Spicy Spring: Create New Projects From a URL

Posted on March 17, 2016 by mrhaki

To quickly start with a Spring project we can use the website start.spring.io. Via a user interface we can set project properties and at the end we have a project archive (Zip or gzipped Tar file) or build file (pom.xml or build.gradle). We can also directory access an URL to create the output files and we set the properties via request parameters. This way you can share a link with someone and if they click on it they will download the generated project archive or build files.

Continue reading →

Gradle Goodness: Lazy Task Properties

Posted on March 9, 2016 by mrhaki

When we create our own custom tasks we might need to support lazy evaluation of task properties. A Gradle build has three phases: initialisation, configuration and execution. Task properties can be set during the configuration phase, for example when a task is configured in a build file. But our task can also evaluate the value for a task property at execution time. To support evaluation during execution time we must write a lazy getter method for the property. Also we must define the task property with def or type Object. Because of the Object type we can use different types to set a value. For example a Groovy Closure or Callable interface implementation can be used to execute later than during the configuration phase of our Gradle build. Inside the getter method we invoke the Closure or Callable to get the real value of the task property.

Continue reading →

Gradle Goodness: Apply External Script With Plugin Configured Through Buildscript

Posted on November 10, 2015 by mrhaki

Suppose we use the Gradle apply from: statement to import another Gradle build file into our build file. The external build file uses a Gradle plugin that needs a buildscript block to define the classpath configuration with the classes needed for the plugin. We cannot use the plugin id inside our external build script to use it, but we must use the type of the plugin. Otherwise Gradle cannot resolve the plugin from the main build file.

Continue reading →

Gradle Goodness: Setting Global Properties For All Gradle Builds

Posted on October 29, 2015 by mrhaki

To define project properties outside the Gradle build file, we can define them in a file gradle.properties in our project directory. If we want to define property values that are used by all Gradle builds we can create a file gradle.properties in the GRADLE_USER_HOME directory. By default this is in the USER_HOME/.gradle directory.

Continue reading →

Gradle Goodness: Download Javadoc Files For Dependencies In IDE

Posted on October 27, 2015 by mrhaki

Gradle has an idea and eclipse plugin that we can use to configure IntelliJ IDEA and Eclipse project files. When we apply these plugins to our project we get extra tasks to generate and change project files. Inside our Gradle build file we get new configuration blocks to specify properties or invoke methods that will change the configuration files. One of the nice things to add is to let the IDE download Javadoc files for dependencies in our Java/Groovy projects. By default the sources for a dependency are already downloaded and added to the project, but Javadoc files are not downloaded.

Continue reading →

Grails Goodness: Run Gradle Tasks In Grails Interactive Mode

Posted on October 20, 2015 by mrhaki

To start Grails in interactive mode we simply type grails on the command line. This starts Grails and we get an environment to run Grails commands like compile and run-app. Since Grails 3 the underlying build system has changed from Gant to Gradle. We can invoke Gradle tasks in interactive mode with the gradle command. Just like we would use Gradle from the command line we can run the same tasks, but this time when Grails is in interactive mode. Grails will use the Gradle version that belongs to the current Grails version.
We even get TAB completion for Gradle tasks.

Continue reading →

Spicy Spring: Java System Properties As Configuration Properties With Spring Boot

Posted on September 30, 2015 by mrhaki

In a previous post we learned that configuration property values can be passed via environment variables. With Spring Boot we can also pass the values using Java system properties. So if we have a property sample.message then we can use -Dsample.message=value to pass a value when we run the application. If we use the Spring Boot Gradle plugin we must reconfigure the bootRun task to pass Java system properties from the command-line.

Continue reading →

Gradle Goodness: Pass Java System Properties To Java Tasks

Posted on September 29, 2015 by mrhaki

Gradle is of course a great build tool for Java related projects. If we have tasks in our projects that need to execute a Java application we can use the JavaExec task. When we need to pass Java system properties to the Java application we can set the systemProperties property of the JavaExec task. We can assign a value to the systemProperties property or use the method systemProperties that will add the properties to the existing properties already assigned. Now if we want to define the system properties from the command-line when we run Gradle we must pass along the properties to the task. Therefore we must reconfigure a JavaExec task and assign System.properties to the systemProperties property.

Continue reading →

Gradle Goodness: Getting More Help For a Task

Posted on September 28, 2015 by mrhaki

To see which tasks are available for a Gradle project we can invoke the tasks task. With this task all tasks are printed to the console with their description. To get more information about a specific task we can use the Gradle help task with the command-line option --task followed by the task name. Gradle prints out the path, type, description, group and optional options for the task.

Continue reading →

Spicy Spring: Setting Configuration Properties Via Environment Variables

Posted on September 25, 2015 by mrhaki

Spring Boot has many options for externalising the configuration of our application. One of the options it to use OS environment variables. We need to follow certain rules to name the environment variable and then Spring Boot will use the value of variable to set a configuration property. The property name must be in uppercase and any dots need to be replaced with underscores. For example the configuration property sample.message is set with the environment variable SAMPLE_MESSAGE. This feature can be useful in a continuous integration environment where we can set environment variables or just when developing locally. The nice thing is that this also works when we use the Spring Boot Gradle plugin. The environment variables are passed on to the Java process that the bootRun task starts.

Continue reading →