATTEMPTS = 20;
/**
* The default between attempts sleep time.
*/
public static final int DEFAULT_ATTEMPT_SLEEP = 0;
/**
* A property that specifies the number of times the measurer should attempt
* to measure a single text element before giving up.
*
* The default value is 20.
*
* @see #DEFAULT_ATTEMPTS
*/
public static final String PROPERTY_ATTEMPTS = JRPropertiesUtil.PROPERTY_PREFIX
+ "jdk.glyph.fix.text.measurer.attempts";
/**
* A property that specifies the number of milliseconds to sleep between
* measuring reattempts.
*
* The default value is 0, which means that the measurer will not pause
* between reattempts.
*
* @see #DEFAULT_ATTEMPT_SLEEP
*/
public static final String PROPERTY_ATTEMPT_SLEEP = JRPropertiesUtil.PROPERTY_PREFIX
+ "jdk.glyph.fix.text.measurer.sleep";
/**
* Whether java.lang.NullPointer exceptions with empty stacktraces
* should be caught.
*
* This is useful when running on a Sun server JVM (java -server), which might omit
* exception stacktraces in some cases.
*/
public static final String PROPERTY_CATCH_EMPTY_STACKTRACE = JRPropertiesUtil.PROPERTY_PREFIX
+ "jdk.glyph.fix.text.measurer.catch.empty.stakctrace";
private final int attempts;
private final int sleep;
private final boolean catchEmptyStacktrace;
/**
* Create a text measurer for a text element.
*
* @param textElement the text element
*/
public JdkGlyphFixTextMeasurer(JasperReportsContext jasperReportsContext, JRCommonText textElement)
{
super(jasperReportsContext, textElement);
attempts = JRPropertiesUtil.getInstance(jasperReportsContext).getIntegerProperty(PROPERTY_ATTEMPTS, DEFAULT_ATTEMPTS);
sleep = JRPropertiesUtil.getInstance(jasperReportsContext).getIntegerProperty(PROPERTY_ATTEMPT_SLEEP, DEFAULT_ATTEMPT_SLEEP);
catchEmptyStacktrace = JRPropertiesUtil.getInstance(jasperReportsContext).getBooleanProperty(PROPERTY_CATCH_EMPTY_STACKTRACE);
}
/**
* @deprecated Replaced by {@link #JdkGlyphFixTextMeasurer(JasperReportsContext, JRCommonText)}.
*/
public JdkGlyphFixTextMeasurer(JRCommonText textElement)
{
this(DefaultJasperReportsContext.getInstance(), textElement);
}
/**
* Calls {@link TextMeasurer#measure(JRStyledText, int, int, boolean) super.measure}, catches
* sun.font.GlyphLayout NPEs and reattempts the call.
*/
public JRMeasuredText measure(JRStyledText styledText, int remainingTextStart, int availableStretchHeight, boolean canOverflow)
{
int count = 0;
do
{
try
{
++count;
return super.measure(styledText, remainingTextStart, availableStretchHeight, canOverflow);
}
catch (NullPointerException e) //NOPMD
{
if (isJdkGlyphError(e))
{
if (count >= attempts)
{
log.error("JDK Glyph exception caught " + attempts + " times, giving up attempts");
throw e;
}
}
else
{
throw e;
}
if (log.isDebugEnabled())
{
log.debug("Caught JDK Glyph exception " + e + " at attempt #" + count);
}
if (sleep > 0)
{
try
{
Thread.sleep(sleep);
}
catch (InterruptedException ie)
{
throw new JRRuntimeException(ie); //NOPMD
}
}
}
}
while(true);
}
protected boolean isJdkGlyphError(NullPointerException e)
{
StackTraceElement[] stackTrace = e.getStackTrace();
if (stackTrace.length == 0)
{
if (log.isDebugEnabled())
{
log.debug("Caught exception with no stacktrace; "
+ (catchEmptyStacktrace ? "" : "not ") + "treating as JDK Glyph exception");
}
return catchEmptyStacktrace;
}
StackTraceElement top = stackTrace[0];
return top.getClassName().startsWith(JDK_EXCEPTION_CLASS_PREFIX);
}
}