Launching an application using Gradle

Typically, the very first step of creating any application is to have a basic skeleton, which can be immediately launched as is. As the Spring Boot starter has created the application template for us already, all we have to do is extract the code, build, and execute it. Now let's go to the console and launch the app with Gradle.

How to do it…

1. Change in the directory where the bookpub.zip archive was extracted from and execute the following command from the command line:

   $ ./gradlew clean bootRun
   

Tip

If you don't have gradlew in the directory, then download a version of Gradle from https://gradle.org/downloads or install it via homebrew by executing brew install gradle. After Gradle is installed, run gradle wrapper to get the Gradle wrapper files generated. Another way is to invoke gradle clean bootRun in order to achieve the same results.

The output of the preceding command will be as follows:

…
  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::  (v1.2.3.BUILD-SNAPSHOT)

2015-03-09 23:18:53.721 : Starting BookPubApplication on mbp with PID 43850 
2015-03-09 23:18:53.781 : Refreshing org.springframework.context.annotation.Annotatio
2015-03-09 23:18:55.544 : Building JPA container EntityManagerFactory for persistence 
2015-03-09 23:18:55.565 : HHH000204: Processing PersistenceUnitInfo [name: default	
2015-03-09 23:18:55.624 : Hibernate Core {4.3.8.Final}
2015-03-09 23:18:55.625 : HHH000206: hibernate.properties not found
2015-03-09 23:18:55.627 : HHH000021: Bytecode provider name : javassist
2015-03-09 23:18:55.774 : HCANN000001: Hibernate Commons Annotations {4.0.5.Final
2015-03-09 23:18:55.850 : HHH000400: Using dialect: org.hibernate.dialect.H2Dialect
2015-03-09 23:18:55.902 : HHH000397: Using ASTQueryTranslatorFactory
2015-03-09 23:18:56.094 : HHH000227: Running hbm2ddl schema export
2015-03-09 23:18:56.096 : HHH000230: Schema export complete
2015-03-09 23:18:56.337 : Registering beans for JMX exposure on startup
2015-03-09 23:18:56.345 : Started BookPubApplication in 3.024 seconds (JVM running...
2015-03-09 23:18:56.346 : Closing org.springframework.context.annotation.AnnotationC..
2015-03-09 23:18:56.347 : Unregistering JMX-exposed beans on shutdown
2015-03-09 23:18:56.349 : Closing JPA EntityManagerFactory for persistence unit 'def…
2015-03-09 23:18:56.349 : HHH000227: Running hbm2ddl schema export
2015-03-09 23:18:56.350 : HHH000230: Schema export complete
BUILD SUCCESSFUL
Total time: 52.323 secs

How it works…

As we can see, the application started just fine, but as we didn't add any functionality or configure any services, it terminated right away. From the startup log, however, we do see that the autoconfiguration did take place. Let's take a look at the following lines:

Building JPA container EntityManagerFactory for persistence unit 'default'
HHH000412: Hibernate Core {4.3.8.Final}
HHH000400: Using dialect: org.hibernate.dialect.H2Dialect

This information tells us that because we added the jdbc and data-jpa starters, the JPA container was created and will use Hibernate 4.3.8.Final to manage the persistence using H2Dialect. This was possible because we had the right classes in the classpath.

Tip

Downloading the example code

You can download the example code files for all Packt books you have purchased from your account at http://www.packtpub.com. If you purchased this book elsewhere, you can visit http://www.packtpub.com/support and register to have the files e-mailed directly to you.