Create `IsNull` helper trait

3 files changed, 22 insertions, 3 deletions

diff --git a/mullvad-jni/src/from_java.rs b/mullvad-jni/src/from_java.rs
index 186079ca77..8ef615242e 100644
--- a/mullvad-jni/src/from_java.rs
+++ b/mullvad-jni/src/from_java.rs
@@ -1,10 +1,10 @@
-use crate::get_class;
+use crate::{get_class, is_null::IsNull};
 use jni::{
     objects::{JObject, JString},
     JNIEnv,
 };
 use mullvad_types::relay_constraints::{Constraint, LocationConstraint};
-use std::{fmt::Debug, ops::Deref};
+use std::fmt::Debug;
 
 pub trait FromJava<'env> {
     type JavaType: 'env;
@@ -15,7 +15,7 @@ pub trait FromJava<'env> {
 impl<'env, T> FromJava<'env> for Option<T>
 where
     T: FromJava<'env>,
-    T::JavaType: Deref<Target = JObject<'env>>,
+    T::JavaType: IsNull,
 {
     type JavaType = T::JavaType;
 
diff --git a/mullvad-jni/src/is_null.rs b/mullvad-jni/src/is_null.rs
new file mode 100644
index 0000000000..628fc4c81a
--- /dev/null
+++ b/mullvad-jni/src/is_null.rs
@@ -0,0 +1,18 @@
+use jni::objects::{JObject, JString};
+use std::ops::Deref;
+
+pub trait IsNull {
+    fn is_null(&self) -> bool;
+}
+
+impl<'a> IsNull for JObject<'a> {
+    fn is_null(&self) -> bool {
+        self.deref().is_null()
+    }
+}
+
+impl<'a> IsNull for JString<'a> {
+    fn is_null(&self) -> bool {
+        self.deref().is_null()
+    }
+}
diff --git a/mullvad-jni/src/lib.rs b/mullvad-jni/src/lib.rs
index 91a83f09cd..0b512a750c 100644
--- a/mullvad-jni/src/lib.rs
+++ b/mullvad-jni/src/lib.rs
@@ -3,6 +3,7 @@
 mod daemon_interface;
 mod from_java;
 mod into_java;
+mod is_null;
 
 use crate::{daemon_interface::DaemonInterface, from_java::FromJava, into_java::IntoJava};
 use jni::{