Re: different try-finally approach

From:
Daniel Pitts <newsgroup.spamfilter@virtualinfinity.net>
Newsgroups:
comp.lang.java.programmer
Date:
Tue, 04 Aug 2009 20:12:57 -0700
Message-ID:
<5N6em.110851$vp.62147@newsfe12.iad>
Pitch wrote:

In java it is common to check if the resource is null in finally
statement, before closing it:

public void doSomething() throws MyResourceException
{
  MyResource res = null;
  try
  {
    res = new MyResource();
    // do something
  }
  finally
  {
    if (res != null) res.close()
  }
}

But in some other languages this is the preferred way:

public void doSomething() throws MyResourceException
{
  MyResource res = new MyResource();
  try
  {
    // do something
  }
  finally
  {
    res.close()
  }
}

The first example ensures nothing more than the second one, right? If
the constructor throws an exception the "res" is null, so it can't be
closed anyways.

So, my question is - why the extra coding in java? Am I missing
something?


MyResource res1 = new MyResource("a");
MyResource res2 = new MyResource("b"); // throws exception
oops, res2 is null, but res1 is not.

This is why I miss RAII from C++.

--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/>

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