db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Daniel John Debrunner <...@debrunners.com>
Subject Re: VOTE: Approach for sharing code
Date Tue, 13 Sep 2005 22:32:03 GMT
Francois Orsini wrote:

> Copying common classes to specific (tier) packages does sound good -
> However, it is true that there could be confusion during development and
> debugging if the engine and client common classes are not up to date
> (did not get re-generated) and if some developers do not necessarily
> understand how the 'common' package is managed in the codeline.

Sun seems to be thinking about this approach for J2SE, namely changing
the package names of the Apache parser into the com.sun domain to avoid
version confusion. :-)

Here's an FAQ from
http://java.sun.com/xml/jaxp/faq.html

<quote>

Q. Why are there Apache classes in the J2SE 1.4 RI?

The J2SE 1.4 RI is the first version of the JDK that bundles in an
implementation of JAXP 1.1. This allows developers to write applications
without having to provide a parser and XSLT processor with their
application. However, in some cases, it may create additional problems.

The Sun J2SE 1.4 RI uses Apache software for its implemenation of JAXP
1.1 with package names unchanged from Apache software distributions.
This can cause problems, for example, if your application wants to use a
newer version of Apache software. Under the Java 2 class loader
delegation model, the java launcher's ClassLoader will load the bundled
version of a class before any other version. Thus, if you place a newer
version of xalan.jar on your CLASSPATH, then that version will be
ignored since the runtime will use the older bundled version instead. As
a workaround, see the question on overriding the implementation in J2SE
SDK 1.4.

The future plan is to rename the org.apache.** packages to be something
like com.sun.org.apache.** to fix this problem. In addition, other
package-dependent parts of the software may also need to be modified.
However, because of lack of resources, this may not be done until after
J2SE SDK 1.4.1.

</quote>

Dan.


Mime
View raw message