title: How to set empty context root for payara micro?
body: <p>my app works with payara server without setting any context root but payara micro is setting default context root as name of my war file. How do I set context root to empty in case ot payara micro ?</p>
  <p>one of the way is to set war name as ROOT.war but with that name i get following error while deploying. I tried putting xerces-2.9.1 jar in --addLibs but doesnt work.</p>
  <pre><code>2020-08-20T21:36:53.110+0200] [] [SEVERE] [] [javax.enterprise.system.tools.deployment.common] [tid: _ThreadID=1 _ThreadName=main] [timeMillis: 1597952213110] [levelValue: 1000] [[
    Exception while invoking class com.sun.enterprise.web.WebApplication start method
  java.lang.Exception: java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: org.apache.catalina.LifecycleException: java.lang.AbstractMethodError
      at com.sun.enterprise.web.WebApplication.start(WebApplication.java:136)
      at org.glassfish.internal.data.EngineRef.start(EngineRef.java:123)
      at org.glassfish.internal.data.ModuleInfo.start(ModuleInfo.java:280)
      at org.glassfish.internal.data.ApplicationInfo.start(ApplicationInfo.java:344)
      at com.sun.enterprise.v3.server.ApplicationLifecycle.initialize(ApplicationLifecycle.java:584)
      at fish.payara.deployment.admin.InitializeAllApplicationsCommand.execute(InitializeAllApplicationsCommand.java:75)
      at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:558)
      at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:554)
      at java.security.AccessController.doPrivileged(Native Method)
      at javax.security.auth.Subject.doAs(Subject.java:360)
      at com.sun.enterprise.v3.admin.CommandRunnerImpl$2.execute(CommandRunnerImpl.java:553)
      at com.sun.enterprise.v3.admin.CommandRunnerImpl$3.run(CommandRunnerImpl.java:584)
      at com.sun.enterprise.v3.admin.CommandRunnerImpl$3.run(CommandRunnerImpl.java:576)
      at java.security.AccessController.doPrivileged(Native Method)
      at javax.security.auth.Subject.doAs(Subject.java:360)
      at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:575)
      at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:1496)
      at com.sun.enterprise.v3.admin.CommandRunnerImpl.access$1300(CommandRunnerImpl.java:120)
      at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1878)
      at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1754)
      at com.sun.enterprise.admin.cli.embeddable.CommandExecutorImpl.executeCommand(CommandExecutorImpl.java:183)
      at com.sun.enterprise.admin.cli.embeddable.CommandExecutorImpl.run(CommandExecutorImpl.java:96)
      at fish.payara.micro.impl.PayaraMicroImpl.bootStrap(PayaraMicroImpl.java:1063)
      at fish.payara.micro.impl.PayaraMicroImpl.create(PayaraMicroImpl.java:211)
      at fish.payara.micro.impl.PayaraMicroImpl.main(PayaraMicroImpl.java:200)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:498)
      at fish.payara.micro.boot.loader.MainMethodRunner.run(MainMethodRunner.java:50)
      at fish.payara.micro.boot.loader.Launcher.launch(Launcher.java:114)
      at fish.payara.micro.boot.loader.Launcher.launch(Launcher.java:73)
      at fish.payara.micro.boot.PayaraMicroLauncher.create(PayaraMicroLauncher.java:87)
      at fish.payara.micro.boot.PayaraMicroLauncher.main(PayaraMicroLauncher.java:71)
      at fish.payara.micro.PayaraMicro.main(PayaraMicro.java:397)
  ]]
  </code></pre>