Some implementations may use null to represent the bootstrap classloader. This method will return null in such implementations if this class was loaded by the bootstrap class loader.

> java.lang.NullPointerException
> at java.lang.NullPointerException
> at at ch.qos.logback.classic.util.EnvUtil.isGroovyAvailable(EnvUtil.java:25)
> at at ch.qos.logback.classic.joran.action.ConfigurationAction.begin(ConfigurationAction.java:59)
> at at ch.qos.logback.core.joran.spi.Interpreter.callBeginAction(Interpreter.java:276)
> at at ch.qos.logback.core.joran.spi.Interpreter.startElement(Interpreter.java:148)
> at at ch.qos.logback.core.joran.spi.Interpreter.startElement(Interpreter.java:130)
> at at ch.qos.logback.core.joran.spi.EventPlayer.play(EventPlayer.java:50)
> at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:157)
> at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:143)
> at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:106)
> at at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:56)
> at at ch.qos.logback.classic.util.ContextInitializer.configureByResource(ContextInitializer.java:75)
> at at ch.qos.logback.classic.util.ContextInitializer.autoConfig(ContextInitializer.java:148)
> at at org.slf4j.impl.StaticLoggerBinder.init(StaticLoggerBinder.java:85)
> at at org.slf4j.impl.StaticLoggerBinder.<clinit>(StaticLoggerBinder.java:55)
> at at org.slf4j.LoggerFactory.bind(LoggerFactory.java:128)
> at at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:107)
> at at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:295)
> at at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:269)
> at at org.slf4j.bridge.SLF4JBridgeHandler.getSLF4JLogger(SLF4JBridgeHandler.java:204)
> at at org.slf4j.bridge.SLF4JBridgeHandler.publish(SLF4JBridgeHandler.java:291)
> at at java.util.logging.Logger.log(Logger.java:565)
> at at java.util.logging.Logger.doLog(Logger.java:586)
> at at java.util.logging.Logger.logp(Logger.java:755)
> at at org.glassfish.embeddable.GlassFishRuntime.getRuntimeBuilder(GlassFishRuntime.java:181)
> at at org.glassfish.embeddable.GlassFishRuntime._bootstrap(GlassFishRuntime.java:156)
> at at org.glassfish.embeddable.GlassFishRuntime.bootstrap(GlassFishRuntime.java:110)
> at at com.sun.enterprise.glassfish.bootstrap.GlassFishMain$Launcher.launch(GlassFishMain.java:112)
> at at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
> at at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at at java.lang.reflect.Method.invoke(Method.java:601)
> at at com.sun.enterprise.glassfish.bootstrap.GlassFishMain.main(GlassFishMain.java:97)
> at at com.sun.enterprise.glassfish.bootstrap.ASMain.main(ASMain.java:55)