Implement `FromJava` for `Constraint`

4 files changed, 52 insertions, 5 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 0744c310ca..ccf2d2491f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -698,7 +698,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "jni"
-version = "0.11.0"
+version = "0.12.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cesu8 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1166,7 +1166,7 @@ version = "0.1.0"
 dependencies = [
  "err-derive 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
- "jni 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jni 0.12.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "jsonrpc-client-core 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2847,7 +2847,7 @@ dependencies = [
 "checksum ipnetwork 0.14.0 (git+https://github.com/mullvad/ipnetwork?branch=fix-deserialization)" = "<none>"
 "checksum ipnetwork 0.14.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b3d862c86f7867f19b693ec86765e0252d82e53d4240b9b629815675a0714ad1"
 "checksum itoa 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "1306f3464951f30e30d12373d31c79fbd52d236e5e896fd92f96ec7babbbe60b"
-"checksum jni 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "294eca097d1dc0bf59de5ab9f7eafa5f77129e9f6464c957ed3ddeb705fb4292"
+"checksum jni 0.12.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f6a88aedffe8ad596237d23a363a53a6c7c6493d4918864d47673e6a15eb938b"
 "checksum jni-sys 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8eaf4bc02d17cbdd7ff4c7438cafcdf7fb9a4613313ad11b4f8fefe7d3fa0130"
 "checksum jsonrpc-client-core 0.5.0 (git+https://github.com/mullvad/jsonrpc-client-rs?rev=68aac55b)" = "<none>"
 "checksum jsonrpc-client-core 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f29cb249837420fb0cee7fb0fbf1d22679e121b160e71bb5e0d90b9df241c23e"
diff --git a/mullvad-jni/Cargo.toml b/mullvad-jni/Cargo.toml
index a9b8092d92..bfb4cd7ede 100644
--- a/mullvad-jni/Cargo.toml
+++ b/mullvad-jni/Cargo.toml
@@ -12,7 +12,7 @@ crate_type = ["cdylib"]
 [dependencies]
 err-derive = "0.1.5"
 futures = "0.1"
-jni = "0.11"
+jni = "0.12"
 jsonrpc-client-core = "0.5"
 lazy_static = "1"
 log = "0.4"
diff --git a/mullvad-jni/src/from_java.rs b/mullvad-jni/src/from_java.rs
index 11b98ad753..7a87e10884 100644
--- a/mullvad-jni/src/from_java.rs
+++ b/mullvad-jni/src/from_java.rs
@@ -1,8 +1,10 @@
+use crate::get_class;
 use jni::{
     objects::{JObject, JString},
     JNIEnv,
 };
-use std::ops::Deref;
+use mullvad_types::relay_constraints::Constraint;
+use std::{fmt::Debug, ops::Deref};
 
 pub trait FromJava<'env> {
     type JavaType: 'env;
@@ -36,3 +38,46 @@ impl<'env> FromJava<'env> for String {
         )
     }
 }
+
+impl<'env, T> FromJava<'env> for Constraint<T>
+where
+    T: Clone + Debug + Eq + FromJava<'env>,
+    T::JavaType: From<JObject<'env>>,
+{
+    type JavaType = JObject<'env>;
+
+    fn from_java(env: &JNIEnv<'env>, source: Self::JavaType) -> Self {
+        if is_instance_of(env, source, "net/mullvad/mullvadvpn/model/Constraint$Any") {
+            Constraint::Any
+        } else if is_instance_of(env, source, "net/mullvad/mullvadvpn/model/Constraint$Only") {
+            let value = get_object_field(env, source, "value", "Ljava/lang/Object;");
+
+            Constraint::Only(T::from_java(env, T::JavaType::from(value)))
+        } else {
+            panic!("Invalid Constraint Java sub-class");
+        }
+    }
+}
+
+fn is_instance_of<'env>(
+    env: &JNIEnv<'env>,
+    object: JObject<'env>,
+    class_name: &'static str,
+) -> bool {
+    let class = get_class(class_name);
+
+    env.is_instance_of(object, &class)
+        .expect("Failed to check if an object is an instance of a specified class")
+}
+
+fn get_object_field<'env>(
+    env: &JNIEnv<'env>,
+    object: JObject<'env>,
+    field_name: &str,
+    field_type: &str,
+) -> JObject<'env> {
+    env.get_field(object, field_name, field_type)
+        .expect("Failed to get field from object")
+        .l()
+        .expect("Field has incorrect Java type")
+}
diff --git a/mullvad-jni/src/lib.rs b/mullvad-jni/src/lib.rs
index 95fccfb5ce..fdd6062cc4 100644
--- a/mullvad-jni/src/lib.rs
+++ b/mullvad-jni/src/lib.rs
@@ -21,6 +21,8 @@ const LOG_FILENAME: &str = "daemon.log";
 const CLASSES_TO_LOAD: &[&str] = &[
     "java/util/ArrayList",
     "net/mullvad/mullvadvpn/model/AccountData",
+    "net/mullvad/mullvadvpn/model/Constraint$Any",
+    "net/mullvad/mullvadvpn/model/Constraint$Only",
     "net/mullvad/mullvadvpn/model/Relay",
     "net/mullvad/mullvadvpn/model/RelayList",
     "net/mullvad/mullvadvpn/model/RelayListCity",