Generate null-safe java code

pkgs/jni/lib/jni_symbols.yaml

@@ -4,71 +4,86 @@ files:
     'java.lang.Object':
       name: JObject
       type_class: JObjectType
+      nullable_type_class: JObjectNullableType
       super_count: 0
     'java.lang.String':
       name: JString
       type_class: JStringType
+      nullable_type_class: JStringNullableType
       super_count: 1
     'java.lang.Number':
       name: JNumber
       type_class: JNumberType
+      nullable_type_class: JNumberNullableType
       super_count: 1
     'java.lang.Byte':
       name: JByte
       type_class: JByteType
+      nullable_type_class: JByteNullableType
       super_count: 2
     'java.lang.Short':
       name: JShort
       type_class: JShortType
+      nullable_type_class: JShortNullableType
       super_count: 2
     'java.lang.Integer':
       name: JInteger
       type_class: JIntegerType
+      nullable_type_class: JIntegerNullableType
       super_count: 2
     'java.lang.Long':
       name: JLong
       type_class: JLongType
+      nullable_type_class: JLongNullableType
       super_count: 2
     'java.lang.Float':
       name: JFloat
       type_class: JFloatType
+      nullable_type_class: JFloatNullableType
       super_count: 2
     'java.lang.Double':
       name: JDouble
       type_class: JDoubleType
+      nullable_type_class: JDoubleNullableType
       super_count: 2
     'java.lang.Boolean':
       name: JBoolean
       type_class: JBooleanType
+      nullable_type_class: JBooleanNullableType
       super_count: 1
     'java.lang.Character':
       name: JCharacter
       type_class: JCharacterType
+      nullable_type_class: JCharacterNullableType
       super_count: 1
     'java.util.Set':
       name: JSet
       type_class: JSetType
+      nullable_type_class: JSetNullableType
       super_count: 1
       type_params:
         E:
           'java.lang.Object': DECLARED
     'java.util.List':
       name: JList
       type_class: JListType
+      nullable_type_class: JListNullableType
       super_count: 1
       type_params:
         E:
           'java.lang.Object': DECLARED
     'java.util.Iterator':
       name: JIterator
       type_class: JIteratorType
+      nullable_type_class: JIteratorNullableType
       super_count: 1
       type_params:
         E:
           'java.lang.Object': DECLARED
     'java.util.Map':
       name: JMap
       type_class: JMapType
+      nullable_type_class: JMapNullableType
       super_count: 1
       type_params:
         K:
@@ -78,8 +93,10 @@ files:
     'java.nio.Buffer':
       name: JBuffer
       type_class: JBufferType
+      nullable_type_class: JBufferNullableType
       super_count: 1
     'java.nio.ByteBuffer':
       name: JByteBuffer
       type_class: JByteBufferType
+      nullable_type_class: JByteBufferNullableType
       super_count: 2

pkgs/jni/lib/src/accessors.dart

@@ -67,7 +67,7 @@ extension JniResultMethods on JniResult {
     return pointer == nullptr ? jNullReference : JGlobalReference(pointer);
   }
 
-  T object<T extends JObject>(JObjType<T> type) {
+  T object<T extends JObject?>(JObjType<T> type) {
     return type.fromReference(reference);
   }
 

pkgs/jni/lib/src/jobject.dart

@@ -115,8 +115,6 @@ class JObject {
     return JClass.fromReference(JGlobalReference(classRef));
   }
 
-  bool get isNull => reference.isNull;
-
   /// Releases the underlying [reference].
   ///
   /// Releasing in one isolate while using or releasing in another isolate might

pkgs/jni/lib/src/util/jlist.dart

@@ -14,13 +14,13 @@ import '../types.dart';
 import 'jiterator.dart';
 import 'jset.dart';
 
-final class JNullableListType<$E extends JObject?>
+final class JListNullableType<$E extends JObject?>
     extends JObjType<JList<$E>?> {
   @internal
   final JObjType<$E> E;
 
   @internal
-  const JNullableListType(
+  const JListNullableType(
     this.E,
   );
 
@@ -46,12 +46,12 @@ final class JNullableListType<$E extends JObject?>
   final superCount = 1;
 
   @override
-  int get hashCode => Object.hash(JNullableListType, E);
+  int get hashCode => Object.hash(JListNullableType, E);
 
   @override
   bool operator ==(Object other) {
-    return other.runtimeType == (JNullableListType<$E>) &&
-        other is JNullableListType<$E> &&
+    return other.runtimeType == (JListNullableType<$E>) &&
+        other is JListNullableType<$E> &&
         E == other.E;
   }
 }
@@ -80,7 +80,7 @@ final class JListType<$E extends JObject?> extends JObjType<JList<$E>> {
 
   @internal
   @override
-  JObjType<JList<$E>?> get nullableType => JNullableListType<$E>(E);
+  JObjType<JList<$E>?> get nullableType => JListNullableType<$E>(E);
 
   @internal
   @override

pkgs/jni/lib/src/util/jmap.dart

@@ -11,7 +11,7 @@ import '../jreference.dart';
 import '../types.dart';
 import 'jset.dart';
 
-final class JNullableMapType<$K extends JObject?, $V extends JObject?>
+final class JMapNullableType<$K extends JObject?, $V extends JObject?>
     extends JObjType<JMap<$K, $V>?> {
   @internal
   final JObjType<$K> K;
@@ -20,7 +20,7 @@ final class JNullableMapType<$K extends JObject?, $V extends JObject?>
   final JObjType<$V> V;
 
   @internal
-  const JNullableMapType(
+  const JMapNullableType(
     this.K,
     this.V,
   );
@@ -47,12 +47,12 @@ final class JNullableMapType<$K extends JObject?, $V extends JObject?>
   final superCount = 1;
 
   @override
-  int get hashCode => Object.hash(JNullableMapType, K, V);
+  int get hashCode => Object.hash(JMapNullableType, K, V);
 
   @override
   bool operator ==(Object other) {
-    return other.runtimeType == (JNullableMapType<$K, $V>) &&
-        other is JNullableMapType<$K, $V> &&
+    return other.runtimeType == (JMapNullableType<$K, $V>) &&
+        other is JMapNullableType<$K, $V> &&
         K == other.K &&
         V == other.V;
   }
@@ -87,7 +87,7 @@ final class JMapType<$K extends JObject?, $V extends JObject?>
 
   @internal
   @override
-  JObjType<JMap<$K, $V>?> get nullableType => JNullableMapType<$K, $V>(K, V);
+  JObjType<JMap<$K, $V>?> get nullableType => JMapNullableType<$K, $V>(K, V);
 
   @internal
   @override