BeanWrapperFieldSetMapper - Is this a JIRA issue?

[vbforums]

Hi,

I am using the BeanWrapperFieldSetMapper, to convert the file content to Object. If I have the below class structure

public class A{
   int attrA1;
   int attrA2;
}

public class B{
    A classAinst;
}

When feeding the file for Object B using BeanWrapperFieldSetMapper below line of code

	public Object mapLine(FieldSet fs) {
		Object copy = getBean();

creates only object B with null instance of A. This throws an NullPointerException.

Question: Is this an bug in the code or there is a way to handle it. Instantiating the classAinst in the constructor B is not an option as Class B is also used by UI/core business classes.

Your answer to this question is much appreciated. Thanks in advance for your help.

Thanks,
vbforums

[Dave Syer]

BeanWrapperFieldSetMapper has a prototypeBeanName property which you need to use if there are complex configuration or instantiation requirements (i.e. as in your case where the default constructor doesn't provide a fully formed prototype).

[vbforums]

Agreed, this resolves the issue of NULL child object.

Another problem that I see is, lets say class A mapped to tableA and class B mapped to tableB, if all the parameters of class B is null in the file(for some rows) this creates a dummy row in tableB.

Is there is a way to avoid this?

[Dave Syer]

Insert a validation check or ItemProcessor (2.0) / ItemTransformer (1.x) that removes empty elements?

[vbforums]

Thanks for your response and guidance Dave. I will go this route.

If this checking is in-built in the batch framework its a nice to have else we have to build a class for each of our batch operations to perform.

Also, can you please respond to my other thread, I am eagerly waiting for some one to reply. Topic "Retrieving Error message, skipped record, line number "

http://forum.springframework.org/showthread.php?t=62970

[Dave Syer]

If this checking is in-built in the batch framework its a nice to have else we have to build a class for each of our batch operations to perform.

If you open an issue in JIRA you'll give people a chance to comment and vote. You'll need to be a bit more precise about the new feature though.

[vbforums]

Yep, I have created the below JIRA issue for this

http://jira.springframework.org/browse/BATCH-924