Thursday, May 27, 2010

Using Play! precompiled classes

If you want to run Play! in PROD mode, after precompiling your code, you probably noticed that Play.usePrecompiled is set to false and doesn't change. This causes your code to be compiled when the PROD server starts.
I read somewhere that in the GAE module it's set to true.

Well, what if I want to deploy my Play! application without the sources and use my precompiled classes?
This only requires setting Play.usePrecompiled to true, writing a new module for this seems too much.
I thought the plugins architecture was the way to go, setting this in the onLoad() method, but without setting usePrecompiled Play! can not invoke my plugin.

I found an acceptable hack.
One of the first thing Play! does in the init() method is invoke initStaticStuff(), this method searches for files named "play.static" in the classpath, each line in the files must be a Java class name, and Class.forName() is invoked for each such class.
This doesn't do much but I can set the usePrecompiled value to true in a static initializer block.
I use a JVM property ("usePrecompile") to control the use of the precompiled classes.
I wrote a new class
package org.oded;

import play.Play;

public class Bootstrap {
 static {
  Play.usePrecompiled = Boolean.getBoolean( "usePrecompile" ) && Play.getFile( "precompiled" ).exists();

I added a "play.static" file to my conf directory, the file has one line "org.oded.Bootstrap".

In addition I updated my build script, the one that invokes "play precompile", also creates a jar file in myserver/lib with only the Bootstrap file in it.

This is probably not the use that was intended for this hook, but it works.

Wednesday, May 12, 2010

Creating a log4j logger in an Eclipse template

private static Logger logger = Logger.getLogger( MyClass.class );
Are you tired of writing the same line of code over and over again?

No more!

Using the Eclipse templates you can generate this code easily.
Create the template by clicking Window -> Preferences -> Java -> Editor -> Templates -> New

Enter the template name

Enter the pattern
private static Logger logger = Logger.getLogger( ${enclosing_type}.class );
This pattern also takes care of the import statement.

Creating an Eclipse template

Now see it in action: