RE: NullPointerException when invoking JUnit using Groovy Ant under Tomcat

Just wanted to let the Groovy User community know that my colleague, John 
Lewis, solved this problem. 

The issue was not Groovy, but rather the way I was setting system properties to 
pass into Junit. Here was the method I was using to set system properties - I 
got the idea from Googling around online: 

    static public void setSysProperties(String key1, String val1, 
                                        String key2, String val2, 
                                        String key3, String val3 )
    {
        // Read current properties from the System environment
        Properties p = System.getProperties();
        p.setProperty(key1, val1);
        p.setProperty(key2, val2);
        p.setProperty(key3, val3);
        
        // set the system properties
        System.setProperties(p);
    }

John changed the line:

Properties p = new Properties(System.getProperties())

To:

Properties p = System.getProperties()

The Properies constructor that was used takes a properties object as a 
parameter.  That parameter sets the defaults but does not actually add those as 
properties.  Later, Ant code (not Groovy) enumerates over the system properties 
and adds more properties similar to what I was trying to do.  Because all of 
the "old" system properties are just defaults, they do not show up in the 
enumeration.  So, they are not passed on.

I guess this could be viewed as an Ant deficiency that was made visible by what 
I was doing using the Properties constructor. 

Here is the Ant code:

             sys = System.getProperties();
             Properties p = new Properties();
             for (Enumeration e = sys.keys(); e.hasMoreElements();) {
                 Object o = e.nextElement();
                 p.put(o, sys.get(o));
             }

They should enumerate with sys.propertyNames() instead.  They would get the 
defaults if they did that.

Regards,
Trevor Butler


-----Original Message-----
From: Trevor Butler [mailto:Trevor.Butler-LVvIjLR0h5w@xxxxxxxxxxxxxxxx] 
Sent: Friday, October 22, 2004 4:39 PM
To: user-i9PBDF1N6cxnkHa44VUL00B+6BGkLq7r@xxxxxxxxxxxxxxxx
Subject: [groovy-user] NullPointerException when invoking JUnit using Groovy 
Ant under Tomcat


The subject line is a mouthful! Here is what I am doing:

I needed a means to invoke JUnit within a web container within the same jvm, so 
that I can pass system properties to the Junit test.  Someone in my department 
suggested using Groovy's Ant integration to invoke JUnit, which I have done. 
When groovy invokes Junit, I get a nasty Exception. Here is a snippet of the 
Tomcat console: 

    [junit] Running com.mycompany.MyTest
    [junit] Tests run: 1, Failures: 0, Errors: 1, Time elapsed: 0 secnull 
java.lang.NullPointerException
        at java.io.Writer.write(Writer.java:126)
        at 
org.apache.tools.ant.util.DOMElementWriter.write(DOMElementWriter.java:113)
        at 
org.apache.tools.ant.taskdefs.optional.junit.XMLJUnitResultFormatter.endTestSuite(XMLJUnitResultFormatter.java:135)
        at 
org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.fireEndTestSuite(JUnitTestRunner.java:440)
        at 
org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.run(JUnitTestRunner.java:313)
        at 
org.apache.tools.ant.taskdefs.optional.junit.JUnitTask.executeInVM(JUnitTask.java:954)
        at 
org.apache.tools.ant.taskdefs.optional.junit.JUnitTask.execute(JUnitTask.java:626)
        at 
org.apache.tools.ant.taskdefs.optional.junit.JUnitTask.execute(JUnitTask.java:600)
        at org.apache.tools.ant.Task.perform(Task.java:364)
        at groovy.util.AntBuilder.nodeCompleted(AntBuilder.java:115)
        at groovy.util.BuilderSupport.doInvokeMethod(BuilderSupport.java:160)
        at groovy.util.BuilderSupport.invokeMethod(BuilderSupport.java:85)
        at org.codehaus.groovy.runtime.Invoker.invokeMethod(Invoker.java:130)
        at 
org.codehaus.groovy.runtime.InvokerHelper.invokeMethod(InvokerHelper.java:106)
        at com.sas.junit.JUnitInvoker.runJUnit(C:\JUnitInvoker.groovy:29)
        at 
gjdk.com.sas.junit.JUnitInvoker_GroovyReflector.invoke(JUnitInvoker_GroovyReflector.java)
        at groovy.lang.MetaMethod.invoke(MetaMethod.java:110)
        at groovy.lang.MetaClass.doMethodInvoke(MetaClass.java:1398)
        at groovy.lang.MetaClass.invokeMethod(MetaClass.java:319)
        at 
gjdk.groovy.lang.MetaClass_GroovyReflector.invoke(MetaClass_GroovyReflector.java)
        at groovy.lang.MetaMethod.invoke(MetaMethod.java:110)
        at groovy.lang.MetaClass.doMethodInvoke(MetaClass.java:1398)
        at groovy.lang.MetaClass.invokeMethod(MetaClass.java:319)
        at org.codehaus.groovy.runtime.Invoker.invokeMethod(Invoker.java:143)
        at 
org.codehaus.groovy.runtime.InvokerHelper.invokeMethod(InvokerHelper.java:106)
        at com.mycompany.junit.JUnitInvoker.invokeMethod(C:\JUnitInvoker.groovy)
        at com.mycompany.junit.caller.InvokerCaller.callJUnitInvoker(Unknown 
Source)
        at 
com.mycompany.testserver.handler.EmpirixHandler.handleRequest(EmpirixHandler.java:150)
        at 
com.mycompany.testserver.RemoteControlTestService.handleRequest(RemoteControlTestService.java:201)
        at 
com.mycompany.testserver.RemoteControlTestService.doPost(RemoteControlTestService.java:62)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
        at 
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
        at 
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
        at 
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
        at 
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at 
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at 
org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
        at 
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
        at 
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at 
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at 
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
        at 
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at 
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
        at 
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
        at 
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at 
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at 
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at 
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
        at 
org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
        at 
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
        at 
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
        at 
org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
        at 
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
        at java.lang.Thread.run(Thread.java:534)


>From the following post, it appears that the problem is caused by the Junit 
>testcase name being null:
http://www.diasparsoftware.com/weblog/archives/00000004.html

Well, I think the name is being passed in by groovy (or Ant), when it creates 
the Junit testcase (using the TestCase constructor). 

Does anyone know if this is a Groovy bug, or if perhaps it can be fixed by 
configuration changes, etc?  I have been trying to figure it out for over two 
days.

Thanks,
Trevor