Charts not working on OpenJDK / Zulu JDK

[kaikreuzer]

Using Zulu JDK / OpenJDK, using the chart servlet results in

java.lang.NullPointerException
	at sun.awt.FontConfiguration.getVersion(FontConfiguration.java:1264)[:1.8.0_112]
	at sun.awt.FontConfiguration.readFontConfigFile(FontConfiguration.java:219)[:1.8.0_112]
	at sun.awt.FontConfiguration.init(FontConfiguration.java:107)[:1.8.0_112]
	at sun.awt.X11FontManager.createFontConfiguration(X11FontManager.java:774)[:1.8.0_112]
	at sun.font.SunFontManager$2.run(SunFontManager.java:431)[:1.8.0_112]
	at java.security.AccessController.doPrivileged(Native Method)[:1.8.0_112]
	at sun.font.SunFontManager.<init>(SunFontManager.java:376)[:1.8.0_112]
	at sun.awt.FcFontManager.<init>(FcFontManager.java:35)[:1.8.0_112]
	at sun.awt.X11FontManager.<init>(X11FontManager.java:57)[:1.8.0_112]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)[:1.8.0_112]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)[:1.8.0_112]
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)[:1.8.0_112]
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)[:1.8.0_112]
	at java.lang.Class.newInstance(Class.java:442)[:1.8.0_112]
	at sun.font.FontManagerFactory$1.run(FontManagerFactory.java:83)[:1.8.0_112]
	at java.security.AccessController.doPrivileged(Native Method)[:1.8.0_112]
	at sun.font.FontManagerFactory.getInstance(FontManagerFactory.java:74)[:1.8.0_112]
	at java.awt.Font.getFont2D(Font.java:491)[:1.8.0_112]
	at java.awt.Font.defaultLineMetrics(Font.java:2176)[:1.8.0_112]
	at java.awt.Font.getLineMetrics(Font.java:2283)[:1.8.0_112]
	at java.awt.font.TextLayout.fastInit(TextLayout.java:598)[:1.8.0_112]
	at java.awt.font.TextLayout.<init>(TextLayout.java:393)[:1.8.0_112]
	at com.xeiam.xchart.internal.chartpart.Axis.getSizeHint(Axis.java:138)[136:org.eclipse.smarthome.ui:0.9.0.b4]
	at com.xeiam.xchart.internal.chartpart.Axis.paint(Axis.java:169)[136:org.eclipse.smarthome.ui:0.9.0.b4]
	at com.xeiam.xchart.internal.chartpart.AxisPair.paint(AxisPair.java:130)[136:org.eclipse.smarthome.ui:0.9.0.b4]
	at com.xeiam.xchart.internal.chartpart.ChartPainter.paint(ChartPainter.java:94)[136:org.eclipse.smarthome.ui:0.9.0.b4]
	at com.xeiam.xchart.Chart.paint(Chart.java:105)[136:org.eclipse.smarthome.ui:0.9.0.b4]
	at org.eclipse.smarthome.ui.internal.chart.DefaultChartProvider.createChart(DefaultChartProvider.java:225)[136:org.eclipse.smarthome.ui:0.9.0.b4]
	at org.eclipse.smarthome.ui.internal.chart.ChartServlet.doGet(ChartServlet.java:190)[136:org.eclipse.smarthome.ui:0.9.0.b4]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)[19:javax.servlet-api:3.1.0]

There are similar reports on the web.
I already tried

apt-get install libfontconfig1 fontconfig ttf-dejavu

but without effect :-(

[watou]

Another report with a similar stacktrace.

[kaikreuzer]

I saw that one, but I didn't find their referenced commit that fixed the issue for them.

[watou]

referenced commit that fixed the issue for them.

Yes, it would be helpful if they referenced the commits that fix issues. ;-)

This might be it, basically installing some fonts so OpenJDK has fonts.

[kaikreuzer]

Ok, I found the solution: As we are running 32-bit JVM, we have to install

apt-get install fontconfig:armhf

on the Pine64 and all is good!

[openhab-bot]

This issue has been mentioned on openHAB Community. There might be relevant details there:

https://community.openhab.org/t/npe-in-fontmanagerfactory-when-opening-charts/117077/1