Merge pull request #114 from gradle/tt/add-template-for-java-library

Setup project generation for sample declarative java library and java application projects

unified-prototype/gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions-snapshots/gradle-8.10-20240719001820+0000-bin.zip
+distributionUrl=https\://services.gradle.org/distributions-snapshots/gradle-8.11-20240812191308+0000-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME

unified-prototype/unified-plugin/plugin-common/build.gradle.kts

@@ -1,16 +1,44 @@
 plugins {
     `kotlin-dsl`
     id("build-logic.publishing")
+    groovy // For spock testing
 }
 
 description = "Common APIs and implementation classes shared by the ecosystem specific declarative prototypes"
 
 dependencies {
     implementation(libs.android.agp.application)
 
+    implementation("commons-io:commons-io:2.8.0")
     implementation(gradleApi())
 }
 
+testing {
+    suites {
+        @Suppress("UnstableApiUsage")
+        val test by getting(JvmTestSuite::class) {
+            useSpock("2.2-groovy-3.0")
+
+            dependencies {
+                implementation("commons-io:commons-io:2.8.0")
+            }
+        }
+
+        @Suppress("UnstableApiUsage")
+        val integTest by registering(JvmTestSuite::class) {
+            useSpock("2.2-groovy-3.0")
+
+            dependencies {
+                implementation("commons-io:commons-io:2.8.0")
+                implementation(project(":plugin-jvm"))
+                implementation(project())
+            }
+        }
+
+        tasks.getByPath("check").dependsOn(integTest)
+    }
+}
+
 gradlePlugin {
     plugins {
         create("common") {

unified-prototype/unified-plugin/plugin-common/output/build.gradle.dcl

@@ -0,0 +1,8 @@
+javaLibrary {
+    javaVersion = 21
+
+    dependencies {
+        implementation(project(":java-util"))
+        implementation("com.google.guava:guava:32.1.3-jre")
+    }
+}

unified-prototype/unified-plugin/plugin-common/output/src/main/java/com/example/lib/Library.java

@@ -0,0 +1,13 @@
+package com.example.lib;
+
+import com.google.common.collect.ImmutableList;
+
+public class Library {
+    public Iterable<String> getMessages() {
+        // Verify that Guava is available
+        ImmutableList.Builder<String> builder = ImmutableList.builder();
+        builder.add("Hello from Java " + System.getProperty("java.version"));
+
+        return builder.build();
+    }
+}

unified-prototype/unified-plugin/plugin-common/src/integTest/groovy/org/gradle/util/ResourceLoaderIntegrationTest.groovy

@@ -0,0 +1,29 @@
+package org.gradle.util
+
+import org.apache.commons.io.FileUtils
+import spock.lang.Specification
+
+class ResourceLoaderIntegrationTest extends Specification {
+    File outputDir
+
+    def setup() {
+        outputDir = new File("build/tmp/integTest/output").tap { deleteDir() }
+    }
+
+    def "can load resource from jar file"() {
+        given:
+        ResourceLoader resourceLoader = new ResourceLoader()
+
+        when:
+        resourceLoader.extractResourcesFromJar("templates/java-library", outputDir)
+
+        then:
+        assertOutputIs(['build.gradle.dcl', 'src/main/java/com/example/lib/Library.java'])
+    }
+
+    private void assertOutputIs(List<String> expectedRelativePaths) {
+        def actualPaths = FileUtils.listFiles(outputDir, null, true)*.path
+        def expectedPaths = expectedRelativePaths.collect { "${outputDir.toPath()}/$it".toString() }
+        assert actualPaths == expectedPaths
+    }
+}

unified-prototype/unified-plugin/plugin-common/src/main/java/org/gradle/api/experimental/buildinit/StaticProjectGenerator.java

@@ -0,0 +1,31 @@
+package org.gradle.api.experimental.buildinit;
+
+import org.gradle.api.file.Directory;
+import org.gradle.buildinit.projectspecs.InitProjectConfig;
+import org.gradle.buildinit.projectspecs.InitProjectGenerator;
+import org.gradle.util.ResourceLoader;
+
+/**
+ * An {@link InitProjectGenerator} that generates a project from a static template packaged
+ * as resources files in the {@link #TEMPLATES_ROOT} directory.
+ */
+@SuppressWarnings("UnstableApiUsage")
+public final class StaticProjectGenerator implements InitProjectGenerator {
+    private static final String TEMPLATES_ROOT = "templates";
+
+    @Override
+    public void generate(InitProjectConfig config, Directory projectDir) {
+        if (!(config.getProjectSpec() instanceof StaticProjectSpec projectSpec)) {
+            throw new IllegalArgumentException("Unknown project type: " + config.getProjectSpec().getDisplayName() + " (" + config.getProjectSpec().getClass().getName() + ")");
+        }
+
+        String templatePath = TEMPLATES_ROOT + "/" + projectSpec.getTemplatePath();
+        ResourceLoader resourceLoader = new ResourceLoader();
+
+        try {
+            resourceLoader.extractResourcesFromJar(templatePath, projectDir.getAsFile());
+        } catch (Exception e) {
+            throw new RuntimeException("Error extracting resources for: '" + projectSpec.getDisplayName() + "' from: '" + templatePath + "'!", e);
+        }
+    }
+}

unified-prototype/unified-plugin/plugin-common/src/main/java/org/gradle/api/experimental/buildinit/StaticProjectSpec.java

@@ -0,0 +1,36 @@
+package org.gradle.api.experimental.buildinit;
+
+import org.gradle.buildinit.projectspecs.InitProjectParameter;
+import org.gradle.buildinit.projectspecs.InitProjectSpec;
+
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * An {@link InitProjectSpec} that represents a project that can be generated from a static template
+ * using the {@link StaticProjectGenerator}
+ */
+@SuppressWarnings("UnstableApiUsage")
+public final class StaticProjectSpec implements InitProjectSpec {
+    private final String templatePath;
+    private final String displayName;
+
+    public StaticProjectSpec(String templatePath, String displayName) {
+        this.templatePath = templatePath;
+        this.displayName = displayName;
+    }
+
+    @Override
+    public String getDisplayName() {
+        return displayName;
+    }
+
+    @Override
+    public List<InitProjectParameter<?>> getParameters() {
+        return Collections.emptyList();
+    }
+
+    public String getTemplatePath() {
+        return templatePath;
+    }
+}

unified-prototype/unified-plugin/plugin-common/src/main/java/org/gradle/util/ResourceLoader.java

@@ -0,0 +1,61 @@
+package org.gradle.util;
+
+import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.IOUtils;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.JarURLConnection;
+import java.net.URL;
+import java.util.Iterator;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+
+/**
+ * Static util class containing methods for loading resources from the classpath.
+ */
+public final class ResourceLoader {
+    /**
+     * Recursively extracts the contents of a directory in a jar file on the classpath to a specified directory.
+     *
+     * @param relativePath path to the source directory within the jar file
+     * @param destDir target directory to extract the contents to
+     * @throws IOException if an I/O error occurs
+     */
+    public void extractResourcesFromJar(String relativePath, File destDir) throws IOException {
+        URL jarDirURL = ResourceLoader.class.getClassLoader().getResource(relativePath);
+        if (jarDirURL == null) {
+            throw new IllegalArgumentException("Directory: '" + relativePath + "' not found on classpath.");
+        }
+        JarFile jarFile = ((JarURLConnection) jarDirURL.openConnection()).getJarFile();
+        System.out.println("Using URL: " + jarDirURL);
+
+        Iterator<JarEntry> iterator = jarFile.entries().asIterator();
+        while (iterator.hasNext()) {
+            JarEntry entry = iterator.next();
+            String entryName = entry.getName();
+
+            if (entryName.startsWith(relativePath)) {
+                String entrySuffix = entryName.substring(relativePath.length());
+                System.out.println("Entry: " + entry + " name: " + entryName + " suffix: " + entrySuffix);
+                File destFile = new File(destDir, entrySuffix);
+                System.out.println("Dest file: " + destFile);
+
+                if (entry.isDirectory()) {
+                    System.out.println("Is directory");
+                    FileUtils.forceMkdir(destFile);
+                    System.out.println("Created directory");
+                } else {
+                    System.out.println("Is file");
+                    try (InputStream is = jarFile.getInputStream(entry);
+                         FileOutputStream fos = new FileOutputStream(destFile)) {
+                        IOUtils.copy(is, fos);
+                    }
+                    System.out.println("Copied file");
+                }
+            }
+        }
+    }
+}

unified-prototype/unified-plugin/plugin-common/src/test/groovy/org/gradle/util/ResourceLoaderTest.groovy

@@ -0,0 +1,20 @@
+package org.gradle.util
+
+import org.apache.commons.io.FileUtils
+
+import spock.lang.Specification
+
+class ResourceLoaderTest extends Specification {
+    def "can load resource from jar file"() {
+        given:
+        File output = new File("output").tap { mkdirs() }
+        ResourceLoader resourceLoader = new ResourceLoader(this.getClass().getClassLoader())
+
+        when:
+        File templatesDir = resourceLoader.getResource("templates/java-library")
+        FileUtils.copyDirectory(templatesDir, output)
+
+        then:
+        FileUtils.listFiles(output, null, true)*.path == ['output/build.gradle.dcl', 'output/src/main/java/com/example/lib/Library.java']
+    }
+}

unified-prototype/unified-plugin/plugin-common/src/test/resources/templates/java-library/build.gradle.dcl

@@ -0,0 +1,8 @@
+javaLibrary {
+    javaVersion = 21
+
+    dependencies {
+        implementation(project(":java-util"))
+        implementation("com.google.guava:guava:32.1.3-jre")
+    }
+}

unified-prototype/unified-plugin/plugin-common/src/test/resources/templates/java-library/src/main/java/com/example/lib/Library.java

@@ -0,0 +1,13 @@
+package com.example.lib;
+
+import com.google.common.collect.ImmutableList;
+
+public class Library {
+    public Iterable<String> getMessages() {
+        // Verify that Guava is available
+        ImmutableList.Builder<String> builder = ImmutableList.builder();
+        builder.add("Hello from Java " + System.getProperty("java.version"));
+
+        return builder.build();
+    }
+}

unified-prototype/unified-plugin/plugin-jvm/build.gradle.kts

@@ -7,7 +7,9 @@ description = "Implements the declarative JVM DSL prototype"
 
 dependencies {
     implementation(project(":plugin-common"))
+    implementation("commons-io:commons-io:2.8.0")
     implementation("org.gradle.toolchains:foojay-resolver:0.8.0")
+    implementation(gradleApi())
 }
 
 gradlePlugin {

unified-prototype/unified-plugin/plugin-jvm/src/main/java/org/gradle/api/experimental/buildinit/JVMProjectSource.java

@@ -0,0 +1,27 @@
+package org.gradle.api.experimental.buildinit;
+
+import java.util.Arrays;
+import java.util.List;
+
+import org.gradle.buildinit.projectspecs.InitProjectGenerator;
+import org.gradle.buildinit.projectspecs.InitProjectSpec;
+import org.gradle.buildinit.projectspecs.InitProjectSource;
+
+/**
+ * A {@link InitProjectSource} of project specifications for JVM projects.
+ */
+@SuppressWarnings("UnstableApiUsage")
+public final class JVMProjectSource implements InitProjectSource {
+    @Override
+    public List<InitProjectSpec> getProjectSpecs() {
+        return Arrays.asList(
+            new StaticProjectSpec("java-library", "Declarative Java Library Project"),
+            new StaticProjectSpec("java-application", "Declarative Java Application Project")
+        );
+    }
+
+    @Override
+    public InitProjectGenerator getProjectGenerator() {
+        return new StaticProjectGenerator();
+    }
+}

unified-prototype/unified-plugin/plugin-jvm/src/main/java/org/gradle/api/experimental/buildinit/package-info.java

@@ -0,0 +1,2 @@
+@org.gradle.api.NonNullApi
+package org.gradle.api.experimental.buildinit;

unified-prototype/unified-plugin/plugin-jvm/src/main/resources/META-INF/services/org.gradle.buildinit.projectspecs.InitProjectSource

@@ -0,0 +1 @@
+org.gradle.api.experimental.buildinit.JVMProjectSource

unified-prototype/unified-plugin/plugin-jvm/src/main/resources/templates/java-application/build.gradle.dcl

@@ -0,0 +1,21 @@
+package templates.`java-application`
+
+javaApplication {
+    // compile for 17
+    javaVersion = 17
+    mainClass = "com.example.App"
+
+    dependencies {
+        implementation(project(":java-util"))
+        implementation("com.google.guava:guava:32.1.3-jre")
+    }
+
+    testing {
+        // test on 21
+        testJavaVersion = 21
+
+        dependencies {
+            implementation("org.junit.jupiter:junit-jupiter:5.10.2")
+        }
+    }
+}

unified-prototype/unified-plugin/plugin-jvm/src/main/resources/templates/java-application/src/main/java/com/example/App.java

@@ -0,0 +1,19 @@
+package com.example;
+
+import com.example.utils.Utils;
+import com.google.common.collect.ImmutableList;
+
+public class App {
+    public static void main(String[] args) {
+        // Verify that Guava is available
+        ImmutableList.Builder<String> builder = ImmutableList.builder();
+        builder.add("Hello from Java " + System.getProperty("java.version"));
+
+        // Verify that the Java library is available
+        Utils utils = new Utils();
+        builder.add(utils.getWelcome());
+
+        ImmutableList<String> messages = builder.build();
+        messages.forEach(System.out::println);
+    }
+}

unified-prototype/unified-plugin/plugin-jvm/src/main/resources/templates/java-application/src/test/java/com/example/AppTest.java

@@ -0,0 +1,10 @@
+package com.example;
+
+import org.junit.jupiter.api.Test;
+
+public class AppTest {
+    @Test
+    void appHasATest() {
+        assert true;
+    }
+}

unified-prototype/unified-plugin/plugin-jvm/src/main/resources/templates/java-library/build.gradle.dcl

@@ -0,0 +1,8 @@
+javaLibrary {
+    javaVersion = 21
+
+    dependencies {
+        implementation(project(":java-util"))
+        implementation("com.google.guava:guava:32.1.3-jre")
+    }
+}