สร้าง java project เล็กๆด้วย Gradle

> mkdir demo-java
> cd demo-java

> gradle init

Select type of project to generate:
  1: basic
  2: application
  3: library
  4: Gradle plugin
Enter selection (default: basic) [1..4] 2

Select implementation language:
  1: C++
  2: Groovy
  3: Java
  4: Kotlin
  5: Scala
  6: Swift
Enter selection (default: Java) [1..6] 

Split functionality across multiple subprojects?:
  1: no - only one application project
  2: yes - application and library projects
Enter selection (default: no - only one application project) [1..2] 

Select build script DSL:
  1: Groovy
  2: Kotlin
Enter selection (default: Groovy) [1..2] 

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

Project name (default: demo-java): 
Source package (default: demo.java): 

> Task :init
Get more help with your project: https://docs.gradle.org/6.8.3/samples/sample_building_java_applications.html

BUILD SUCCESSFUL in 22s
2 actionable tasks: 2 executed

.
├── app
│   ├── build
│   │   ├── classes
│   │   │   └── java
│   │   │       └── main
│   │   │           └── demo
│   │   │               └── java
│   │   │                   └── App.class
│   │   ├── generated
│   │   │   └── sources
│   │   │       ├── annotationProcessor
│   │   │       │   └── java
│   │   │       │       └── main
│   │   │       └── headers
│   │   │           └── java
│   │   │               └── main
│   │   └── tmp
│   │       └── compileJava
│   │           └── source-classes-mapping.txt
│   ├── build.gradle
│   └── src
│       ├── main
│       │   ├── java
│       │   │   └── demo
│       │   │       └── java
│       │   │           └── App.java
│       │   └── resources
│       └── test
│           ├── java
│           │   └── demo
│           │       └── java
│           │           └── AppTest.java
│           └── resources
├── gradle
│   └── wrapper
│       ├── gradle-wrapper.jar
│       └── gradle-wrapper.properties
├── gradlew
├── gradlew.bat
└── settings.gradle

/*
 * This Java source file was generated by the Gradle 'init' task.
 */
package demo.java;

public class App {
    public String getGreeting() {
        return "Hello World!";
    }

    public static void main(String[] args) {
        System.out.println(new App().getGreeting());
    }
}

> gradle run

> Task :app:run
Hello World!

// https://mvnrepository.com/artifact/commons-codec/commons-codec
implementation group: 'commons-codec', name: 'commons-codec', version: '1.15'

dependencies {
    // Use JUnit test framework.
    testImplementation 'junit:junit:4.13'

    // This dependency is used by the application.
    implementation 'com.google.guava:guava:29.0-jre'

    implementation group: 'commons-codec', name: 'commons-codec', version: '1.15'
}

package demo.java;

import org.apache.commons.codec.binary.Hex;


public class App {
    public static void main(String[] args) {
        System.out.println(Hex.encodeHexString("Hello World".getBytes()));
    }
}

> gradle run

> Task :app:run
48656c6c6f20576f726c64

BUILD SUCCESSFUL in 1s
2 actionable tasks: 2 executed