Fix migration of serial library to Gradle

java/libraries/serial/.gitignore

@@ -1 +1,2 @@
 bin
+build

java/libraries/serial/build.gradle.kts

@@ -1 +1,34 @@
-ant.importBuild("build.xml")
+plugins {
+    java
+}
+
+java {
+    toolchain {
+        languageVersion.set(JavaLanguageVersion.of(17))
+    }
+}
+
+val coreJar = file("../../../core/library/core.jar")
+
+dependencies {
+
+    implementation(project(":core"))
+    implementation(files("library/jssc.jar"))
+}
+
+tasks.register("checkCore") {
+    doFirst {
+
+        if (!coreJar.exists()) {
+            throw GradleException("Missing core.jar at $coreJar. Please build the core module first.")
+        }
+    }
+}
+
+tasks.register<Jar>("serialJar") {
+    dependsOn("checkCore", "classes")
+    archiveBaseName.set("serial")
+    destinationDirectory.set(file("library"))
+    from(sourceSets.main.get().output)
+}
+

java/settings.gradle.kts

@@ -0,0 +1,16 @@
+plugins {
+    id("org.gradle.toolchains.foojay-resolver-convention") version "0.10.0"
+}
+
+rootProject.name = "processing"
+
+include(":app")
+include(":core")
+include(":java:preprocessor")
+
+include(":java:libraries:dxf")
+include(":java:libraries:io")
+include(":java:libraries:net")
+include(":java:libraries:pdf")
+include(":java:libraries:serial")
+include(":java:libraries:svg")