update Java example project to demonstrate feature variants (#217)

- add new subproject to the java-example project, to demonstrate how to enable feature-variant source sets
- test the java-example project

examples/java-example/dokkatoo/README.md

@@ -3,6 +3,13 @@
 This project demonstrates how Dokkatoo can be applied to a pure Java project
 to generate documentation.
 
+This project has multiple modules.
+
+* [my-java-application](./my-java-application) is a Java Application
+* [my-java-application](./my-java-features) is a Java Library, demonstrating
+  [feature variants](https://docs.gradle.org/current/userguide/feature_variants.html).
+* [my-java-application](./my-java-library) is a Java Library
+
 ### Demonstration
 
 To generate HTML documentation, run
@@ -11,6 +18,8 @@ To generate HTML documentation, run
 gradle :dokkatooGeneratePublicationHtml
 ```
 
+The HTML documentation will be generated into [build/dokka/html](./build/dokka/html/).
+
 ### Implementation details
 
 Note that the `org.jetbrains.dokka:kotlin-as-java-plugin` Dokka Plugin

examples/java-example/dokkatoo/build.gradle.kts

@@ -4,6 +4,7 @@ plugins {
 
 dependencies {
   dokkatoo(project(":my-java-application"))
+  dokkatoo(project(":my-java-features"))
   dokkatoo(project(":my-java-library"))
 
   dokkatooPluginHtml("org.jetbrains.dokka:templating-plugin")

examples/java-example/dokkatoo/buildSrc/src/main/kotlin/dokka-convention.gradle.kts

@@ -17,8 +17,5 @@ dokkatoo {
 }
 
 dependencies {
-  dokkatooPluginHtml("org.jetbrains.dokka:kotlin-as-java-plugin")
-  dokkatooPluginJavadoc("org.jetbrains.dokka:kotlin-as-java-plugin")
-  dokkatooPluginJekyll("org.jetbrains.dokka:kotlin-as-java-plugin")
-  dokkatooPluginGfm("org.jetbrains.dokka:kotlin-as-java-plugin")
+  dokkatooPlugin("org.jetbrains.dokka:kotlin-as-java-plugin")
 }

examples/java-example/dokkatoo/buildSrc/src/main/kotlin/my-java-mongodb-convention.gradle.kts

@@ -0,0 +1,15 @@
+plugins {
+  `java-library`
+}
+
+val mongodbSourceSet = sourceSets.create("mongodbSupport") {
+  java {
+    srcDir("src/mongodb/java")
+  }
+}
+
+java {
+  registerFeature("mongodbSupport") {
+    usingSourceSet(mongodbSourceSet)
+  }
+}

examples/java-example/dokkatoo/my-java-features/Module.md

@@ -0,0 +1,11 @@
+# Module My Java Features
+
+This is the API reference for My Java Features.
+
+# Package demo.feature
+
+This package contains common feature classes.
+
+# Package demo.mongodb
+
+This package contains MongoDB feature classes.

examples/java-example/dokkatoo/my-java-features/build.gradle.kts

@@ -0,0 +1,20 @@
+plugins {
+  `my-java-mongodb-convention`
+  `dokka-convention`
+}
+
+dokkatoo {
+  dokkatooSourceSets.configureEach {
+    includes.from("Module.md")
+  }
+
+  dokkatooSourceSets.javaMain {
+    displayName = "Java"
+  }
+
+  // non-main source sets are suppressed by default
+  dokkatooSourceSets.javaMongodbSupport {
+    suppress = false
+    displayName = "MongoDB"
+  }
+}

examples/java-example/dokkatoo/my-java-features/src/main/java/demo/feature/MyJavaFeatureUtil.java

@@ -0,0 +1,4 @@
+package demo.feature;
+
+public class MyJavaFeatureUtil {
+}

examples/java-example/dokkatoo/my-java-features/src/mongodbSupport/java/demo/mongodb/MyMongoDbUtil.java

@@ -0,0 +1,4 @@
+package demo.mongodb;
+
+public class MyMongoDbUtil {
+}

examples/java-example/dokkatoo/settings.gradle.kts

@@ -1,4 +1,4 @@
-rootProject.name = "dokkatoo-multimodule-example"
+rootProject.name = "dokkatoo-java-example"
 
 pluginManagement {
   repositories {
@@ -43,4 +43,5 @@ dependencyResolutionManagement {
 }
 
 include(":my-java-application")
+include(":my-java-features")
 include(":my-java-library")