Friday, January 20, 2012

Grails Codec file location and extension

If you are just beginning out in Grails development, the creation of custom codecs can greatly increase productivity. Codecs help you code/decode (funny that) strings. Grails ships with a bunch of them already, but when you feel like you want to create you own, greate a groovy class file (extension .groovy), with the name ending in "Codec" in your projects graips-app/utils folder. Remember that if you want to place these files in packages, you will need to create the additional folder structure to match the package structure. A sample codec structure is shown below. This file would be in the folder grails-app/utils/org/mycompany/:

package org.mycompany
import /* imports here */

class SampleCodec{
  static encode = { str ->
   /* Coding data goes here */

static decode = { str ->
   /* Decoding data goes here */


Once you start your grails app, Spring will inject the methods encodeAsSample() and decodeSample() to the Java.lang.String class.

Start creating custom hash codes for your passwords now!

Wednesday, January 18, 2012

JMX and Grails

Developing on windows can sometimes really be a pain. I had found documentation all over the web as to where to place my JVM arguments to make grails accept remote JMX connections while developing in eclipse. Most have you modifying $GRAILS_HOME/bin/grails.bat but I was noticing in Java Visual VM (great tool by the way) that the VM arguments were not changing.

In one of those 'the answer is simple stupid' moments - some clarity was given to me by this page of documentation:

By adding the following string the run configuration for my Grails project: -Djava.rmi.server.hostname=<yourHostIPHere>
[Note this is obviously not a production setting, you will NEED AUTHENTICATION in production]

I was able to get jconsole to connect to the remote process. Of course local connections had never been a problem as JMX is enabled locally by default.

For anyone curious, the run configuration for a tutorial project is shown below.

A run configuration for JMX with Grails on Windows Eclipse.