配置的checkstyle xml是使用的sun_checks.xml，是通过git来获取，

 
Parsing of file '/root/.jenkins/workspace/eureka-server/eureka-server/sun_checks.xml' failed due to an exception:
java.lang.NullPointerException
[wrapped] java.net.MalformedURLException
at java.net.URL.<init>(URL.java:627)
at java.net.URL.<init>(URL.java:490)
at java.net.URL.<init>(URL.java:439)
at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.setupCurrentEntity(XMLEntityManager.java:620)
at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startEntity(XMLEntityManager.java:1304)
at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startDTDEntity(XMLEntityManager.java:1270)
at com.sun.org.apache.xerces.internal.impl.XMLDTDScannerImpl.setInputSource(XMLDTDScannerImpl.java:264)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.dispatch(XMLDocumentScannerImpl.java:1161)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.next(XMLDocumentScannerImpl.java:1045)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:959)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:602)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:505)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:842)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:771)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1213)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:643)
at org.apache.commons.digester3.Digester.parse(Digester.java:1642)
at org.apache.commons.digester3.Digester.parse(Digester.java:1745)
at edu.hm.hafner.analysis.parser.checkstyle.CheckStyleParser.parse(CheckStyleParser.java:47)
[wrapped] edu.hm.hafner.analysis.ParsingException: Exception occurred during parsing: null
at edu.hm.hafner.analysis.parser.checkstyle.CheckStyleParser.parse(CheckStyleParser.java:55)
at io.jenkins.plugins.analysis.core.model.FilesScanner.aggregateIssuesOfFile(FilesScanner.java:105)
at io.jenkins.plugins.analysis.core.model.FilesScanner.scanFiles(FilesScanner.java:89)
at io.jenkins.plugins.analysis.core.model.FilesScanner.invoke(FilesScanner.java:72)
at io.jenkins.plugins.analysis.core.model.FilesScanner.invoke(FilesScanner.java:30)
at hudson.FilePath.act(FilePath.java:1074)
at hudson.FilePath.act(FilePath.java:1057)
at io.jenkins.plugins.analysis.core.model.ReportScanningTool.scanInWorkspace(ReportScanningTool.java:147)
at io.jenkins.plugins.analysis.core.model.ReportScanningTool.scan(ReportScanningTool.java:129)
at io.jenkins.plugins.analysis.core.steps.IssuesScanner.scan(IssuesScanner.java:67)
at io.jenkins.plugins.analysis.core.steps.IssuesRecorder.scanWithTool(IssuesRecorder.java:578)
at io.jenkins.plugins.analysis.core.steps.IssuesRecorder.record(IssuesRecorder.java:546)
at io.jenkins.plugins.analysis.core.steps.IssuesRecorder.perform(IssuesRecorder.java:514)
at hudson.tasks.BuildStepCompatibilityLayer.perform(BuildStepCompatibilityLayer.java:79)
at hudson.tasks.BuildStepMonitor$3.perform(BuildStepMonitor.java:45)
at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:741)
at hudson.model.AbstractBuild$AbstractBuildExecution.performAllBuildSteps(AbstractBuild.java:690)
at hudson.model.Build$BuildExecution.post2(Build.java:186)
at hudson.model.AbstractBuild$AbstractBuildExecution.post(AbstractBuild.java:635)
at hudson.model.Run.execute(Run.java:1843)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
at hudson.model.ResourceController.execute(ResourceController.java:97)
at hudson.model.Executor.run(Executor.java:429)