After a simple Grails application, let's create a CRUD application. Such an application allows to perform basic database operations to read table rows from the database, create new rows, and edit and delete existing rows. This blog shows how such an application can be created using Grails, hosted on built-in Jetty servlet engine and use in-memory HSQLDB database for persistence.

A follow-up entry will show how this application can be deployed in production mode on GlassFish and using MySQL database.

1. Create a Grails application
1. After Grails download and configuration, create a new application "crud" as:
   
   

   ~/testbed/grails-1.0.2/samples >grails create-app crud Welcome to Grails 1.0.2 - http://grails.org/ Licensed under Apache Standard License 2.0 Grails home is set to: /Users/arungupta/testbed/grails-1.0.2 Base Directory: /Users/arungupta/testbed/grails-1.0.2/samples Note: No plugin scripts found Running script /Users/arungupta/testbed/grails-1.0.2/scripts/CreateApp.groovy Environment set to development     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/src     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/src/java     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/src/groovy     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app/controllers     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app/services     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app/domain     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app/taglib     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app/utils     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app/views     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app/views/layouts     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app/i18n     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app/conf     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/test     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/test/unit     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/test/integration     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/scripts     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/web-app     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/web-app/js     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/web-app/css     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/web-app/images     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/web-app/META-INF     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/lib     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app/conf/spring     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app/conf/hibernate [propertyfile] Creating new property file: /Users/arungupta/testbed/grails-1.0.2/samples/crud/application.properties      [copy] Copying 2 files to /Users/arungupta/testbed/grails-1.0.2/samples/crud      [copy] Copying 2 files to /Users/arungupta/testbed/grails-1.0.2/samples/crud/web-app/WEB-INF      [copy] Copying 5 files to /Users/arungupta/testbed/grails-1.0.2/samples/crud/web-app/WEB-INF/tld      [copy] Copying 87 files to /Users/arungupta/testbed/grails-1.0.2/samples/crud/web-app      [copy] Copying 17 files to /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app      [copy] Copying 1 file to /Users/arungupta/testbed/grails-1.0.2/samples/crud      [copy] Copying 1 file to /Users/arungupta/testbed/grails-1.0.2/samples/crud      [copy] Copying 1 file to /Users/arungupta/testbed/grails-1.0.2/samples/crud [propertyfile] Updating property file: /Users/arungupta/testbed/grails-1.0.2/samples/crud/application.properties Created Grails Application at /Users/arungupta/testbed/grails-1.0.2/samples/crud

2. In your project directory, create a domain class as:
   
   

   ~/testbed/grails-1.0.2/samples/crud >grails create-domain-class state Welcome to Grails 1.0.2 - http://grails.org/ Licensed under Apache Standard License 2.0 Grails home is set to: /Users/arungupta/testbed/grails-1.0.2 Base Directory: /Users/arungupta/testbed/grails-1.0.2/samples/crud Note: No plugin scripts found Running script /Users/arungupta/testbed/grails-1.0.2/scripts/CreateDomainClass.groovy Environment set to development      [copy] Copying 1 file to /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app/domain Created  for State      [copy] Copying 1 file to /Users/arungupta/testbed/grails-1.0.2/samples/crud/test/integration Created Tests for State

   
   This creates "State.groovy" class in "grails-app/domain" directory and looks like:
   
   

   class State { }

   
   Add two fields to store state name and the corresponding abbreviation as shown below:
   
   

   class State {         String name         String abbrev }

3. Change "grails-app/conf/BootStrap.groovy" class to initialize the domain with sample data as shown below:
   
   

   class BootStrap {      def init = { servletContext ->           new State(name:"California", abbrev:"CA").save()           new State(name:"New York", abbrev:"NY").save()           new State(name:"Texas", abbrev:"TX").save()           new State(name:"Wisconsin", abbrev:"WI").save()      }      def destroy = {      } }

4. Create a new controller as:
   
   

   ~/testbed/grails-1.0.2/samples/crud >grails create-controller state Welcome to Grails 1.0.2 - http://grails.org/ Licensed under Apache Standard License 2.0 Grails home is set to: /Users/arungupta/testbed/grails-1.0.2 Base Directory: /Users/arungupta/testbed/grails-1.0.2/samples/crud Note: No plugin scripts found Running script /Users/arungupta/testbed/grails-1.0.2/scripts/CreateController.groovy Environment set to development      [copy] Copying 1 file to /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app/controllers Created Controller for State     [mkdir] Created dir: /Users/arungupta/testbed/grails-1.0.2/samples/crud/grails-app/views/state      [copy] Copying 1 file to /Users/arungupta/testbed/grails-1.0.2/samples/crud/test/integration Created ControllerTests for State

   
   This generates "grails-app/controllers/StateController.groovy" with the following content:
   
   

   class StateController {     def index = { } }

   
   Replace it with to define a scaffold:
   
   

   class StateController {     def scaffold = State }

2. Start the application using built-in Jetty Servlet engine and in-memory HSQLDB database as shown below:
   
   

   ~/testbed/grails-1.0.2/samples/crud >grails run-app Welcome to Grails 1.0.2 - http://grails.org/ Licensed under Apache Standard License 2.0 Grails home is set to: /Users/arungupta/testbed/grails-1.0.2 Base Directory: /Users/arungupta/testbed/grails-1.0.2/samples/crud Note: No plugin scripts found Running script /Users/arungupta/testbed/grails-1.0.2/scripts/RunApp.groovy Environment set to development Running Grails application.. 2008-04-18 17:26:29.962::INFO:  Logging to STDERR via org.mortbay.log.StdErrLog 2008-04-18 17:26:29.075::INFO:  jetty-6.1.4 2008-04-18 17:26:29.155::INFO:  No Transaction manager found - if your webapp requires one, please configure one. 2008-04-18 17:26:30.886:/crud:INFO:  Set web app root system property: 'crud' = [/Users/arungupta/testbed/grails-1.0.2/samples/crud/web-app/] 2008-04-18 17:26:30.886:/crud:INFO:  Initializing Log4J from [file:/Users/arungupta/.grails/1.0.2/projects/crud/resources/log4j.properties] 2008-04-18 17:26:30.945:/crud:INFO:  Initializing Spring root WebApplicationContext [0] spring.GrailsWebApplicationContext Refreshing org.codehaus.groovy.grails.commons.spring.GrailsWebApplicationContext@848dfb: display name [org.codehaus.groovy.grails.commons.spring.GrailsWebApplicationContext@848dfb]; startup date [Fri Apr 18 17:26:32 PDT 2008]; parent: org.springframework.web.context.support.XmlWebApplicationContext@cddcc3 [1] spring.GrailsWebApplicationContext Bean factory for application context [org.codehaus.groovy.grails.commons.spring.GrailsWebApplicationContext@848dfb]: org.springframework.beans.factory.support.DefaultListableBeanFactory@11f136 2008-04-18 17:26:34.655:/crud:INFO:  Initializing Spring FrameworkServlet 'grails' 2008-04-18 17:26:35.716::INFO:  Started SelectChannelConnector@0.0.0.0:8080 Server running. Browse to http://localhost:8080/crud

   
   The application is now accessible at "http://localhost:8080/crud" and looks like:
   
   
   
   
3. READ - Click on "StateController" and the following page is shown:
   
   
   
   
4. CREATE - Click on "New State" and enter the values as shown below:
   
   
   
   and click on "Create" to see the following page:
   
   
   
   
5. UPDATE & DELETE - You can click on "Edit" or "Delete" to perform U or D of CRUD or click on "State List" to view the updated list as shown below:
   
   

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Technorati: groovy grails glassfish jetty hsqldb scripting crud