Added keyword "null" to java keywords

plugins/org.yakindu.sct.generator.java/src/org/yakindu/sct/generator/java/features/IJavaFeatureConstants.java

@@ -28,10 +28,10 @@ public interface IJavaFeatureConstants {
 	public static final String[] JAVA_KEYWORDS = { "abstract", "assert",
 		"boolean", "break", "byte", "case", "catch", "char", "class",
 		"const", "continue", "default", "do", "double", "else", "enum",
-		"extens", "final", "finally", "float", "for", "goto", "if",
+		"extends", "false", "final", "finally", "float", "for", "goto", "if",
 		"implements", "import", "instanceof", "int", "interface", "long",
-		"native", "new", "package", "private", "protected", "public",
+		"native", "new","null", "package", "private", "protected", "public",
 		"return", "short", "static", "strictfp", "super", "switch",
-		"synchronized", "this", "throw", "throws", "transient", "try",
+		"synchronized", "this", "throw", "throws", "transient", "true" , "try",
 		"void", "volatile", "while" };
 }