Issue with generating excel sheets in a web application - java

While working in a web application I have some issues with generating the excel sheet based on the result. This excel sheet data should be independent for each request. As of now I have implemented in the following way:
Created a xml file for excel configuration
spring-excel-views.xml
<bean id="excelView" class="com.test.service.excelService"
I have configure this xml in the servlet configuration file
<bean class="xmlReolver> //Mentioned clearly in the code but not here
<property name="location>
<value>bin/spring-excel-views.xml</value>
</property>
</bean>
Now I have controller class as well as an Utility class
UtiilityClass: computes the results and send back to the Controller
Controller: model.addAttribute("result", result); //Assuming result is coming for Utility class
Now in excelService.java coded as follows:
class ExcelService implements AbstractExcelView{
#overridden
protected void buildExcelDocument(Map model,HttpServletRequest req, HTTPServletResponse res){
Map m = model.getResults("results"); // Picking this from Controller
for(Map.Entry<Integer,String> entry: m.entrySet()){ -->Exception is throwing
//excel sheet logiic
}
//iteration logic ----> Exception thrown here
}
}
Here sometimes excel sheet is generating successfully and sometimes it is throwing Nullpointerexception before starting the iteration. Also this excel data is overriding with some other requests data. Displayed result is good but I'm having the problem with the excel sheet data.
Help me out to resolve this issue.
Exception Stack trace
Exception Report:
type Exception report
message Request processing failed; nested exception is java.lang.NullPointerException
description: The server encountered an internal error that prevented it from fulfilling this request.
exception:
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.
org. springframework. web. servlet. FrameworkServlet . processRequest (FrarneworkServlet. java: 932)
org.springframework.web.servlet.FrameworkServlet.doGet(Frameworkservlet.java:816)
javax.servlet.http.HttpServlet.service (HttpServlet.java: 620)
org.springframework.web.servlet.FrameworkServlet.service (FrameworkServlet.java:801)
javax.servlet.http.Httpservlet.service(Httpservlet.java:727)
root cause
java.lang.NullPointerException
com. hello. services.ExcelService.buildExcelDocument (Excelservice.java:34)
org. springframework.web.servlet.view.document.AbstractExcelView.renderMergedoutputModel (AbstractE
org.springfranework.web.servlet.view.AbstractView.render (AbstractView.java:264)
org.springframework.web.servlet.DispatcherServlet.render (Dispatcherservlet.java: 1208)
org. springframework . web . serviet . DispatcherServlet . processDispatchResult (DispatcherServlet . java: 1208
org. springframework. web. servlet . DispatcherServlet . doDispatch (DispatcherServlet . java: 939)
org. springframework.web.servlet.DispatcherServlet.doService (DispatcherServlet.java:856)
org. springframework.web.servlet.FrameworkServlet.processRequest (FrameworkServlet.java: 920)
org. springframework.web.servlet.FrameworkServlet.doGet (FrameeworkServlet.java:816)
javax.servlet.http.Httpservlet.service(Httpservlet.java: 620)
org.springframework.web.servlet.FrameworkServlet.service (FraneworkServlet.java:801)
javax.servlet.http.HttpServlet.service(Httpservlet.java:727)

As you pointed out that exception is throwing in the below line
for(Map.Entry entry: m.entrySet()){ -->Exception is throwing
You are getting this exception because model.getResults("results") is returning null.Thus your m is assigned null and doing m.entrySet() this on null reference is throwing null pointer exception.
So you'll have to figure out why model.getResults("results") is returning null and fix it. If there can occur situation where there will be no excel sheet generated and model.getResults("results") will return nulll. Then you'll have to provide appropriate checking in your code.Below is a checking but it may not be sufficient as you may to handle some more stuffs.
if(m!=null){
for(Map.Entry<Integer,String> entry: m.entrySet()){ -->Exception is throwing
//excel sheet logiic
}
//iteration logic ----> Exception thrown here
}
Regarding you question about Thread safe it completely depends how you have designed your class and using it which is very difficult to answer just by looking at the few lines. However this may not be an issue of Thread safe.

Related

FusionAuth incomplete reindex with AWS Elasticsearch

I am migrating from a self-hosted Elasticsearch FusionAuth search to an AWS Elasticsearch Service solution.
I have a new FusionAuth app EC2 instance reading from the in-use database that is configured to use the new Elasticsearch service.
On triggering a reindex from the new app instance I see that only around 60k or 62.5k documents are being written to the new index when I am expecting roughly 6mil.
I see no errors from AWS's Elasticsearch Service and in the app's logs I can see: (endpoint intentionally omitted)
Feb 13, 2020 10:18:46.116 AM INFO io.fusionauth.api.service.search.ElasticSearchClientProvider - Connecting to FusionAuth Search Engine at [https://vpc-<<omitted>>.eu-west-1.es.amazonaws.com]
13-Feb-2020 11:19:55.176 INFO [http-nio-9011-exec-3] org.apache.coyote.http11.Http11Processor.service Error parsing HTTP request header
Note: further occurrences of HTTP header parsing errors will be logged at DEBUG level.
java.lang.IllegalArgumentException: Invalid character found in method name. HTTP method names must be tokens
at org.apache.coyote.http11.Http11InputBuffer.parseRequestLine(Http11InputBuffer.java:430)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:684)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:808)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1498)
"/usr/local/fusionauth/logs/fusionauth-app.log" [readonly] 43708L, 4308629C 42183,1 96%
at io.fusionauth.api.service.search.client.domain.documents.IndexUser.<init>(IndexUser.java:79)
at io.fusionauth.api.service.search.ElasticsearchSearchEngine.lambda$index$1(ElasticsearchSearchEngine.java:140)
at java.util.ArrayList.forEach(ArrayList.java:1257)
at io.fusionauth.api.service.search.ElasticsearchSearchEngine.index(ElasticsearchSearchEngine.java:140)
at io.fusionauth.api.service.user.ReindexRunner$ReindexWorker.run(ReindexRunner.java:101)
at java.lang.Thread.run(Thread.java:748)
Exception in thread "Thread-14" java.lang.NullPointerException
at io.fusionauth.api.service.search.client.domain.documents.IndexUser.<init>(IndexUser.java:79)
at io.fusionauth.api.service.search.ElasticsearchSearchEngine.lambda$index$1(ElasticsearchSearchEngine.java:140)
at java.util.ArrayList.forEach(ArrayList.java:1257)
at io.fusionauth.api.service.search.ElasticsearchSearchEngine.index(ElasticsearchSearchEngine.java:140)
at io.fusionauth.api.service.user.ReindexRunner$ReindexWorker.run(ReindexRunner.java:101)
at java.lang.Thread.run(Thread.java:748)
Exception in thread "Thread-13" java.lang.NullPointerException
Exception in thread "Thread-11" java.lang.NullPointerException
Exception in thread "Thread-12" java.lang.NullPointerException
Feb 18, 2020 10:23:29.064 AM INFO io.fusionauth.api.service.user.ReindexRunner - Reindex completed in [86797] ms or [86] seconds.
Although there are some exceptions there is also an "Reindex completed" INFO log at the end.
Not knowing the ins-and-outs of Elasticsearch I'm also not sure where to start in investigating a NullPointerException.
It looks like the re-index operation is taking an exception which is likely the cause of the truncated index.
Exception in thread "Thread-14" java.lang.NullPointerException
at io.fusionauth.api.service.search.client.domain.documents.IndexUser.<init>(IndexUser.java:79)
This code makes an assumption that you have a username or email address. This should be enforced by the FusionAuth APIs. But in this case, for this exception to occur the email and username are both NULL.
How did you get users into the db, using the Import API, User API, or something else?
In theory you should find at least one user with a NULL value for the email and username.
This query - or similar - should find the offending user, then we need to identify how this user was added to FusionAuth.
SELECT email, username from identities WHERE email IS NULL OR username IS NULL

Servlet doGet() returns HTTP Status 500

while i was learning servlet i used the method doGet() and i was using Get request method ,the HTTP Status 500 error showed up ,but while using doPost() and post request was working perfectly fine.why am i not able to work with the doGet().
HTTP Status 500 – Internal Server Error
Type Exception Report
Message null
Description The server encountered an unexpected condition that prevented it from fulfilling the request.
Exception
java.lang.NumberFormatException: null
java.lang.Integer.parseInt(Unknown Source)
java.lang.Integer.parseInt(Unknown Source)
com.kiran.AddServlet.doGet(AddServlet.java:12)
javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Note The full stack trace of the root cause is available in the server logs.
Apache Tomcat/9.0.27
It seems like i was trying to parse a number that is null.
From your snippet stack trace it looks like you’re trying to parse a null number.

How to diagnose "org.restlet.data.Parameter cannot be cast to org.restlet.data.Header" error in Restlet 2.3.5?

I'm using Restlet 2.3.5 in my application. When the GET request handler of a certain server resource is invoked, I get the following error:
[10:26:04] [Restlet-860541310/WARN]: Nov 29, 2015 10:26:04 AM org.restlet.engine.adapter.ServerAdapter addResponseHeaders
WARNING: Exception intercepted while adding the response headers
java.lang.ClassCastException: org.restlet.data.Parameter cannot be cast to org.restlet.data.Header
at org.restlet.engine.header.HeaderUtils.addExtensionHeaders(HeaderUtils.java:226)
at org.restlet.engine.header.HeaderUtils.addResponseHeaders(HeaderUtils.java:653)
at org.restlet.engine.adapter.ServerAdapter.addResponseHeaders(ServerAdapter.java:83)
at org.restlet.engine.adapter.ServerAdapter.commit(ServerAdapter.java:184)
at org.restlet.engine.adapter.HttpServerHelper.handle(HttpServerHelper.java:144)
at org.restlet.engine.connector.HttpServerHelper$1.handle(HttpServerHelper.java:64)
at com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:77)
at sun.net.httpserver.AuthFilter.doFilter(AuthFilter.java:83)
at com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:80)
at sun.net.httpserver.ServerImpl$Exchange$LinkHandler.handle(ServerImpl.java:677)
at com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:77)
at sun.net.httpserver.ServerImpl$Exchange.run(ServerImpl.java:649)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
The problem is that this exception is thrown outside of the code that I wrote (I added logging statements in my server resource and according to them, the exception is thrown somewhere else).
As a result, I get 500 response (internal server error), even though my server resource sends correct data back to the client.
How can I find out, what exactly is causing this error?
This could be caused when trying to add custom headers in Restlet. When initializing the corresponding map, you would use a map (Series in Restlet) of Parameter instead of Header...
You can use something like that:
Series<Header> responseHeaders = (Series<Header>)
response.getAttributes().get(HeaderConstants.ATTRIBUTE_HEADERS);
if (responseHeaders == null) {
responseHeaders = new Series(Header.class);
response.getAttributes().put(
HeaderConstants.ATTRIBUTE_HEADERS, responseHeaders);
}
responseHeaders.add(new Header("X-MyHeader", "value"));
Hope it helps you,
Thierry

Web-service client on Websphere throws NullPointer on method calling

We've been using
jaxws-spring
WebSphere 8.5.5.2
for our web-services interactions, and now we get stuck with such "cause" when we call any web-method on the client-side -
ServletWrappe E com.ibm.ws.webcontainer.servlet.ServletWrapper service SRVE0014E: Uncaught service() exception root cause appServlet:
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is javax.xml.ws.soap.SOAPFaultException: java.lang.NullPointerException
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:948)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:827)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:575)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812)
.....
Caused by: javax.xml.ws.soap.SOAPFaultException: java.lang.NullPointerException
at org.apache.axis2.jaxws.marshaller.impl.alt.MethodMarshallerUtils.createSystemException(MethodMarshallerUtils.java:1363)
at org.apache.axis2.jaxws.marshaller.impl.alt.MethodMarshallerUtils.demarshalFaultResponse(MethodMarshallerUtils.java:1089)
at org.apache.axis2.jaxws.marshaller.impl.alt.DocLitWrappedMethodMarshaller.demarshalFaultResponse(DocLitWrappedMethodMarshaller.java:680)
at org.apache.axis2.jaxws.client.proxy.JAXWSProxyHandler.getFaultResponse(JAXWSProxyHandler.java:626)
....
Caused by: java.lang.NullPointerException
at java.util.concurrent.ConcurrentHashMap.put(ConcurrentHashMap.java:946)
at org.apache.axis2.jaxws.message.databinding.JAXBUtils.getJAXBContext(JAXBUtils.java:445)
at org.apache.axis2.datasource.jaxb.JAXBDSContext.getJAXBContext(JAXBDSContext.java:228)
at org.apache.axis2.datasource.jaxb.JAXBDSContext.getJAXBContext(JAXBDSContext.java:161)
at org.apache.axis2.datasource.jaxb.JAXBDSContext.marshal(JAXBDSContext.java:396)
at org.apache.axis2.jaxws.message.databinding.impl.JAXBBlockImpl._outputFromBO(JAXBBlockImpl.java:189)
at org.apache.axis2.jaxws.message.impl.BlockImpl.outputTo(BlockImpl.java:371)
at org.apache.axis2.jaxws.message.impl.BlockImpl.serialize(BlockImpl.java:295)
at org.apache.axiom.om.impl.llom.OMSourcedElementImpl.internalSerialize(OMSourcedElementImpl.java:781)
at org.apache.axiom.om.impl.llom.OMElementImpl.internalSerialize(OMElementImpl.java:967)
at org.apache.axiom.soap.impl.llom.SOAPEnvelopeImpl.serializeInternally(SOAPEnvelopeImpl.java:283)
at org.apache.axiom.soap.impl.llom.SOAPEnvelopeImpl.internalSerialize(SOAPEnvelopeImpl.java:245)
at org.apache.axiom.om.impl.llom.OMSerializableImpl.serializeAndConsume(OMSerializableImpl.java:207)
at org.apache.axis2.transport.http.SOAPMessageFormatter.writeTo(SOAPMessageFormatter.java:74)
Web-service client initialisation comes out with no any errors -
URL service_endpoint;
service_endpoint = new URL(endpoint);
service = new UDHandlersServiceImpl(service_endpoint, SERVICE_QNAME).getUDHandlersServiceImplPort();
NullPointerException occurs after calling any method of "service". And it doesn't even reach server side - because it doesn't have any logs there. Furthermore - such situation occurs only on the WebSphere - we deployed our client application on the Tomcat (server remained on websphere) and it worked fine. One more thing - SoapUI does not have any problems interacting with server side too.
We tried to switch classLoadings to parentLast for client application - with no success.
Also I can't even find sources for "org.apache.axis2.jaxws.message.databinding.JAXBUtils.getJAXBContext(JAXBUtils.java:445)". I googled it and didn't find this version of JAXBUtils. But even if i did, i think, it wouldnt be useful...
I hope someone can help us with that unobvious problem.
Thanks beforehand.
===== updated======
When we remove jaxb libraries from endorsed dir (or appServer/classes) problem seems to disappear but in case of arising webExceptions(faults) server throws
Caused by: java.lang.ClassCastException: com.ibm.xml.xlxp2.jaxb.JAXBContextImpl incompatible with com.sun.xml.bind.api.JAXBRIContext
at com.sun.xml.ws.fault.SOAPFaultBuilder.<clinit>(SOAPFaultBuilder.java:565)
at java.lang.J9VMInternals.initializeImpl(Native Method)
at java.lang.J9VMInternals.initialize(J9VMInternals.java:237)
and returns no answer to the client.
We've realized that our exceptions didn't contain 3 required methods -
//============required==================
public DocumentValidationException(String message, ErrorsBean errorsBean, Throwable cause) {
super(message, cause);
this.errorsBean = errorsBean;
}
public ErrorsBean getFaultInfo() {
return errorsBean;
}
public DocumentValidationException(String message, ErrorsBean errorsBean) {
super(message);
this.errorsBean = errorsBean;
}
//======================================
so, now it does.
And also we had some wrong target namespaces in it at the #WebFault annotations.
Here is the link with similar problem - https://www.ibm.com/developerworks/community/forums/html/topic?id=77777777-0000-0000-0000-000014076927#77777777-0000-0000-0000-000014083314

MongoDB API for Java : MongoInternalException on accessing a DBCursor

After successfully connecting to the MongoDB database, I'm receiving this exception when trying to go through a DBCursor :
Exception in thread "main" com.mongodb.MongoInternalException: couldn't get next element
at com.mongodb.DBCursor.hasNext(DBCursor.java:448)
Here is the code, the line with the while condition is the one raising the exception :
DBCollection upages = db.getCollection("upages");
DBCursor pageviewedbyuser = upages.find();
while (pageviewedbyuser.hasNext()) {
etc etc
}
When accessing the upages collection from the Mongo shell, it seems clear that it's not empty. The DBCursor seems to be successfully loaded because there is this line in the error log :
SEVERE: MyPort.error called
java.io.IOException: finished reading objects but still have: 19553 bytes to read!'
Has anybody run into this error before? Any idea?

Categories