[WIP] Move to Java 9

build.gradle

@@ -1,9 +1,21 @@
 apply plugin: 'java'
 
-sourceCompatibility = 1.8
-targetCompatibility = 1.8
+sourceCompatibility = 1.9
+targetCompatibility = 1.9
 
 group = "org.jabref"
 version = "1.0.0"
 
+compileJava {
+    options.encoding = 'UTF-8'
+    options.sourcepath = files(sourceSets.main.java.srcDirs)
+    options.compilerArgs.addAll([
+            "--add-exports",
+            "javafx.base/com.sun.javafx.collections=customjfx"
+    ])
+    options.compilerArgs.addAll([
+            "--add-exports",
+            "javafx.graphics/com.sun.javafx.scene.input=customjfx"
+    ])
 
+}

src/main/java/org/jabref/gui/customjfx/support/module-info.java

@@ -0,0 +1,7 @@
+module customjfx {
+    requires java.desktop;
+    requires javafx.base;
+    requires javafx.graphics;
+
+    exports org.jabref.gui.customjfx.support;
+}