make build java 1.8 compatible

build.gradle.kts

@@ -2,8 +2,6 @@ import org.jetbrains.kotlin.gradle.dsl.KotlinJvmCompile
 
 plugins {
     kotlin("jvm") version "1.4.30"
-    id("application")
-    id("org.openjfx.javafxplugin") version "0.0.9"
     idea
 }
 
@@ -22,35 +20,34 @@ dependencies {
 
     implementation("se.llbit:chunky-core:2.4.0-SNAPSHOT")
 
-    implementation(platform("com.fasterxml.jackson:jackson-bom:2.12.+"))
-    implementation("com.fasterxml.jackson.core:jackson-databind")
-    implementation("com.fasterxml.jackson.module:jackson-module-kotlin")
-    implementation("com.fasterxml.jackson.datatype:jackson-datatype-jsr310")
-
     implementation("no.tornado:tornadofx:1.7.20")
 }
 
-javafx {
-    version = "15.0.1"
-    modules = listOf("javafx.controls", "javafx.fxml")
-}
-application {
-    mainClass.set("de.groovybyte.chunky.magickexportplugin.MagickExportPluginKt")
-}
-tasks.withType<Jar> {
-    manifest {
-        attributes["Main-Class"] = application.mainClass.get()
+tasks {
+    withType<JavaCompile> {
+        sourceCompatibility = "1.8"
+        targetCompatibility = "1.8"
     }
-    configurations["compileClasspath"].forEach { file: File ->
-        from(zipTree(file.absoluteFile))
+    withType<Jar> {
+        archiveFileName.set("${archiveBaseName.get()}.${archiveExtension.get()}")
+        configurations["compileClasspath"].apply {
+            files { dep ->
+                when {
+                    dep.name.startsWith("chunky") -> false
+                    else -> true
+                }
+            }.forEach { file ->
+                from(zipTree(file.absoluteFile))
+            }
+        }
     }
-}
 
-tasks.withType<KotlinJvmCompile> {
-    kotlinOptions {
-        jvmTarget = "1.8"
-        languageVersion = "1.4"
-        useIR = true
+    withType<KotlinJvmCompile> {
+        kotlinOptions {
+            jvmTarget = "1.8"
+            languageVersion = "1.4"
+            useIR = true
+        }
     }
 }