Tuesday, December 29, 2009

Re: [Java] Guidance on Struts 1.3

 

Hello Mayank,

That just did the trick! Thanks a lot for your response.

Thank you!!!
TS

2009/12/24 Mayank Singh <want2meetmayank@yahoo.co.in>

>
>
> In your page.jsp
>
> you have written
>
> *"<html:text property="onlyChild.name"/>"*
>
> *now you are trying to access "name" field within "onlyChild" object, which
> is null or not initialized.*
>
> To get rid of this problem, you can modify your getter method of
> "onlyChild"
> field in Father class from
>
> public Child getOnlyChild() {
> return this.onlyChild
> }
>
> to
>
> public Child getOnlyChild() {
> if(this.onlyChild == null)
> this.onlyChild = new Child(); //Initialize the object
> return this.onlyChild
> }
>
> From next time, make sure that whenever you have to access any property of
> an object within JSP, the parent object is initialized. Struts tag library
> can only take of uninitialized property if they are of primitive data type
> or wrapper classed. For eg. String, Integer, Float, Double etc...
>
> I hope this helps.
>
> Thanks.
>
> On Tue, Dec 22, 2009 at 11:22 PM, Thiago Santana <thiagoecatia@gmail.com<thiagoecatia%40gmail.com>
> >wrote:
>
>
> >
> >
> > Hello,
> >
> > My previous use of Struts was on a very very simple application and I was
> > able to do well with it. But now I am have a more complex model which I
> am
> > not being able to get around with as I have to build a html form whose
> > property maps to the attribute of an attribute of the ActionForm. My
> doubt
> > relies on how to access this "sub-attribute" on teh html form?
> >
> > In case this is not to clear, I have the following, very unreal scenario:
> >
> > package sample;
> >
> > import java.util.*;
> > import org.apache.actions.*;
> >
> > public class Father extends ActionForm{
> >
> > private String name;
> > private Child onlyChild;
> >
> > //....Getters and setters....//
> > }
> >
> > ---------------------------------------------------------
> >
> > package sample;
> >
> > import java.util.*;
> > import org.apache.actions.*;
> >
> > public class Child extends ActionForm{
> >
> > private String name;
> > private int age;
> >
> > //...Getters and setters...//
> > }
> >
> > ----------------------------------------------------------
> >
> > page.jsp
> >
> > (...)
> >
> > <html:form action="fatherAction">
> > Name: <html:text property="name"/><br/>
> > <b>Child details</b><br/>
> > Only child name: <html:text
> > property="onlyChild.name"/><!--????????--><br/>
> > Only child age: <html:text
> > property="onlyChild.age"/><!----????????????--->
> > </html:form>
> >
> > (...)
> >
> > ----------------------------------------------------------
> >
> > When I try it like the example above I get error as it the
> > onlyChild.whatever does not exist, does no map to a known attribute it is
> > null.... Please let me know how to achieve that... Your help is much
> > appreciated...
> >
> > Merry Xmas in advance!!!
> >
> > --
> > Thank you,
> > TS
> > +55 21 7524-9415
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
>
> --
> Mayank
>
> [Non-text portions of this message have been removed]
>
>
>

--
Thank you,
TS
+55 21 7524-9415

[Non-text portions of this message have been removed]

__._,_.___
Visit http://aiaiai.com or http://jgame.org for more groups to join.
Java Official Group is created for the following topics: Java 2 Enterprise Edition - J2EE, Java 2 Standard Edition - J2SE, Java 2 Micro Edition - J2ME, XML, XSL, XSD, XPATH, Web Services, Jini, JXTA for all type of Java Geeks.
Whoever posts spam / ads / job related message will be BANNED IMMEDIATELY
.

__,_._,___

No comments:

Post a Comment