Raible Designs

How to run Tomcat on Port 80

I've had people ask me how to run Tomcat on Port 80 before (as a non-root user). I've never had an answer until now. Today I found that Holger Klawitter has a solution using Kernel space port forwarding. I don't have a need to try this at the moment, but if someone is using it - please share your experiences.

As an FYI, Tomcat 5 will use commons-daemon making this much easier to do. Also, the first Beta of Tomcat 5 (5.0.9) has been released.

PHP vs. Java - which is better?

I have a former client that has a customer. This customer asked them - "so when are you migrating from Java to PHP?" So evidently this person has the impression that the next wave of web applications will be written in PHP. My former client has asked me to provide an answer for their customer. If I translate it, I think they mean to ask "what is different between Java and PHP and why should we use Java over PHP." Here are my opinions - please add yours as you see fit. I must admit I don't know a whole lot about PHP, except that it's widely popular among the Linux/Apache/MySQL crowd and that it's similar to ASP in it's lack of a MVC architecture (yes, I know about the PHP MVC project).

• I think Java is more of an industry standard, whereas PHP seems to be popular among hackers and hobbyists.
• Java provides better separation of layers - key for testability. PHP has all the code embedded in the page, so you have to run it through a browser to test if database connections work (for instance).
• Java is more scalable.
• More folks know Java and it's easier to qualify someone's Java skills. How do you test someone knows PHP? Is there a certification?
• More for-profit organizations use it.

If you're a Java or a PHP-lover, I'd love to hear your opionions (facts are always better). I'm going to point my client to this post, so keep it clean.

MySQL Problem: No operations allowed after connection closed

I asked the following question on the Hibernate Forums, but thought I'd put it here to see if anyone can help.

I'm using the open-session-in-view pattern and getting the following error at random:

2003-08-21 07:00:08,873 WARN [Thread-27] JDBCExceptionReporter.logExceptions(38)
    | SQL Error: 0, SQLState: 08003
2003-08-21 07:00:08,874 ERROR [Thread-27] JDBCExceptionReporter.logExceptions(46
    ) | No operations allowed after connection closed
2003-08-21 07:00:08,875 ERROR [Thread-27] JDBCException.(37) | Could not execute
    query java.sql.SQLException: No operations allowed after connection closed
at com.mysql.jdbc.Connection.checkClosed(Connection.java:2497)
at com.mysql.jdbc.Connection.prepareStatement(Connection.java:1287)
at com.mysql.jdbc.Connection.prepareStatement(Connection.java:1267)
at org.apache.commons.dbcp.DelegatingConnection.prepareStatement
    (DelegatingConnection.java:187)
at net.sf.hibernate.impl.SessionFactoryImpl.getPreparedStatement
    (SessionFactoryImpl.java:537)
at net.sf.hibernate.impl.BatcherImpl.prepareQueryStatement(BatcherImpl.java:56)
at net.sf.hibernate.loader.Loader.prepareQueryStatement(Loader.java:482)
at net.sf.hibernate.loader.Loader.doFind(Loader.java:136)
at net.sf.hibernate.loader.Loader.find(Loader.java:620)

I've used my same ServiceLocator.java class for the past 6 months on a couple of different projects (MySQL and Oracle), with no issues. But now I've developed a new app for a new client, and this error is popping up a LOT. Any ideas? I'm only closing the connection after my doFilter() method in a Filter.

It doesn't happen at all on my Windows XP machine (I've never seen the error). Only on Linux.

uname -a gives me:

Linux kgb08 2.4.20-8bigmem #1 SMP Thu Mar 13 17:32:29 EST 2003 i686 i686 i386 GNU/Linux

Tomcat 4.1.27, MySQL 4.0.13-Max-log, JDBC Driver mysql-connector-java-3.0.8-stable-bin.jar.

I've also seen it happen on MySQL 3.23.56, but now I can't seem to reproduce it.

Any ideas?

NewsMonster 1.0 and Mozilla Application Development

I got a couple of treats from the XUL Announce mailing list this morning:

Kevin A. Burton (of Apache Jetspeed fame) has released NewsMonster 1.0 - a cross-plattform weblog manager with a brain - that runs inside Mozilla 1.0 (Netscape 7.0 or greater) on OS X, Linux, or Windows and showcases the power of XUL and Java.

Too bad it doesn't run on Mozilla Firebird. Oh well, I use NetNewsWire and believe it's the best aggregator out there.

O'Reilly has published an in-depth look at Mozilla's new roadmap titled "The Future of Mozilla Application Development" by David Boswell and Brian King.

If I could instantly learn anything right now, it would be XUL, Velocity and WebWork - in that order. I don't know what good this knowledge would do me, but it sure would be nice to learn stuff w/o even trying.

[OS X] Java 1.4.1 Update DP102

While looking for a webcast for Apple's Worldwide Developers Conference, I found that a new version of JDK 1.4 was released yesterday. I doubt I'll install it - especially since I'll have to reinstall OS X to cleanly remove the build. Also, the part about "don't install this on a system with critical data" is a little discouraging - especially when I haven't experienced any bugs in the current JDK 1.4 build I'm running.

Summary: This seed consolidates a number of recent bug fixes to Java 1.4.1 and includes the changes to Java 1.3.1 from the recent Java Oracle bug fix release. The purpose of this seed is to expose the Java 1.4.1 changes to a broad sample of real-world code. While DP101 has undergone only limited testing, it is based on Apple's latest internal builds of Java, which are tested continously.

Warnings: This build has received limited testing and comes with no support. Do not install this on a system with critical data. This build installs over both Java 1.3.1 and Java 1.4.1; you will need to reinstall Mac OS X to cleanly remove this build and revert to an earlier versions of Java. This build is for evaluation purposes only, to determine if critical bugs have been addressed. You cannot distribute this build in any way.

RE: Eclipse 3.0 M1 is out!

Here is a link to all the cool new features in this release! You can download from here. [A Cup of Joe]

The upgrade-happy developer in me can't help but click the download link. The New and Noteworthy page (near the bottom) notes many improvements to Eclipse on the Mac. I'd really love it if Eclipse was fast on OS X and Apple released OS X on Intel. I really dig the OS, just not the speed of the hardware.

The Pragmatic Programmer

I began reading The Pragmatic Programmer this morning. I bought the book after hearing that it was Erik Hatcher's favorite technical book. Since Erik's Java Development with Ant was my favorite technical book - I figured this was a good recommendation. I've read one chapter and I'm loving it. This book will inspire me to be a better programmer - I can already tell.

I don't do nearly enough reading - too much blogging and OS development. So I'm going to try to read more - as David and Andrew recommend - at least one book a month. Actually, I'm going to shoot for two books per month - one technical and one non-technical. I'd compare this book to Rich Dad, Poor Dad, which I think is a great book for motivating good financial health. I read that bad boy last week in 2 hours!

Hibernate 2.0 Final this weekend?

From Gavin on the hibernate-devel mailing list:

I plan to release Hibernate 2.0 final this weekend.

It would be nice if, at the same time, we have all the other "bits" built
and available for download:

* a special XDoclet build (I need to clear this with xdoclet team)
* avalon wrapper
* tools package (mainly for the sake of CodeGenerator)
* middlegen plugin (DONE)

The XDoclet team has also been trying to get out a new release - they don't seem to be having much luck though. That's the problem with these open source projects - they take too much time, with little or no ROI for the developer(s). I dream of a day that the company I work for actually pays me to work on Open Source projects. Maybe I just need a new client for Raible Designs, and then I'll just pay myself to work on OS!

Anthill and Maven

I did a little more research this morning - this time trying to find out if Anthill could play nicely with Maven. Here is the answer I received from the anthill mailing list:

We've recently implemented a Maven builder for Anthill Pro -- it's not 
released yet but will be part of version 2.1.

We will probably implement a Maven builder for Anthill OS sometime soon 
as well.

In the meantime, check out how some people have gotten Maven builds to 
work with Anthill in the past -- 

http://lists.urbancode.com/pipermail/anthill/2002-December/000543.html

Cool! Thanks Maciej!

DHCP and Dynamic DNS on Red Hat

I found a great howto today for setting up DHCP and Dynamic DNS server on Red Hat 8.0. It literally took me about 5 minutes to get it installed and running. 5 minutes later, I had all my machines (WinXP, Win2K, OS X, Linksys Print Server) connected and working. Very slick!

Even better is I did it with Red Hat 9, which I downloaded last weekend and installed lazily over a few days. The upgrade from 8.0 was like butter. I like Void Main's Red Hat Tips so much, I'm tempted to mirror them in hopes this URL won't go away. But for now, I'll have faith and hope it's a true permalink. Hope you don't mind that I've stuffed this under my Java category - just doesn't seem fit for General.