When I tried to host the plantUML picowebserver in Docker having this error

Question

Error java.lang.NoClassDefFoundError: Could not initialize class net.sourceforge.plantuml.ugraphic.UFont
java.lang.NoClassDefFoundError: Could not initialize class net.sourceforge.plantuml.ugraphic.UFont
        at net.sourceforge.plantuml.creole.legacy.CreoleParser.checkColor(CreoleParser.java:177)
        at net.sourceforge.plantuml.cucadiagram.Display.createFoo(Display.java:174)
        at net.sourceforge.plantuml.command.BlocLines.toDisplay(BlocLines.java:103)
        at net.sourceforge.plantuml.command.CommandMultilinesLegend.executeNow(CommandMultilinesLegend.java:84)
        at net.sourceforge.plantuml.command.CommandMultilinesLegend.executeNow(CommandMultilinesLegend.java:50)
        at net.sourceforge.plantuml.command.CommandMultilines2.execute(CommandMultilines2.java:111)
        at net.sourceforge.plantuml.command.ProtectedCommand.execute(ProtectedCommand.java:55)
        at net.sourceforge.plantuml.AbstractPSystem.executeCommand(AbstractPSystem.java:158)
        at net.sourceforge.plantuml.command.PSystemCommandFactory.executeFewLines(PSystemCommandFactory.java:125)
        at net.sourceforge.plantuml.command.PSystemCommandFactory.createSystem(PSystemCommandFactory.java:108)
        at net.sourceforge.plantuml.PSystemBuilder.createPSystem(PSystemBuilder.java:137)
        at net.sourceforge.plantuml.BlockUml.getDiagram(BlockUml.java:179)
        at net.sourceforge.plantuml.picoweb.PicoWebServer.handleGET(PicoWebServer.java:229)
        at net.sourceforge.plantuml.picoweb.PicoWebServer.run(PicoWebServer.java:121)
        at java.lang.Thread.run(Thread.java:748)

Answer 1

Sound like your server does not have graphical capabilities.

See https://plantuml.com/en/faq#239d64f675c3e515

Tell us if it helps!