[jdom-interest] NoSuch*Exceptions in JDOM

[Andre Van Delft]

Jason Hunter wrote:

> I'm still flexible.  But let me say, I'm not swayed by the "ivory tower"
> question of "is this exceptional or not" but rather I'm swayed by use
> cases that make one approach more appealing than the other.
> Unfortunately, selecting either approach currently involves making
> certain use cases overly complicated.  So, other things being equal, I'm
> currently supporting throwing exceptions because I just know returning
> null means there'll be a lot of damn NullPointerException errors,
> without any decent description of what went wrong.  Sirtaj Singh Kang
> made some very compelling arguments along these lines.
>
I am developing a program that transforms XML into HTML, using JDOM and ECS.
A typical code snippet is:

  String str = "";
  try {
     // DTD: jnl = jtl,sbt?,...
     str += jnl.getChild("JTL").getContent();
     org.jdom.Element sbt   = getChild(jnl, "SBT");
     if (sbt != null) str += sbt.getContent();
     ...;
  }
  catch (NoSuchElementException e)
  {
     handle (target, e);
  }

Here getChild(jnl, "SBT") is a call to my util function
that returns null instead of throwing an exception.
The null test is exactly what I want for an optional element.
The catch clause is only handling real exceptions.
Without my util function, the code would be far more
complicated:

  String str = "";
  try {
     // DTD: jnl = jtl,sbt?,...
     str += jnl.getChild("JTL").getContent();
     try {
        str += jnl.getChild("SBT").getContent();
     }
     catch (NoSuchElementException e)
     {
          // nothing to do; is OK
     }
     ...;
  }
  catch (NoSuchElementException e)
  {
     handle (target, e);
  }

IMHO: instead of everybody making his own util functions,
JDOM should provide the desired function variations.