Grails Goodness: Add Banner To Grails 3.1 Application

In a previous post we learned how to add a banner to a Grails 3.0 application. We used the Spring Boot support in Grails to show a banner on startup. The solution we used doesn't work for a Grails 3.1 application. We need to implement a different solution to show a banner on startup.

First of all we create a new class that implements the org.springframework.boot.Banner interface. We implement the single method printBanner and logic to display a banner, including colors:

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// File: src/main/groovy/mrhaki/grails/GrailsBanner.groovy package mrhaki.grails   import org.springframework.boot.Banner import grails.util.Environment import org.springframework.boot.ansi.AnsiColor import org.springframework.boot.ansi.AnsiOutput import org.springframework.boot.ansi.AnsiStyle   import static grails.util.Metadata.current as metaInfo   /**  * Class that implements Spring Boot Banner  * interface to show information on application startup.  */ class GrailsBanner implements Banner {       /**      * ASCCI art Grails 3.1 logo built on      * http://patorjk.com/software/taag/#p=display&f=Graffiti&t=Type%20Something%20      */     private static final String BANNER = $/   _________________    _____  .___.____       _________ ________      ____  /  _____|______   \  /  _  \ |   |    |     /   _____/ \_____  \    /_   | /   \  ___|       _/ /  /_\  \|   |    |     \_____  \    _(__  <     |   | \    \_\  \    |   \/    |    \   |    |___  /        \  /       \    |   |  \______  /____|_  /\____|__  /___|_______ \/_______  / /______  / /\ |___|         \/       \/         \/            \/        \/         \/  \/          /$       @Override     void printBanner(             org.springframework.core.env.Environment environment,             Class<?> sourceClass,             PrintStream out) {           // Print ASCII art banner with color yellow.         out.println AnsiOutput.toString(AnsiColor.BRIGHT_YELLOW, BANNER)           // Display extran infomratio about the application.         row 'App version', metaInfo.getApplicationVersion(), out         row 'App name', metaInfo.getApplicationName(), out         row 'Grails version', metaInfo.getGrailsVersion(), out         row 'Groovy version', GroovySystem.version, out         row 'JVM version', System.getProperty('java.version'), out         row 'Reloading active', Environment.reloadingAgentEnabled, out         row 'Environment', Environment.current.name, out                   out.println()     }       private void row(final String description, final value, final PrintStream out) {         out.print AnsiOutput.toString(AnsiColor.DEFAULT, ':: ')         out.print AnsiOutput.toString(AnsiColor.GREEN, description.padRight(16))         out.print AnsiOutput.toString(AnsiColor.DEFAULT, ' :: ')         out.println AnsiOutput.toString(AnsiColor.BRIGHT_CYAN, AnsiStyle.FAINT, value)     }   }

Next we must override the GrailsApp class. We override the printBanner method, which has no implementation in the GrailsApp class. In our printBanner method we use GrailsBanner:

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// File: src/main/groovy/mrhaki/grails/BannerGrailsApp.groovy package mrhaki.grails   import grails.boot.GrailsApp import groovy.transform.InheritConstructors import org.springframework.core.env.Environment   @InheritConstructors class BannerGrailsApp extends GrailsApp {           @Override     protected void printBanner(final Environment environment) {         // Create GrailsBanner instance.         final GrailsBanner banner = new GrailsBanner()           banner.printBanner(environment, Application, System.out)     }       }

Finally in the Application class we use BannerGrailsApp instead of the default GrailsApp object:

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// File: grails-app/init/mrhaki/grails/Application.groovy package mrhaki.grails   import grails.boot.config.GrailsAutoConfiguration   class Application extends GrailsAutoConfiguration {     static void main(String[] args) {         final BannerGrailsApp app = new BannerGrailsApp(Application)         app.run(args)     } }

When we start our Grails application on a console with color support we see the following banner:

Written with Grails 3.1.8.