[BNE-PM] What do you use Perl for?

[Tony Obermeit]

Derek, I appreciate your comments and questions.  Please take my comments 
as my perspective, I don't want to start a flame war....

At 02:28 PM 20/08/2002 +1000, Derek Thomson wrote:
>Tony Obermeit wrote:
>>My development is categorised in three areas, application development 
>>(web/html applications with database (sql/oracle) back ends), build 
>>scripts to support application development, ad-hoc scripts.
>
>The Perl DBI database integration is very good, indeed. And it comes with 
>a command line tool that is sometimes superior to the one shipped with the 
>product (I'm looking at you, Oracle :).

I agree that the perl dbi database integration is very good, it is one of 
the compelling reasons to choose perl over other scripting languages for 
shell scripting type of tasks.

>>Previously I used perl for all three of these areas, now I use java for 
>>application development, ant for build scripts and perl for ad-hoc scripts.
>
>Okay, my question is: what technical reason is there for using Java for 
>web applicatoins instead of Perl?

When using perl as a language for developing an application that will be 
deployed to many sites, with a variety of configurations, I found perl to 
be challenging.  Some of the issues I had were:

(1) I didn't want to ship my source code.  With java I am able to ship only 
compiled .class files.  This gives me a significantly higher level of 
confidence that a bug hasn't occurred because someone hacked the source code.

(2) When I installed my perl scripts, I had to edit each script to replace 
the path to the perl interpreter if the perl interpreter was installed in a 
different directory to mine, particularly worse when trying to keep the 
application working on unix and Windows NT/2k.  This caused me concern in 
regard to the installation of my application.

(3)  I had challenges getting dbi/dbd::oracle working in a linux 
environment, with java, jdbc just seemed to work in any environment.

(4) Ease of installation of a finished application, with perl I had 
numerous scripts (.pl, .pm) to install.  Java was much easier, I could ship 
a single .jar file that included the entire compiled code of the 
application, including the web server, the jdbc drivers and my application, 
that made it easy to install the application, copy a single .jar file to a 
directory and run with a single command java -jar jarfilename.jar.  There 
can be issues if the version of java on the target system is older than 
what you expect but the same applies to perl.

Once I got in to java, I also found that much more design material was 
available in regards to object oriented development than was available in 
perl.  Topics such as design patterns are well covered in a variety of java 
books and white pages.  Many examples of Model/View/Controller (MVC) 
patterns are around in java, that didn't even seem to get discussed much in 
the perl world.  A topic associated with this is development methodologies, 
the Agile Methodologies including Extreme Programming are well supported in 
the java world with junit.  I'd be interested to hear from others who have 
used perl and Extreme Programming and what conclusions they have drawn from 
the experience.

>I haven't ever done any web applications, so I really don't know, but my 
>experience with Java is that it's large, slow, not very portable really, 
>and the database integration support just doesn't measure up to Perl's DBI 
>module, and it takes a *lot* more code to get anywhere.

Web applications are much different in java than non-web 
applications.  With non-web applications in java the java GUI is not 
pretty, your comments below about java guis that are slow and large are 
quite applicable).  With web applications, java generates the html and the 
performance isn't really an issue.  One issue in perl's favour is that the 
breadth of available libraries is much better and richer than java in 
certain areas such as generation of png charts, etc.  The newer versions of 
java (many since 1999) are much better performance wise.  The number of 
api's being released with each version of java are staggering.

Having used DBI and JDBC extensively, I can't see where java's database 
integration doesn't measure up to perl's dbi.  They are both quite similar 
to use.  I haven't looked at how to do database connection pooling in dbi 
but it is quite easy now in java with jdbc2.  It can take more code in java 
to get some things done in perl but the object orientation in java is 
better than it was in perl.

I have found it easier to make java applications portable across 
unix/Windows than perl.

>That was in 1999, maybe things have changed (but I still have to run Java 
>GUIs that are too slow and suck up 46M!!). Is there any real advantage 
>over, say Apache + mod_perl + Perl?

Overall, I would say the servlet api provides better capabilities than 
Apache + mod_perl but I believe a dedicated perl developer can build just 
as fast (if not faster) applications using perl with mod_perl.  One 
limitation with that is being tied to Apache.  With the advent of a number 
of pure java web servers, BEA, Orion, for example, being tied to apache can 
be a limitation.

I would also say that part of my choice in using java over perl in 
application development had to do with career goals.  Java has become much 
more the language of choice in the enterprise size of organisations 
compared to perl.  Organisations like IBM, Oracle, BEA, Borland and Sun 
have made significant investment in java.  For some, the fact that java is 
not open source is an issue, my answer to that, choose perl if that bothers 
you.

Perl is a really great language, it has many strengths, the same applies to 
java, I continue to use both languages and encourage others to do the 
same.  The learning curve for me was significantly larger with java 
compared to perl, yet I have several friends who took up perl on the basis 
of my ravings about it and both of them struggled with learning perl.  That 
was hard for me to understand because I found perl extremely easy to learn.

cheers

Tony