use utf-8 as resource encoding

build.gradle

@@ -46,7 +46,6 @@ subprojects {
 	// java compatibility version
 	sourceCompatibility = 11
 	
-
 	configurations {
 		tests
 	}
@@ -70,6 +69,20 @@ subprojects {
 	}
 }
 
+allprojects {
+ 	compileJava.options.encoding = 'UTF-8'
+ 	
+ 	eclipseJdt.doLast {
+	    File f = file('.settings/org.eclipse.core.resources.prefs')
+	    f.write('eclipse.preferences.version=1\n')
+	    f.append('encoding/<project>=UTF-8')
+	}
+	
+	cleanEclipse.doLast {
+		file('.settings/org.eclipse.core.resources.prefs').delete()
+	}
+}
+
 task wrapper(type: Wrapper) {
     gradleVersion = '4.10.2'
 }

eclipse/org.eclipse.core.resources.prefs

@@ -0,0 +1,2 @@
+eclipse.preferences.version=1
+encoding/<project>=UTF-8