nested exception is java.lang.NullPointerException] with root cause while running application on remote machine

[jamshaid120]

I've installed the application on a remote linux machine. After I run the app with gradle bootrun, it throws the below error while running the rules. It works fine when I run in the local machine.

`2020-03-16 03:27:57.282 ERROR 24422 --- [nio-8080-exec-4] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause

java.lang.NullPointerException: null
at com.NadiaRS.InferenceEngine.ruleParser.RuleSetParser.handleChild(RuleSetParser.java:347) ~[main/:na]
at com.NadiaRS.InferenceEngine.ruleParser.RuleSetScanner.scanRuleSet(RuleSetScanner.java:99) ~[main/:na]
at com.NadiaRS.controller.InferenceController.setInferenceEngine(InferenceController.java:202) ~[main/:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133) ~[spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97) ~[spring-webmvc-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) ~[spring-webmvc-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) ~[spring-webmvc-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967) ~[spring-webmvc-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901) ~[spring-webmvc-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) ~[spring-webmvc-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) ~[spring-webmvc-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:687) ~[javax.servlet-api-3.1.0.jar:3.1.0]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) ~[spring-webmvc-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) ~[javax.servlet-api-3.1.0.jar:3.1.0]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.23.jar:8.5.23]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:108) ~[spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) ~[spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) ~[spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]

`

[DeanLee77]

can you send me a rule set you used in the server? it seems that there was an issue with rules.

[jamshaid120]

I am using Testing for ALL Node Lines and features.txt from https://github.com/DeanLee77/Nadia/tree/master/bin/testingPackage/testing10.
It works fine on the localhost on my machine but when I run it on a remote machine, it causes the issue. It reads the rule correctly. I've tested printing parentText in the method
` @OverRide
public void handleParent(String parentText, int lineNumber) {

	Node data = nodeSet.getNodeMap().get(parentText);
	System.out.println("parentText "+ parentText);

`
It gives the same output on both local and remote machine

[jamshaid120]

There's a difference in the output of the above method on both local and remote machines.
Local Machine produces indexOfRuleToBeAsked : 1 after the ouput of System.out.println("parentText "+ parentText); ends but remote machine doesn't print it.

[DeanLee77]

it is .RuleSetParser.handleChild(RuleSetParser.java:347) issue in com.NadiaRS/InferenceEngine/ruleParser
it might be a reason that Node object was not created or there was no NodeSet object created. but still it does NOT make sense to me. can you put a log to print 'data' instance of Node class or NodeSet instance named nodeSet?

[jamshaid120]

datanull datanull datanull datanull datanull datanull datanull datanull datanull datanull datanull datanull datacom.NadiaRS.InferenceEngine.nodePackage.ValueConclusionLine@2d8f9195 datanull datanull datanull datanull datanull datacom.NadiaRS.InferenceEngine.nodePackage.ValueConclusionLine@46a20799 datacom.NadiaRS.InferenceEngine.nodePackage.ValueConclusionLine@5a90b0b2 datacom.NadiaRS.InferenceEngine.nodePackage.ValueConclusionLine@1ade2363 datacom.NadiaRS.InferenceEngine.nodePackage.ValueConclusionLine@135c5d6e
While printing node object from
Node data = nodeSet.getNodeMap().get(parentText);, it gives the above output

[jamshaid120]

for nodeSet object, when I run System.out.println("nodeSet ",nodeSet);
nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee nodeset com.NadiaRS.InferenceEngine.nodePackage.NodeSet@51bb83ee

[DeanLee77]

it seems that you printed Node object in a 'handleParent(String parentText, int lineNumber)'.
Can you put ' System.out.println("line number: " + lineNumber); System.out.println("data : "+data.getNodeName()); ' at line:345 in RuleSetParser class, which is inside of 'handleChild()' method?

[jamshaid120]

output.txt
Here is the output. It doesn't print line 118 to 120 which I am getting on my local machine

[DeanLee77]

hum... I have looked at the output file, and was wondering if the NADIA crushed after attempt to read line 118 of the rule file or not.
I found that it only printed upto line 117 even there is a number of lines after that, and strangely a line number of 118 should be printed if there was an issue on parsing the line but the line number was not printed.

[jamshaid120]

Yeah. Some issue occurs after 117 and it crashes. I've tested other files as well but when the last 3 or 4 lines are left, it throws the exception. On the local machine, it doesn't behave like that

[jamshaid120]

I cloned the repository to a new folder. and started it again. It is working fine this time. I don't know what was the issue behind it

[DeanLee77]

Glad to hear that it is working now. sometimes Java works funny. Anyhow, when you need help, let me know. by the way, what is the entire project about, may I ask?

[jamshaid120]

I tried running https://github.com/DeanLee77/Nadia/tree/master/bin/testingPackage/testing10 but it throws the same error. For https://github.com/DeanLee77/Nadia/blob/master/bin/testingPackage/testing2/Wedding%20Planner.txt
this test, it is working fine on the remote machine. I don't know what might be causing the issue.

[jamshaid120]

They are working on deploying a system that works like your application. I didn't ask for many details. The UI for this app is kinda difficult for a user.

[DeanLee77]

so the application in the server does NOT work for a file, https://github.com/DeanLee77/Nadia/blob/master/bin/testingPackage/testing10/Testing for ALL Node Lines and features.txt?

but works with the file, 'https://github.com/DeanLee77/Nadia/blob/master/bin/testingPackage/testing2/Wedding Planner.txt '.

Do I understand correctly?