Step 1: Grails Installation, Running and Debugging an application

Before installing Grails 3.x you will need as a minimum a Java Development Kit (JDK) installed version 1.7 or above. Download the appropriate JDK for your operating system, run the installer, and then set up an environment variable called JAVA_HOME pointing to the location of this installation.

export JAVA_HOME=/Library/Java/Home
export PATH="$PATH:$JAVA_HOME/bin"

On Windows you would have to configure these environment variables in My Computer/Advanced/Environment Variables

For manual installation follow these steps:

·       Download a binary distribution of Grails and extract the resulting zip file to a location of your choice

·       Set the GRAILS_HOME environment variable to the location where you extracted the zip

o  On Unix/Linux based systems this is typically a matter of adding something like the following export GRAILS_HOME=/path/to/grails to your profile

o  On Windows this is typically a matter of setting an environment variable under My Computer/Advanced/Environment Variables

·       Then add the bin directory to your PATH variable:

o  On Unix/Linux based systems this can be done by adding export PATH="$PATH:$GRAILS_HOME/bin" to your profile

o  On Windows this is done by modifying the Path environment variable under My Computer/Advanced/Environment Variables

If Grails is working correctly you should now be able to type grails -version in the terminal window and see output similar to this:

Grails version: 3.2.10

You have familiar with Composer and need to install Composer. If not, please see https://getcomposer.org and install composer. After installing composer, go to your htdocs folder and open terminal and run the command To create a Grails application you first need to familiarize yourself with the usage of the grails command which is used in the following manner:

grails <<command name>>

Run create-app to create an application:

grails create-app helloworld
   

Running and Debugging an Application

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Grails applications can be run with the built in Tomcat server using the run-app command which will load a server on port 8080 by default:

grails run-app

You can specify a different port by using the -port argument:

grails run-app -port=8090
When you run the app, it will view in the browse with http://localhost:8090 URL. 
If you want run again, that time, you need to stop with port as like 
grails stop-app -port=8090
and execute run command. 

For more http://docs.grails.org/latest/guide/gettingStarted.html