Java Gradle入門

brew install groovy
% exec $SHELL -l
% groovy -v
Groovy Version: 4.0.7 JVM: 18.0.1.1 Vendor: Oracle Corporation OS: Mac OS X

brew install gradle

% gradle -v
Welcome to Gradle 7.6!
Here are the highlights of this release:
 - Added support for Java 19.
 - Introduced `--rerun` flag for individual task rerun.
 - Improved dependency block for test suites to be strongly typed.
 - Added a pluggable system for Java toolchains provisioning.
For more details see https://docs.gradle.org/7.6/release-notes.html
------------------------------------------------------------
Gradle 7.6
------------------------------------------------------------
Build time:   2022-11-25 13:35:10 UTC
Revision:     daece9dbc5b79370cc8e4fd6fe4b2cd400e150a8
Kotlin:       1.7.10
Groovy:       3.0.13
Ant:          Apache Ant(TM) version 1.10.11 compiled on July 10 2021
JVM:          18.0.1.1 (Oracle Corporation 18.0.1.1+2-6)
OS:           Mac OS X 13.1 aarch64

% mkdir gradle-app
% cd gradle-app
% gradle init --type java-library

Starting a Gradle Daemon (subsequent builds will be faster)
Select build script DSL:
  1: Groovy
  2: Kotlin
Enter selection (default: Groovy) [1..2] 1
Generate build using new APIs and behavior (some features may change in the next minor release)? (default: no) [yes, no] no
Select test framework:
  1: JUnit 4
  2: TestNG
  3: Spock
  4: JUnit Jupiter
Enter selection (default: JUnit Jupiter) [1..4] 4
Project name (default: gradle-app): gradle-app
Source package (default: gradle.app): gradle.app
> Task :init
Get more help with your project: https://docs.gradle.org/7.6/samples/sample_building_java_libraries.html
BUILD SUCCESSFUL in 1m 56s
2 actionable tasks: 2 executed

% tree -a
.
└── gradle-app
    ├── .gitattributes
    ├── .gitignore
    ├── .gradle
    │·· └── file-system.probe
    ├── gradle
    │·· └── wrapper
    │··     ├── gradle-wrapper.jar
    │··     └── gradle-wrapper.properties
    ├── gradlew
    ├── gradlew.bat
    ├── lib
    │·· ├── build.gradle
    │·· └── src
    │··     ├── main
    │··     │·· ├── java
    │··     │·· │·· └── gradle
    │··     │·· │··     └── app
    │··     │·· │··         └── Library.java
    │··     │·· └── resources
    │··     └── test
    │··         ├── java
    │··         │·· └── gradle
    │··         │··     └── app
    │··         │··         └── LibraryTest.java
    │··         └── resources
    └── settings.gradle

/*
 * This file was generated by the Gradle 'init' task.
 *
 * This generated file contains a sample Java library project to get you started.
 * For more details take a look at the 'Building Java & JVM projects' chapter in the Gradle
 * User Manual available at https://docs.gradle.org/7.6/userguide/building_java_projects.html
 */
plugins {
    // Apply the java-library plugin for API and implementation separation.
    id 'java-library'
}

repositories {
    // Use Maven Central for resolving dependencies.
    mavenCentral()
}

dependencies {
    // Use JUnit Jupiter for testing.
    testImplementation 'org.junit.jupiter:junit-jupiter:5.9.1'

    // This dependency is exported to consumers, that is to say found on their compile classpath.
    api 'org.apache.commons:commons-math3:3.6.1'

    // This dependency is used internally, and not exposed to consumers on their own compile classpath.
    implementation 'com.google.guava:guava:31.1-jre'
}

tasks.named('test') {
    // Use JUnit Platform for unit tests.
    useJUnitPlatform()
}

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

public class Library {
    public boolean someLibraryMethod(
) {
        return true;
    }
}

/*
 * This Java source file was generated by the Gradle 'init' task.
 */

package gradle.app;

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

class LibraryTest {
    @Test void someLibraryMethodReturnsTrue() {
        Library classUnderTest = new Library();
        assertTrue(classUnderTest.someLibraryMethod(), "someLibraryMethod should return 'true'");
    }
}

plugins {
    id 'java'
}

group 'org.example'
version '1.0-SNAPSHOT'

repositories {
    mavenCentral()
}

dependencies {
    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.8.1'
    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.8.1'
}

test {
    useJUnitPlatform()
}

rootProject.name = 'gradle-sample-intellij'

20:22:08: Executing 'build'...
Starting Gradle Daemon...
Gradle Daemon started in 718 ms
> Task :compileJava
> Task :processResources NO-SOURCE
> Task :classes
> Task :jar
> Task :assemble
> Task :compileTestJava NO-SOURCE
> Task :processTestResources NO-SOURCE
> Task :testClasses UP-TO-DATE
> Task :test NO-SOURCE
> Task :check UP-TO-DATE
> Task :build
BUILD SUCCESSFUL in 2s
2 actionable tasks: 2 executed
20:22:11: Execution finished 'build'.

% gradle --gui                                                                   
Unknown command-line option '--gui'.

task タスク名 {
  実行する処理
}

task greeting {
    doLast {
        println();
        println("Hello, World!");
    }
}

% gradle greeting
> Task :greeting
Hello, World!
BUILD SUCCESSFUL in 496ms
1 actionable task: 1 executed

gradle -q greeting

task actionOrder {
    doLast {
        println("This is last action.");
    }
    doFirst {
        println("This is first action.");
    }
}

% gradle actionOrder -q
This is first action.
This is last action.

task count {
    doLast {
        def total = 0;
        for (def i in 1..num.toInteger()) {
            total += i
        }
        printf("total: %s%n", total);
    }
}

% gradle -q count -Pnum=100
total: 5050

def items = ["apple", "orange", "banana"];

items.each {item ->
    task "$item" {
        doLast {
            println("This is task for $item.");
        }
    }
}

% gradle apple -q
This is task for apple.

plugins {
    id 'java'
}

apply plugin: 'java'

% gradle java
BUILD SUCCESSFUL in 459ms
2 actionable tasks: 2 up-to-date

task createJar(dependsOn: [compileJava, jar]) {
    doLast {
        println("compiled and jar is created.");
    }
}

% gradle createJar
> Task :createJar
compiled and jar is created.
BUILD SUCCESSFUL in 580ms
4 actionable tasks: 2 executed, 2 up-to-date

package org.example;

public class Main {
    public static void main(String[] args) {
        Main main = new Main();
        main.printGreeting("Kenji");
        main.printGreeting("Hiroko");
    }

    public String greeting(String name) {
        return String.format("I am %s.", name);
    }

    public void printGreeting(String name) {
        System.out.println(this.greeting(name));
    }
}

plugins {
    id 'java'
    id 'application'
}

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

% gradle -q run
I am Kenji.
I am Hiroko.

task executeMain(dependsOn:[jar, run]) {
    doLast {
        println("Start execution");
    }
}

% gradle executeMain
> Task :run
I am Kenji.
I am Hiroko.
> Task :executeMain
Start execution
BUILD SUCCESSFUL in 477ms
5 actionable tasks: 3 executed, 2 up-to-date

package org.example;

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

public class MainTest {
    @Test
    public void testMain() {
        String name = "Satoshi";
        Main main = new Main();
        assertNotNull(main);
        assertEquals("I am Satoshi.", main.greeting(name));
    }
}

% gradle test
BUILD SUCCESSFUL in 4s
4 actionable tasks: 4 executed