Jenkins 失败: Cannot invoke method tokenize() on null object

错误：

java.lang.NullPointerException: Cannot invoke method tokenize() on null object
    at org.codehaus.groovy.runtime.NullObject.invokeMethod(NullObject.java:91)
    at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:48)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
    at org.codehaus.groovy.runtime.callsite.NullCallSite.call(NullCallSite.java:35)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
    at org.kohsuke.groovy.sandbox.impl.Checker$1.call(Checker.java:163)
    at org.kohsuke.groovy.sandbox.impl.Checker.checkedCall(Checker.java:165)
    at com.cloudbees.groovy.cps.sandbox.SandboxInvoker.methodCall(SandboxInvoker.java:17)
    at WorkflowScript.parseParams(WorkflowScript:303)
    at WorkflowScript.run(WorkflowScript:68)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.delegateAndExecute(ModelInterpreter.groovy:137)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.executeSingleStage(ModelInterpreter.groovy:661)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.catchRequiredContextForNode(ModelInterpreter.groovy:395)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.catchRequiredContextForNode(ModelInterpreter.groovy:393)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.executeSingleStage(ModelInterpreter.groovy:660)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:288)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.toolsBlock(ModelInterpreter.groovy:544)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.toolsBlock(ModelInterpreter.groovy:543)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:276)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.withEnvBlock(ModelInterpreter.groovy:443)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.withEnvBlock(ModelInterpreter.groovy:442)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:275)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.withCredentialsBlock(ModelInterpreter.groovy:481)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.withCredentialsBlock(ModelInterpreter.groovy:480)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:274)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.inDeclarativeAgent(ModelInterpreter.groovy:586)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.inDeclarativeAgent(ModelInterpreter.groovy:585)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:272)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.stageInput(ModelInterpreter.groovy:356)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.stageInput(ModelInterpreter.groovy:355)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:261)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.inWrappers(ModelInterpreter.groovy:613)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.inWrappers(ModelInterpreter.groovy:612)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:259)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.withEnvBlock(ModelInterpreter.groovy:443)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.withEnvBlock(ModelInterpreter.groovy:442)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:254)
    at ___cps.transform___(Native Method)
    at com.cloudbees.groovy.cps.impl.ContinuationGroup.methodCall(ContinuationGroup.java:86)
    at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.dispatchOrArg(FunctionCallBlock.java:113)
    at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.fixArg(FunctionCallBlock.java:83)
    at sun.reflect.GeneratedMethodAccessor129.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.cloudbees.groovy.cps.impl.ContinuationPtr$ContinuationImpl.receive(ContinuationPtr.java:72)
    at com.cloudbees.groovy.cps.impl.ConstantBlock.eval(ConstantBlock.java:21)
    at com.cloudbees.groovy.cps.Next.step(Next.java:83)
    at com.cloudbees.groovy.cps.Continuable$1.call(Continuable.java:174)
    at com.cloudbees.groovy.cps.Continuable$1.call(Continuable.java:163)
    at org.codehaus.groovy.runtime.GroovyCategorySupport$ThreadCategoryInfo.use(GroovyCategorySupport.java:129)
    at org.codehaus.groovy.runtime.GroovyCategorySupport.use(GroovyCategorySupport.java:268)
    at com.cloudbees.groovy.cps.Continuable.run0(Continuable.java:163)
    at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.access$001(SandboxContinuable.java:18)
    at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.run0(SandboxContinuable.java:51)
    at org.jenkinsci.plugins.workflow.cps.CpsThread.runNextChunk(CpsThread.java:185)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:400)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$400(CpsThreadGroup.java:96)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:312)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:276)
    at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:67)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:131)
    at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
    at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:59)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)
Finished: FAILURE
原因：

tokenize(arg)传递的参数 arg == null
解决：

判断arg == null 时，为其赋默认值，或不能调用tokenize。