Re: Think I'm stuck with using Session scope for this..unless a better idea?

[Rick Reumann]

Thanks for the detailed info Niall. I might try something like this.
Niall Pemberton wrote the following on 9/16/2004 3:15 AM:
Sorry, should have read the whole thread - I missed the fact you don't have
control of FooBar.
You're probably right, session scope is probably the easiest, although you
could do this by creating a FooBarWrapper using the WrapDynaBean (needs
BeanUtils 1.7.0 to use the getInstance() method).
The following class should work:
   a) create warpper for existing FooBar
            FooBarWrapper wrapper = new FooBarWrapper(fooBar);
   b) Retrieve FooBar from populated wrapper and clean up
           FooBar fooBar = (FooBar)wrapper.getInstance();:
           wrapper.clear();

import java.util.List;
import java.util.Collection;
import java.util.ArrayList;
import java.util.Iterator;
import org.apache.commons.beanutils.WrapDynaBean;
public class FooBarWrapper extends WrapDynaBean {
  private List wrapperList = new ArrayList();
  public FooBarWrapper() {
    super(new FooBar());
  }
  public FooBarWrapper(FooBar fooBar) {
    super(fooBar);
    Collection fooBars = fooBar.getFooBars();
    if (fooBars != null) {
      Iterator iterator = fooBars.iterator();
      while (iterator.hasNext()) {
        wrapperList.add(new FooBarWrapper((FooBar)iterator.next()));
      }
    }
  }
  public Object get(String name) {
    if ("fooBars".equals(name)) {
      return wrapperList;
    }
    return super.get(name);
  }
  public Object get(String name, int index) {
    if ("fooBars".equals(name)) {
      if (wrapperList.size() <= index) {
        while (wrapperList.size() <= index) {
          FooBarWrapper childWrapper = new FooBarWrapper();
          wrapperList.add(childWrapper);
          FooBar childFooBar = (FooBar)childWrapper.getInstance();
          FooBar fooBar = (FooBar)getInstance();
          if (fooBar.getFooBars() == null) {
            fooBar.setFooBars(new ArrayList());
          }
          fooBar.getFooBars().add(childFooBar);
        }
      }
      return wrapperList.get(index);
    }
    return super.get(name, index);
  }
  public void clear() {
    for (int i = 0; i < wrapperList.size(); i++) {
      FooBarWrapper wrapper = (FooBarWrapper)wrapperList.get(i);
      wrapper.clear();
    }
    instance = null;
    wrapperList.clear();
    wrapperList = null;
  }
  public String toString() {
    return getInstance().toString();
  }
}
----- Original Message ----- 
From: "Rick Reumann" <[EMAIL PROTECTED]>
To: "Struts Users Mailing List" <[EMAIL PROTECTED]>
Sent: Thursday, September 16, 2004 5:45 AM
Subject: Re: Think I'm stuck with using Session scope for this..unless a
better idea?


Niall Pemberton wrote the following on 9/16/2004 12:41 AM:

"I don't see how this is going to work though. The problem is I'm
getting
back an Object (the FooBar one) from the back end that has the nested
collections inside. This isn't a Struts object (not of type
ActionForm)."
I guess what meant was the object I'm dealing with is "handed" to me.
It's not an object that I have that much control of since it's coming
from the business layer (not coded by me) so not sure I can say "start
implmenting lazyList stuff in there.

Hadn't really been following this thread, but isn't the trick to getting
round the BeanUtils issue all in the getFooBar(index) method. I don't
use
LazyList, but if it was an array - wouldn't something like the following
work
private FooBar[] fooBars;
public FooBar getFooBar(int index) {
The problem is there are not getXXX(int index) methods in the business
objects. The initial post mentions I'm stuffing one object into my form:
class MyForm extends ActionForm {
   private FooBarValueObject fooBar;
   //get/set fooBar
}
FooBarValueObject has a few properties but the main one of interest being:
Collection fooBars;
Which end up being Collections of other FooBarValueObjects.
It's not a big deal. I'm just going to use Session scope. If performance
becomes an issue I'll work on some listner thing that Michael talked
about that cleans it up. (I've actually yet run into a case where
keepign stuff in a User's Session caused serious memory problems... then
again I'm not working on Amazon.com or anything:)

   if (fooBars == null) {
       fooBars = new FooBar[index];
   }
   if (fooBars.length <= index) {
       FooBar[] newFooBars = new FooBar[index + 1];
       System.arraycopy(foobars, 0, newFooBars, 0, fooBars.length);
       fooBars = newFooBars;
   }
   if (fooBars[index] == null) {
       fooBars[index] = new FooBar();
   }
   return fooBars[index];
}
--
Rick
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]



---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]

--
Rick
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]