Posted on 2007-10-02
Medium Priority
Last Modified: 2010-04-01
Hi Experts,

I have this method(generic-like) that saves entries from strusts action form and analyze for some purpose. However, I am having this error and I am checking null case in my code. any idea?


public void saveEntries(ActionForm aForm, boolean fromValBtn) {
        PropertyDescriptor pd[] = PropertyUtils.getPropertyDescriptors(aForm);
for(int i=0; i<pd.length; i++){
            Method reader = PropertyUtils.getReadMethod(pd[i]);

            if(reader != null && (reader.toString().length() > 0) ){
                Object obj = reader.invoke(aForm,new Object[] {});

getter from the form

public String getFmriId() {
        fmriId = functmriseq.getFunctmriseqId().toString();
        return fmriId;

      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
      at java.lang.reflect.Method.invoke(Method.java:585)
      at org.kki.dcn.struts.utils.DcnDispatchUtilAction.saveEntries(DcnDispatchUtilAction.java:155)

Caused by: java.lang.NullPointerException
      at org.kki.dcn.hibernate.mriSeq.Seqpar.getAmriId(Seqpar.java:538)
Question by:dkim18
  • 2
LVL 92

Accepted Solution

objects earned 2000 total points
ID: 20002852
the NPE is happening in getAmriId at line 538
check that line for any references to vars that could be null, and add null checks there as required

Author Comment

ID: 20002870
yeah..i can see that. since that saveEntries method handles many forms, is there any way that I can handle such a case from that method?
LVL 92

Expert Comment

ID: 20003033
not from saveEntries(), you can't know what each method does internally.
LVL 86

Expert Comment

ID: 20004379
Isn't it all your own code? If so, why not ensure that the save is not invoked without non-null parameters?

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