Build and Release Management » ANT

How to Escape {“‘&} Characters in ANT

admin — Fri, 12 Feb 2010 01:23:56 +0000

How exactly do you escape special characters from ANT? Say if you need to add extra ” quotation characters within a property which already has a set of quotes?

Here’s how to do it — use XML Character entity references:

For > use >

For < use <

For “ use "

For & use &

For ‘ use '
Any other characters you need? Drop me a line..

WebLogic’s wlappc ANT Task Compilation Freezing/Hanging Errors

admin — Sun, 17 May 2009 09:38:15 +0000

Wow. This little problem was extremely tricky to detect — mainly due to WebLogic’s wlappc ANT Task’s poor documentation. In one of the projects I’m working on, there is a need to pre-compile WebLogic JSP so it will be much faster during deployment/runtime and we can catch any potential errors early. Previously, this step of the compilation has never given us any problem until when it decides to act up and freezes or hangs certain builds. However, it was never an issue since restarting the build usually fixes it.

That is, until recently when the freezing/hanging started to happen on a consistent basis. Here’s the snippet of the ANT Task:

The ANT output during build time is this and is where it freezes:

[wlappc] [jspc] Compiling /path/to/jsp/foo.jsp

Then after searching high and low on BEA’s site, I came upon this page (Here) which describes the task in detail. I then realized I should add in idlVerbose=”true”. Once I’ve added that, this is the output I got from the build:

[wlappc] [jspc] Compiling /path/to/jsp/foo.jsp
[wlappc] WARNING: unable to get an input stream for jar:file:/path/to/some/jar/WEB-INF/lib/struts.jar!/
[wlappc] java.lang.NoClassDefFoundError: org/apache/bcelx/classfile/ClassParser
[wlappc] [...]

Muuuuch better. To fix it, now I know I need to explicitly define bcel*.jar in the classpath. Here’s the modified ANT task:

classpath=”${some.dir}/some_class.jar;
${env.ANT_HOME}/lib/bcel-5.1.jar”
verbose=”true” idlVerbose=”true”/>

Notice the difference? Yeah, that fixed it…

How To Increase Heap Size for ANT’s OutOfMemory Error using ANT_OPTS

admin — Sat, 16 May 2009 04:19:28 +0000

Ever run into an ANT compilation or ANT task related compilation OutOfMemoryError problem? This little bugger of a problem can be rather tricky to debug. You may run into this problem when you have a large collection of source files to compile (think 1000+). You may also run into this problem with the following WebLogic ANT tasks:

1. jwsc
2. wlappc (LARGE JSP Pre-Compilations)

There may be other related compilation tasks, but bottom line is the Java Heap Size is too small. To increase it, you need to add $ANT_OPTS to your environment. An overkill, but also a sure way to fix the problem can be these values:

ANT_OPTS=”-Xmx1024m -Xms512m”

This variable must be set within your build machine’s environment. When ANT executes, it automatically includes $ANT_OPTS in its execution string. I hope this little hint will solve a lot of your future headaches. I’ve been troubleshooting a similar problem on a project I’m currently working on for the past 24 hours. We went from plan a, to b, to c, to d, and started to run into a dead end and wanted to go for a temp fix by disabling pre-compilation.. until I found this root cause.

If you’re not currently using $ANT_OPTS, perhaps you should look into implementing that on your infrastructure. May end up saving you a heap of debugging time down the road.