Archive: February 2024

Gradle Goodness: Using System Properties Lazily

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Hubert Klein Ikkink

It is good practice in Gradle to use lazy configuration. This makes builds faster as only configuration values are evaluated when needed. We should try to not let Gradle spend time on evaluating configuration values that will not be used. For example tasks that are not executed could still be configured by Gradle. If we make sure the configuration of these tasks is lazy we can save time.

Gradle gives us a lazy way to get the value of a Java system property. In our build script we can use the providers property of type ProviderFactory and the method systemProperty(String). This method returns a Provider<String> instance that can be used to get the value of a system property in a lazy way. The method systemProperty can also be used with a Provider<String> argument.

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Gradle Goodness: Using Environment Variables Lazily

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Hubert Klein Ikkink

It is good practice in Gradle to use lazy configuration. This makes builds faster as only configuration values are evaluated when needed. We should try to not let Gradle spend time on evaluating configuration values that will not be used. For example tasks that are not executed could still be configured by Gradle. If we make sure the configuration of these tasks is lazy we can save time.

Gradle gives us a lazy way to get the value of an environment variable. In our build script we can use the providers property of type ProviderFactory and the method environmentVariable(String). This method returns a Provider<String> instance that can be used to get the value of an environment variable in a lazy way.

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Kotlin Discovered: Variance (again)

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Jacob van Lingen

You never touched Groovy, nor did you jump on the Scala train. Clojure never attracted you; and you heard about Ceylon long after the language had already died. You are one of those old-fashioned Java folks! But now, after all those years, you want to join the cool Kotlin kids. So, where to start? Let’s discover the language together by decompiling it to Java code. Today: The things we tend to forget!

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IntelliJ HTTP Client: Accessing Environment Variables In JavaScript

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Hubert Klein Ikkink

When we use the IntelliJ HTTP Client we can write JavaScript for the pre-request and response handlers. If we want to access an environment variable in JavaScript we can use request.environment.get(string). The argument for the get function is the name of the environment variable we want to get the value for. Environment variables can be defined in the file http-client.env.json or in http-client.private.env.json.

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IntelliJ HTTP Client: Using In-Place Variables

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Hubert Klein Ikkink

The built-in IntelliJ HTTP Client is very useful for testing HTTP requests and responses. If we want to define a variable in our .http file that is only used in this file and will not change per environment we can define it using the following syntax: @<variable name> = variable value. The variable is an in-place variable and the scope of the variable in the current .http file. The variable is immutable and can only be defined with a value once and cannot be overwritten. To refer to the variable we use the syntax {{}}.

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GPU programming, a high level overview

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Silvian Bensdorp

Over the last year, there has been quite some fuss over using GPU’s for other tasks than gaming. News stories about AI and cryptocurrency mining requiring vast amounts of GPU’s; product shortages in the consumer gaming market are just a few to name. Share prices for semiconductor design companies, particularly Nvidia, have been soaring. Yet, on the other hand, there is little understanding in the general software development community as to how these techniques work, what class of problems they can solve more effectively, and how and when to use them.

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Gradle Goodness: Continuous Testing For Java Projects

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Hubert Klein Ikkink

The command line option --continuous or the short version -t enables Gradle’s continous build. For a continuous build Gradle will keep on running and will re-execute the tasks we invoked if the input or of the input of one of the depended tasks has changed. For a project with the java plugin we can use this option for the test task. Gradle will run the test task and after the task has been executed Gradle will wait for any changes in the input of the task. This means if we change our Java test code in src/test/java and save the source file Gradle will re-execute the test task and show the output. But also if the input of other tasks changes, that the test task depends on, the test is re-executed. So also changes in source files in our src/main/java directory will trigger a re-execute of the test task, because the test task depends on the compileJava task, and the compileJava task has the src/main/java directory as input.

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Gradle Goodness: Java Toolchain Configuration Using User Defined Java Locations

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Hubert Klein Ikkink

With the java plugin we can configure a so-called Java toolchain. The toolchain configuration is used to define which Java version needs to be used to compile and test our code in our project. The location of the Java version can be determined by Gradle automatically. Gradle will look at known locations based on the operating system, package managers, IntellIJ IDEA installations and Maven Toolchain configuration.

But we can also define the locations of our Java installations ourselves using the project property org.gradle.java.installations.paths. We provide the paths to the local Java installations as a comma separated list as value for this property. When we set this property we can also disable the Gradle toolchain detection mechanism, so only the Java installations we have defined ourselves are used. To disable the automatic detection we set the property org.gradle.java.installations.auto-detect to false. If we leave the value to the default value true, then the locations we set via org.gradle.java.installations.paths are added to the Java installations already found by Gradle.

The property org.gradle.java.installations.paths is a project property we can set via the command line, but we can also set it in the gradle.properties file in our GRADLE_USER_HOME directory. Then the values we define will be used by all Gradle builds on our machine.

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Gradle Goodness: Using Maven Toolchains Configuration For Gradle Java Toolchain Resolution

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Hubert Klein Ikkink

When we apply the Java plugin to our Gradle project we can configure which Java version we want to use for compiling our source code and running our tests using a toolchain configuration. The benefit of having a toolchain configuration is that we can use a different Java version for compiling and running our code than the Java version that is used by Gradle to execute the build. Gradle will look for that Java version on our local computer or download the correct version if it is not available. To search for a local Java installation Gradle will look for operating system specific locations, installations by package managers like SKDMAN! and Jabba, IntelliJ IDEA installations and Maven Toolchain specifications. Maven Toolchain specifications is an XML file describing the location of local Java installation. Each Java installation is described by a version and optional vendor it provides and the location of the installation. Maven uses this information to find the correct Java installation when the maven-toolchain-plugin is used in a Maven project. But Gradle can also utilize Maven Toolchain specifications to find local Java installations. This can be useful when we have to work on multiple projects where some use Maven and others use Gradle. We can place the Maven Toolchain specification file in our Maven home directory. This is also the default place where Gradle will look, but we can use a project property to override this location.

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