Port remaining usage of Kotlin in generator and samples to Java

.gitignore

@@ -14,6 +14,5 @@ includes_filtered.txt
 hs_err*
 
 sample_run
-.kotlin
 sample_output*
 sample*.jar

CONTRIBUTING.md

@@ -6,7 +6,7 @@ There are a few things I'm open to help with, but that I'd like to discuss first
 * Investigating whether we could offer a build of libvips in another module, to make integration easier
   * I'd definitely like X86 and ARM64 support for this
   * It should continue to work with cutting-edge versions of Java - not becoming a blocker to users upgrading their JVM
-* Refactoring the [generator](https://github.com/lopcode/vips-ffm/tree/main/generator/src/main/kotlin/vipsffm) classes
+* Refactoring the [generator](https://github.com/lopcode/vips-ffm/tree/main/generator/src/main/java/vipsffm) classes
   to make them a little less scrappy, and easier to reason about, without introducing too many "design patterns"
 
 Any change must be tested, either by using unit tests, or by improving the existing [samples](README.md#samples). The

README.md

@@ -23,7 +23,7 @@ repositories {
 }
 
 dependencies {
-    implementation("app.photofox.vips-ffm:vips-ffm-core:1.9.8")
+    implementation("app.photofox.vips-ffm:vips-ffm-core:1.9.9")
 }
 ```
 
@@ -43,35 +43,34 @@ generated from libvips `8.18.2` (but should be safe to use with different minor
 
 ### Thumbnail sample
 
-To get a feeling for the bindings, here's an indicative sample written in Kotlin (using the Java bindings) that:
+To get a feeling for the bindings, here's an indicative sample written in Java that:
 * Loads an original JPEG image from disk
 * Writes a copy of it to disk
 * Creates a 400px thumbnail from the original, and writes that to disk
 
-```kotlin
-import app.photofox.vipsffm.Vips
-import app.photofox.vipsffm.VImage
-import app.photofox.vipsffm.VipsOption
-import app.photofox.vipsffm.enums.VipsAccess
+```java
+import app.photofox.vipsffm.Vips;
+import app.photofox.vipsffm.VImage;
+import app.photofox.vipsffm.VipsOption;
 
 // ...
 
 // Use `Vips.run` to wrap your usage of the API, and get an arena with an appropriate lifetime to use
 // Usage of the API, arena, and resulting V-Objects must be done from the thread that called `Vips.run`
-Vips.run { arena ->
-    val thumbnail = VImage.thumbnail(
-      arena,
-      "sample/src/main/resources/sample_images/rabbit.jpg",
-      400,
-      VipsOption.Boolean("auto-rotate", true) // example of an option
-    )
-    val thumbnailWidth = thumbnail.width
-    val thumbnailHeight = thumbnail.height
-    logger.info("thumbnail image size: $thumbnailWidth x $thumbnailHeight")
-
-    val outputPath = workingDirectory.resolve("rabbit_thumbnail.jpg")
-    thumbnail.writeToFile(outputPath.absolutePathString())
-}
+Vips.run(arena -> {
+    var thumbnail = VImage.thumbnail(
+        arena,
+        "sample/src/main/resources/sample_images/rabbit.jpg",
+        400,
+        VipsOption.Boolean("auto-rotate", true) // example of an option
+    );
+    var thumbnailWidth = thumbnail.getWidth();
+    var thumbnailHeight = thumbnail.getHeight();
+    logger.info("thumbnail image size: {} x {}", thumbnailWidth, thumbnailHeight);
+
+    var outputPath = workingDirectory.resolve("rabbit_thumbnail.jpg");
+    thumbnail.writeToFile(outputPath.toAbsolutePath().toString());
+});
 
 // Optionally call at the end of your program, for memory leak detection, from any thread
 Vips.shutdown()
@@ -80,7 +79,7 @@ Vips.shutdown()
 ## Samples
 
 Samples are included that show various usages of these bindings. They include validations, and run on GitHub Actions as
-"end-to-end tests" during development. You can find them all listed [here](https://github.com/lopcode/vips-ffm/tree/main/sample/src/main/kotlin/vipsffm/sample).
+"end-to-end tests" during development. You can find them all listed [here](https://github.com/lopcode/vips-ffm/tree/main/sample/src/main/java/vipsffm/sample).
 
 To get set up to run samples (on macOS):
 * `brew install vips`

build.gradle.kts

@@ -1,3 +1,2 @@
 plugins {
-    kotlin("jvm") version "2.3.21" apply false
-}
+}

core/build.gradle.kts

@@ -51,11 +51,11 @@ tasks.withType<Javadoc> {
 testing {
     suites {
         val test by getting(JvmTestSuite::class) {
-            useKotlinTest("2.1.21")
+            useJUnitJupiter()
         }
 
         register<JvmTestSuite>("integrationTest") {
-            useKotlinTest("2.1.21")
+            useJUnitJupiter()
 
             dependencies {
                 implementation(project(":core"))

docs/index.html

@@ -86,42 +86,41 @@ <h2 id="usage-heading">Usage</h2>
 for. See details in <a href="#native-library-loading">native library loading</a>.</p>
 </blockquote>
 <h3 id="thumbnail-sample-heading">Thumbnail sample</h3>
-<p>To get a feeling for the bindings, here's an indicative sample written in Kotlin (using the Java bindings) that:</p>
+<p>To get a feeling for the bindings, here's an indicative sample written in Java that:</p>
 <ul>
 <li>Loads an original JPEG image from disk</li>
 <li>Writes a copy of it to disk</li>
 <li>Creates a 400px thumbnail from the original, and writes that to disk</li>
 </ul>
-<pre><code class="language-kotlin">import app.photofox.vipsffm.Vips
-import app.photofox.vipsffm.VImage
-import app.photofox.vipsffm.VipsOption
-import app.photofox.vipsffm.enums.VipsAccess
+<pre><code class="language-java">import app.photofox.vipsffm.Vips;
+import app.photofox.vipsffm.VImage;
+import app.photofox.vipsffm.VipsOption;
 
 // ...
 
 // Use `Vips.run` to wrap your usage of the API, and get an arena with an appropriate lifetime to use
 // Usage of the API, arena, and resulting V-Objects must be done from the thread that called `Vips.run`
-Vips.run { arena -&gt;
-    val thumbnail = VImage.thumbnail(
-      arena,
-      &quot;sample/src/main/resources/sample_images/rabbit.jpg&quot;,
-      400,
-      VipsOption.Boolean(&quot;auto-rotate&quot;, true) // example of an option
-    )
-    val thumbnailWidth = thumbnail.width
-    val thumbnailHeight = thumbnail.height
-    logger.info(&quot;thumbnail image size: $thumbnailWidth x $thumbnailHeight&quot;)
+Vips.run(arena -&gt; {
+    var thumbnail = VImage.thumbnail(
+        arena,
+        &quot;sample/src/main/resources/sample_images/rabbit.jpg&quot;,
+        400,
+        VipsOption.Boolean(&quot;auto-rotate&quot;, true) // example of an option
+    );
+    var thumbnailWidth = thumbnail.getWidth();
+    var thumbnailHeight = thumbnail.getHeight();
+    logger.info(&quot;thumbnail image size: {} x {}&quot;, thumbnailWidth, thumbnailHeight);
 
-    val outputPath = workingDirectory.resolve(&quot;rabbit_thumbnail.jpg&quot;)
-    thumbnail.writeToFile(outputPath.absolutePathString())
-}
+    var outputPath = workingDirectory.resolve(&quot;rabbit_thumbnail.jpg&quot;);
+    thumbnail.writeToFile(outputPath.toAbsolutePath().toString());
+});
 
 // Optionally call at the end of your program, for memory leak detection, from any thread
 Vips.shutdown()
 </code></pre>
 <h2 id="samples-heading">Samples</h2>
 <p>Samples are included that show various usages of these bindings. They include validations, and run on GitHub Actions as
-&quot;end-to-end tests&quot; during development. You can find them all listed <a href="https://github.com/lopcode/vips-ffm/tree/main/sample/src/main/kotlin/vipsffm/sample">here</a>.</p>
+&quot;end-to-end tests&quot; during development. You can find them all listed <a href="https://github.com/lopcode/vips-ffm/tree/main/sample/src/main/java/vipsffm/sample">here</a>.</p>
 <p>To get set up to run samples (on macOS):</p>
 <ul>
 <li><code>brew install vips</code></li>

generator/build.gradle.kts

@@ -4,7 +4,7 @@ import org.gradle.api.tasks.testing.logging.TestExceptionFormat
 import org.gradle.api.tasks.testing.logging.TestLogEvent
 
 plugins {
-    kotlin("jvm")
+    java
     id("com.gradleup.shadow") version "9.4.1"
     application
 }
@@ -17,7 +17,6 @@ dependencies {
     implementation(project(":core"))
     implementation(platform("org.slf4j:slf4j-bom:2.0.17"))
     implementation("com.fasterxml.jackson.dataformat:jackson-dataformat-xml:2.21.3")
-    implementation("com.fasterxml.jackson.module:jackson-module-kotlin:2.21.3")
     implementation("org.apache.commons:commons-text:1.15.0")
     implementation("com.palantir.javapoet:javapoet:0.15.0")
     implementation("org.slf4j:slf4j-api")
@@ -26,14 +25,15 @@ dependencies {
 
 java {
     toolchain {
-        languageVersion.set(JavaLanguageVersion.of(23))
+        // the generator uses the Class-File API, which was finalised in JDK 24
+        languageVersion.set(JavaLanguageVersion.of(24))
     }
 }
 
 testing {
     suites {
         val test by getting(JvmTestSuite::class) {
-            useKotlinTest("2.1.21")
+            useJUnitJupiter()
         }
     }
 }
@@ -53,9 +53,8 @@ tasks.withType<Jar>().configureEach {
 }
 
 application {
-    mainClass = "vipsffm.MainKt"
+    mainClass = "vipsffm.Main"
     applicationDefaultJvmArgs = listOf(
-        "--enable-preview",
         "--enable-native-access=ALL-UNNAMED"
     )
     tasks.run.get().workingDir = rootProject.projectDir