refs #227 refs #228: Includes pom.xml in Jars, fixes gradle consumer (#229)

Add manual configuration for including the pom.xml and pom.properties
file in the Jar META-INF folder.

Gradle projects were failing to use the library unless they explicitly
defined the AWS BOM. This was not the case with Maven users. The cause
was the BOM being an `implementation` and not an `api` dependency.

Author: JaidenAshmore

build.gradle.kts

@@ -31,9 +31,10 @@ subprojects {
     dependencies {
         // AWS
         implementation(platform("software.amazon.awssdk:bom:2.13.58"))
+        api(platform("software.amazon.awssdk:bom:2.13.58"))
 
         // Spring Boot
-        implementation(platform("org.springframework.boot:spring-boot-dependencies:2.3.1.RELEASE"))
+        api(platform("org.springframework.boot:spring-boot-dependencies:2.3.1.RELEASE"))
 
         // Lombok
         compileOnly("org.projectlombok:lombok:1.18.12")

buildSrc/src/main/kotlin/com/jashmore/gradle/ReleasePlugin.kt

@@ -10,13 +10,19 @@ import org.gradle.api.plugins.JavaPluginExtension
 import org.gradle.api.publish.PublishingExtension
 import org.gradle.api.publish.maven.MavenPublication
 import org.gradle.api.publish.maven.plugins.MavenPublishPlugin
+import org.gradle.api.tasks.bundling.Jar
 import org.gradle.kotlin.dsl.configure
 import org.gradle.kotlin.dsl.create
 import org.gradle.kotlin.dsl.get
+import org.gradle.kotlin.dsl.withType
 import org.gradle.plugins.signing.SigningExtension
 import org.gradle.plugins.signing.SigningPlugin
 import java.io.File
 import java.net.URI
+import java.text.DateFormat
+import java.text.SimpleDateFormat
+import java.time.OffsetDateTime
+import java.time.format.DateTimeFormatter
 
 open class ReleasePluginExtension {
     /**
@@ -68,6 +74,9 @@ open class ReleasePlugin : Plugin<Project> {
             val deploymentTag = if (isSnapshotVersion(projectVersion)) "HEAD" else "v$projectVersion"
 
             project.subprojects.forEach { subProject ->
+                val groupId = subProject.group as String
+                val artifactId = subProject.name.replace(":", "")
+
                 val isExamplesModule = subProject.projectDir.path.contains("examples")
                 val moduleCompilesJava = subProject.plugins.hasPlugin("java")
                 if (!isExamplesModule && moduleCompilesJava) {
@@ -82,9 +91,9 @@ open class ReleasePlugin : Plugin<Project> {
 
                     subProject.configure<PublishingExtension> {
                         publications {
-                            create<MavenPublication>("mavenJava") {
-                                groupId = subProject.group as String
-                                artifactId = subProject.name.replace(":", "")
+                             create<MavenPublication>("mavenJava") {
+                                this.groupId = groupId
+                                this.artifactId = artifactId
                                 version = projectVersion
 
                                 from(subProject.components["java"])
@@ -142,6 +151,29 @@ open class ReleasePlugin : Plugin<Project> {
                         }
                     }
 
+                    // Populate the Jars with a pom.xml and pom.properties file
+                    subProject.tasks.withType<Jar> {
+                        into("META-INF/maven/$groupId/$artifactId") {
+                            from(subProject.tasks.getByName("generatePomFileForMavenJavaPublication"))
+
+                            rename("pom-default.xml", "pom.xml")
+                        }
+
+                        into("META-INF/maven/$groupId/$artifactId") {
+                            val propertiesFile = File.createTempFile("pom", ".properties")
+                            propertiesFile.writeText("""
+                                # Generated by Gradle
+                                # ${DateTimeFormatter.ISO_DATE_TIME.format(OffsetDateTime.now())}
+                                groupId=${groupId}
+                                artifactId=${artifactId}
+                                version=${projectVersion}
+                            """.trimIndent())
+                            from(propertiesFile)
+
+                            rename(propertiesFile.name, "pom.properties")
+                        }
+                    }
+
                     subProject.configure<SigningExtension> {
                         // We only want to sign if we are actually publishing to Maven Central
                         setRequired({ project.gradle.taskGraph.hasTask("publishMavenJavaPublicationToMavenRepository") })