X-Git-Url: http://nitlanguage.org

diff --git a/lib/java/java.nit b/lib/java/java.nit
index cf13a15..2020e30 100644
--- a/lib/java/java.nit
+++ b/lib/java/java.nit
@@ -27,8 +27,8 @@
 # most of JNI functions. You can use it to further customize the behavior
 # of your code.
 module java is
-	c_compiler_option("-I $(JAVA_HOME)/include/")
-	c_linker_option("-L $(JNI_LIB_PATH) -ljvm")
+	cflags "-I $(JAVA_HOME)/include/ -I $(JAVA_HOME)/include/linux/"
+	ldflags "-L $(JNI_LIB_PATH) -ljvm"
 	new_annotation extra_java_files
 end
 
@@ -98,8 +98,6 @@ end
 extern class JavaString in "Java" `{ java.lang.String `}
 	super JavaObject
 
-	redef type SELF: JavaString
-
 	# Get the string from Java and copy it to Nit memory
 	fun to_cstring: NativeString import sys, Sys.jni_env `{
 		Sys sys = JavaString_sys(recv);
@@ -140,7 +138,6 @@ redef class Text
 end
 
 redef extern class JavaObject
-	type SELF: JavaObject
 
 	# Returns a global reference to the Java object behind this reference
 	#
@@ -178,4 +175,26 @@ redef extern class JavaObject
 	private fun pop_from_local_frame_with_env(jni_env: JniEnv): SELF `{
 		return (*jni_env)->PopLocalFrame(jni_env, recv);
 	`}
+
+	# Is `self` null in Java?
+	#
+	# Since Java type system doesn't have the same `nullable` concept as Nit's,
+	# the two systems are not directly compatible. Any Nit instances of
+	# `JavaObject` may hold a Java null.
+	#
+	# To benefit from the safer type system of Nit, it is recommended to check
+	# the return of all extern methods implemented in Java to ensure the value
+	# is not a Java null. In case it is, you should replace it by a normal Nit
+	# `null`.
+	fun is_java_null: Bool in "Java" `{ return recv == null; `}
+
+	# `JavaString` representation of `self` using Java's `toString`
+	fun to_java_string: JavaString in "Java" `{ return recv.toString(); `}
+
+	# Use Java's `toString` for any `JavaObject`
+	redef fun to_s
+	do
+		if is_java_null then return super
+		return to_java_string.to_s
+	end
 end