getting NPE exception on rendering of page

Question

I'm getting web flow exception while rendering of the below view state. Its working fine if i directly open this view state but when i come from different flow it throws webflow exception.

I also observed that If i don't perform any action on screen and continuously open my screen for a long time, than it also throws the same exception.

My Flow file:

<view-state id="eftBatchRejection">
    <on-entry>          
        <set name="conversationScope.currentState" value="'eftBatchRejection'" />
        <set name="conversationScope.errorState" value="'eftBatchRejection'" />
        <set name="flowScope.flowValidator" value="'true'" />
        <!-- Set HELP link -->
        <evaluate expression="utilities.handleHelpUrl(conversationScope.currentState)" result="flowScope.helpURL" />            
        <evaluate expression="paymentEntryBean.setEFTRejectionBatchLayer()" />

Exception:

Attempting to handle [org.springframework.webflow.execution.ActionExecutionException: Exception thrown executing [AnnotatedAction@15aad3e targetAction = [EvaluateAction@13e5dec expression = paymentEntryBean.setEFTRejectionBatchLayer(), resultExpression = [null]], attributes = map[[empty]]] in state 'eftBatchRejection' of flow 'billing/paymentEntry' -- action execution attributes were 'map[[empty]]'] with root cause [java.lang.NullPointerException]  
2013-09-13 16:48:08 ERROR WebflowExceptionHandlerBean:90 - HANDLING FLOW EXECUTION EXCEPTION: org.springframework.webflow.execution.ActionExecutionException: Exception thrown executing [AnnotatedAction@15aad3e targetAction = [EvaluateAction@13e5dec expression = paymentEntryBean.setEFTRejectionBatchLayer(), resultExpression = [null]], attributes = map[[empty]]] in state 'eftBatchRejection' of flow 'billing/paymentEntry' -- action execution attributes were 'map[[empty]]'
org.springframework.webflow.execution.ActionExecutionException: Exception thrown executing [AnnotatedAction@15aad3e targetAction = [EvaluateAction@13e5dec expression = paymentEntryBean.setEFTRejectionBatchLayer(), resultExpression = [null]], attributes = map[[empty]]] in state 'eftBatchRejection' of flow 'billing/paymentEntry' -- action execution attributes were 'map[[empty]]'
    at org.springframework.webflow.execution.ActionExecutor.execute(ActionExecutor.java:60)
    at org.springframework.webflow.engine.ActionList.execute(ActionList.java:155)

Java Method:

public void setEFTRejectionBatchLayer() {

        if (initializeObjects == null || !(initializeObjects.equalsIgnoreCase(Constants.NO_IND))) {
            EftRejectionBatchDTO eftRejectionBatchDTO = (EftRejectionBatchDTO) UXTools.getBean(EFT_REJECTION_BATCH_DTO);

            BatchPayment batchPayment = new BatchPayment();

            MiscParty miscParty = new MiscParty();
}

Please advise me on this.Thanks in Advance!

Vikas Soni

show us the java code of `paymentEntryBean.setEFTRejectionBatchLayer()`. there occures a `NullPointerException` — Philipp Sander, Sep 13 '13 at 16:07
Bean Class:@Component @Scope("flow") public class PaymentEntryBean implements Serializable {.......} The scope is "flow". — Vikas, Sep 17 '13 at 11:24

score 1 · Answer 1 · answered Sep 18 '13 at 21:12

was just looking into webflow problems,and even if it is not your main concern, i may have found a partial explanation for the when your bug occurs and when not.

The "on-entry" expression code is only executed when this view-state is accessed from the webflow logic, and is not if you access this flow state from a refresh or direct access to a previously rendered view (by typing directly in url .... = e1s5 for e.g.)

It does not solve your problem but i think it could explain the conditions of its reproduction.

Your actions are always leading to an unhandled error (to investigate in your java code), but your actions are not always executed.

You could check on that by moving your actions to an "on-render" section instead, and then your error should show up every time you acces this view, in any fashion.

Either way i think it's a tip of interest.

Goog luck!

score 0 · Answer 2 · answered Apr 06 '16 at 19:47

late response but anyway...

this may not answer this question but I thought it might help others...

when we get errors like Attempting to handle [org.springframework.....action execution attributes were 'map[[empty]]'] with root cause , it means that the form data from jsp is not being transferred.

try replacing the line

<view-state id="eftBatchRejection">

with

<view-state id="eftBatchRejection" model="beanName">

getting NPE exception on rendering of page

2 Answers2