diff --git a/src/ffi/java/workspace.rs b/src/ffi/java/workspace.rs
index 3599f69..2a5bce5 100644
--- a/src/ffi/java/workspace.rs
+++ b/src/ffi/java/workspace.rs
@@ -54,7 +54,114 @@ pub extern "system" fn Java_mp_code_Workspace_create_1buffer<'local>(
 	self_ptr: jlong,
 	input: JString<'local>
 ) {
-	let ws: Box<Workspace> = unsafe { Box::from_raw(self_ptr as *mut Workspace) };
+	let ws = unsafe { Box::leak(Box::from_raw(self_ptr as *mut Workspace)) };
 	let path = unsafe { env.get_string_unchecked(&input).expect("Couldn't get java string!") };
 	RT.block_on(ws.create(path.to_str().expect("Not UTF-8"))).jexcept(&mut env);
 }
+
+/*
+ * Class:     mp_code_Workspace
+ * Method:    get_file_tree
+ * Signature: (J)V
+ */
+#[no_mangle]
+pub extern "system" fn Java_mp_code_Workspace_get_1file_1tree<'local>(
+	mut env: JNIEnv,
+	_class: JClass<'local>,
+	self_ptr: jlong,
+) {
+	let workspace  = unsafe { Box::leak(Box::from_raw(self_ptr as *mut Workspace)) };
+    let file_tree = workspace.filetree();
+    todo!() // how to return Vec<String> ? []String ?
+}
+
+/*
+ * Class:     mp_code_Workspace
+ * Method:    attach_to_buffer
+ * Signature: (J)J
+ */
+#[no_mangle]
+pub extern "system" fn Java_mp_code_Workspace_attach_1to_1buffer<'local>(
+	mut env: JNIEnv,
+	_class: JClass<'local>,
+	_self_ptr: jlong,
+) -> jlong {
+    todo!()
+}
+
+/*
+ * Class:     mp_code_Workspace
+ * Method:    fetch_buffers
+ * Signature: (J)V
+ */
+#[no_mangle]
+pub extern "system" fn Java_mp_code_Workspace_fetch_1buffers<'local>(
+	mut env: JNIEnv,
+	_class: JClass<'local>,
+	self_ptr: jlong,
+) {
+	let workspace  = unsafe { Box::leak(Box::from_raw(self_ptr as *mut Workspace)) };
+    RT.block_on(workspace.fetch_buffers()).jexcept(&mut env);
+}
+
+/*
+ * Class:     mp_code_Workspace
+ * Method:    fetch_users
+ * Signature: (J)V
+ */
+#[no_mangle]
+pub extern "system" fn Java_mp_code_Workspace_fetch_1users<'local>(
+	mut env: JNIEnv,
+	_class: JClass<'local>,
+	self_ptr: jlong,
+) {
+	let workspace  = unsafe { Box::leak(Box::from_raw(self_ptr as *mut Workspace)) };
+    RT.block_on(workspace.fetch_users()).jexcept(&mut env);
+}
+
+/*
+ * Class:     mp_code_Workspace
+ * Method:    list_buffer_users
+ * Signature: (JLjava/lang/String;)V
+ */
+#[no_mangle]
+pub extern "system" fn Java_mp_code_Workspace_list_1buffer_1users<'local>(
+	mut env: JNIEnv,
+	_class: JClass<'local>,
+	self_ptr: jlong,
+	input: JString<'local>,
+) {
+	let workspace  = unsafe { Box::leak(Box::from_raw(self_ptr as *mut Workspace)) };
+	let buffer : String = unsafe {
+		env.get_string_unchecked(&input)
+			.expect("Couldn't get java string!")
+			.into()
+	};
+	let users = RT.block_on(workspace.list_buffer_users(&buffer))
+		.jexcept(&mut env)
+		.into_iter()
+		.map(|x| x.id.to_string())
+		.collect::<Vec<String>>();
+	todo!() // how to return Vec<String>?
+}
+
+/*
+ * Class:     mp_code_Workspace
+ * Method:    delete_buffer
+ * Signature: (JLjava/lang/String;)V
+ */
+#[no_mangle]
+pub extern "system" fn Java_mp_code_Workspace_delete_1buffer<'local>(
+	mut env: JNIEnv,
+	_class: JClass<'local>,
+	self_ptr: jlong,
+	input: JString<'local>,
+) {
+	let buffer : String = unsafe {
+		env.get_string_unchecked(&input)
+			.expect("Couldn't get java string!")
+			.into()
+	};
+	let workspace  = unsafe { Box::leak(Box::from_raw(self_ptr as *mut Workspace)) };
+	RT.block_on(workspace.delete(&buffer)).jexcept(&mut env);
+}