====== Java ======

===== Gradle =====

==== Initializing a Gradle project ====

<code>
$ mkdir TestGradle
$ cd $_
$ gradle init --type java-application --dsl groovy

Enter target Java version (min: 7, default: 21):

Project name (default: TestGradle):

Select application structure:
  1: Single application project
  2: Application and library project
Enter selection (default: Single application project) [1..2] 1

Select test framework:
  1: JUnit 4
  2: TestNG
  3: Spock
  4: JUnit Jupiter
Enter selection (default: JUnit Jupiter) [1..4] 1

Generate build using new APIs and behavior (some features may change in the next minor release)? (default: no) [yes, no] yes


> Task :init
To learn more about Gradle by exploring our Samples at https://docs.gradle.org/8.8/samples/sample_building_java_applications.html

BUILD SUCCESSFUL in 8s
1 actionable task: 1 executed
$

gradle build
gradle run
</code>

To pass arguments, use the "--args=" command line option like this: "gradle run --args='arg1 arg2 arg3'"

==== Spring Boot Console Application ====

<code>
//
// app/build.gradle
//

plugins {
    id 'application'
    id "org.springframework.boot" version "3.3.5"
    id 'io.spring.dependency-management' version '1.1.6'
}

repositories {
    mavenCentral()
}

dependencies {
    implementation libs.guava
    implementation 'org.springframework.boot:spring-boot-starter'
}

java {
    toolchain {
        languageVersion = JavaLanguageVersion.of(21)
    }
}

application {
    mainClass = 'org.example.App'
}

//
// app/src/main/java/org/example/App.java
//

package org.example;

import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import java.util.logging.Logger;
import org.springframework.stereotype.Component;
import org.springframework.beans.factory.annotation.Autowired;

@Component
class MyComponent {
  public void doSomething() { System.out.println("Moo"); }
}

@SpringBootApplication
public class App implements CommandLineRunner {
  private static Logger log = Logger.getLogger(App.class.getName());

  @Autowired
  MyComponent myComponent;

  public static void main(String[] args) {
    SpringApplication.run(App.class, args);
  }

  @Override
  public void run(String... args) {
    log.info("Running.");
    myComponent.doSomething();
  }
}
</code>

A Command Line Runner application can take advantage of auto-wiring by Spring.

==== Gradle Jobs with Different gradle-user-home ====

<code>
gradle -g $PWD build
gradle -g $PWD run --args='something'
</code>

This is to work around the "Timeout waiting to lock artifact cache" and "Starting a Gradle Daemon, 1 busy and 1 stopped Daemons could not be reused, use --status for details" (Also try "gradle --stop" and "gradle --status").

Setting the gradle-user-home creates the following subdirectories in the specific directory: caches, daemon, jdks, native, notification