Use SmartLocalRef to automatically release localrefs in jassimp.cpp

- Add SmartLocalRef class
- Use it to automatically delete localrefs of Java objects, generated
  by FindClass, createInstance, getField, NewStringUTF, etc.
- Tested with models with more than 512 nodes.

diff --git a/port/jassimp/jassimp-native/src/jassimp.cpp b/port/jassimp/jassimp-native/src/jassimp.cpp
index 8093db7..4b9dba3 100644 (file)
--- a/port/jassimp/jassimp-native/src/jassimp.cpp
+++ b/port/jassimp/jassimp-native/src/jassimp.cpp
@@ -15,9 +15,24 @@
 #define lprintf
 #endif
 
+// Automatically deletes a local ref when it goes out of scope
+class SmartLocalRef {
+private:
+    JNIEnv* mJniEnv;
+    jobject& mJavaObj;
+public:
+    template<class T> SmartLocalRef(JNIEnv* env, T& object) : mJniEnv(env), mJavaObj((jobject&)object) {};
+    ~SmartLocalRef() {
+        if (mJavaObj != NULL) {
+            mJniEnv->DeleteLocalRef(mJavaObj);
+        }
+    }
+};
+
 static bool createInstance(JNIEnv *env, const char* className, jobject& newInstance)
 {
        jclass clazz = env->FindClass(className);
+       SmartLocalRef clazzRef(env, clazz);
 
        if (NULL == clazz)
        {
@@ -34,7 +49,6 @@ static bool createInstance(JNIEnv *env, const char* className, jobject& newInsta
        }
 
        newInstance = env->NewObject(clazz, ctr_id);
-       env->DeleteLocalRef(clazz);
 
        if (NULL == newInstance) 
        {
@@ -49,6 +63,7 @@ static bool createInstance(JNIEnv *env, const char* className, jobject& newInsta
 static bool createInstance(JNIEnv *env, const char* className, const char* signature,/* const*/ jvalue* params, jobject& newInstance)
 {
        jclass clazz = env->FindClass(className);
+       SmartLocalRef clazzRef(env, clazz);
 
        if (NULL == clazz)
        {
@@ -65,7 +80,6 @@ static bool createInstance(JNIEnv *env, const char* className, const char* signa
        }
 
        newInstance = env->NewObjectA(clazz, ctr_id, params);
-       env->DeleteLocalRef(clazz);
 
        if (NULL == newInstance) 
        {
@@ -80,6 +94,7 @@ static bool createInstance(JNIEnv *env, const char* className, const char* signa
 static bool getField(JNIEnv *env, jobject object, const char* fieldName, const char* signature, jobject& field)
 {
        jclass clazz = env->GetObjectClass(object);
+       SmartLocalRef clazzRef(env, clazz);
 
        if (NULL == clazz)
        {
@@ -88,7 +103,6 @@ static bool getField(JNIEnv *env, jobject object, const char* fieldName, const c
        }
 
        jfieldID fieldId = env->GetFieldID(clazz, fieldName, signature);
-       env->DeleteLocalRef(clazz);
 
        if (NULL == fieldId)
        {
@@ -105,6 +119,7 @@ static bool getField(JNIEnv *env, jobject object, const char* fieldName, const c
 static bool setIntField(JNIEnv *env, jobject object, const char* fieldName, jint value)
 {
        jclass clazz = env->GetObjectClass(object);
+       SmartLocalRef clazzRef(env, clazz);
 
        if (NULL == clazz)
        {
@@ -113,7 +128,6 @@ static bool setIntField(JNIEnv *env, jobject object, const char* fieldName, jint
        }
 
        jfieldID fieldId = env->GetFieldID(clazz, fieldName, "I");
-       env->DeleteLocalRef(clazz);
 
        if (NULL == fieldId)
        {
@@ -130,6 +144,7 @@ static bool setIntField(JNIEnv *env, jobject object, const char* fieldName, jint
 static bool setFloatField(JNIEnv *env, jobject object, const char* fieldName, jfloat value)
 {
        jclass clazz = env->GetObjectClass(object);
+       SmartLocalRef clazzRef(env, clazz);
 
        if (NULL == clazz)
        {
@@ -138,7 +153,6 @@ static bool setFloatField(JNIEnv *env, jobject object, const char* fieldName, jf
        }
 
        jfieldID fieldId = env->GetFieldID(clazz, fieldName, "F");
-       env->DeleteLocalRef(clazz);
 
        if (NULL == fieldId)
        {
@@ -155,6 +169,7 @@ static bool setFloatField(JNIEnv *env, jobject object, const char* fieldName, jf
 static bool setObjectField(JNIEnv *env, jobject object, const char* fieldName, const char* signature, jobject value)
 {
        jclass clazz = env->GetObjectClass(object);
+       SmartLocalRef clazzRef(env, clazz);
 
        if (NULL == clazz)
        {
@@ -163,7 +178,6 @@ static bool setObjectField(JNIEnv *env, jobject object, const char* fieldName, c
        }
 
        jfieldID fieldId = env->GetFieldID(clazz, fieldName, signature);
-       env->DeleteLocalRef(clazz);
 
        if (NULL == fieldId)
        {
@@ -180,6 +194,7 @@ static bool setObjectField(JNIEnv *env, jobject object, const char* fieldName, c
 static bool getStaticField(JNIEnv *env, const char* className, const char* fieldName, const char* signature, jobject& field)
 {
        jclass clazz = env->FindClass(className);
+       SmartLocalRef clazzRef(env, clazz);
 
        if (NULL == clazz)
        {
@@ -205,6 +220,7 @@ static bool call(JNIEnv *env, jobject object, const char* typeName, const char*
        const char* signature,/* const*/ jvalue* params)
 {
        jclass clazz = env->FindClass(typeName);
+       SmartLocalRef clazzRef(env, clazz);
 
        if (NULL == clazz)
        {
@@ -213,7 +229,6 @@ static bool call(JNIEnv *env, jobject object, const char* typeName, const char*
        }
 
        jmethodID mid = env->GetMethodID(clazz, methodName, signature);
-       env->DeleteLocalRef(clazz);
 
        if (NULL == mid)
        {
@@ -228,6 +243,7 @@ static bool call(JNIEnv *env, jobject object, const char* typeName, const char*
 static bool callv(JNIEnv *env, jobject object, const char* typeName,
                const char* methodName, const char* signature,/* const*/ jvalue* params) {
        jclass clazz = env->FindClass(typeName);
+       SmartLocalRef clazzRef(env, clazz);
 
        if (NULL == clazz) {
                lprintf("could not find class %s\n", typeName);
@@ -235,7 +251,6 @@ static bool callv(JNIEnv *env, jobject object, const char* typeName,
        }
 
        jmethodID mid = env->GetMethodID(clazz, methodName, signature);
-       env->DeleteLocalRef(clazz);
 
        if (NULL == mid) {
                lprintf("could not find method %s with signature %s in type %s\n", methodName, signature, typeName);
@@ -252,6 +267,7 @@ static bool callStaticObject(JNIEnv *env, const char* typeName, const char* meth
        const char* signature,/* const*/ jvalue* params, jobject& returnValue)
 {
        jclass clazz = env->FindClass(typeName);
+       SmartLocalRef clazzRef(env, clazz);
 
        if (NULL == clazz)
        {
@@ -276,6 +292,7 @@ static bool callStaticObject(JNIEnv *env, const char* typeName, const char* meth
 static bool copyBuffer(JNIEnv *env, jobject jMesh, const char* jBufferName, void* cData, size_t size)
 {
        jobject jBuffer = NULL;
+       SmartLocalRef bufferRef(env, jBuffer);
 
        if (!getField(env, jMesh, jBufferName, "Ljava/nio/ByteBuffer;", jBuffer))
        {
@@ -305,6 +322,7 @@ static bool copyBuffer(JNIEnv *env, jobject jMesh, const char* jBufferName, void
 static bool copyBufferArray(JNIEnv *env, jobject jMesh, const char* jBufferName, int index, void* cData, size_t size)
 {
        jobject jBufferArray = NULL;
+       SmartLocalRef bufferArrayRef(env, jBufferArray);
 
        if (!getField(env, jMesh, jBufferName, "[Ljava/nio/ByteBuffer;", jBufferArray))
        {
@@ -312,6 +330,7 @@ static bool copyBufferArray(JNIEnv *env, jobject jMesh, const char* jBufferName,
        }
 
        jobject jBuffer = env->GetObjectArrayElement((jobjectArray) jBufferArray, index);
+       SmartLocalRef bufferRef(env, jBuffer);
 
        if (env->GetDirectBufferCapacity(jBuffer) != size)
        {
@@ -344,6 +363,7 @@ static bool loadMeshes(JNIEnv *env, const aiScene* cScene, jobject& jScene)
 
                /* create mesh */
                jobject jMesh = NULL;
+               SmartLocalRef refMesh(env, jMesh);
 
                if (!createInstance(env, "jassimp/AiMesh", jMesh)) 
                {
@@ -353,6 +373,7 @@ static bool loadMeshes(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                
                /* add mesh to m_meshes java.util.List */
                jobject jMeshes = NULL;
+               SmartLocalRef refMeshes(env, jMeshes);
 
                if (!getField(env, jScene, "m_meshes", "Ljava/util/List;", jMeshes))
                {
@@ -381,7 +402,9 @@ static bool loadMeshes(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                        return false;
                }
 
-               if (!setObjectField(env, jMesh, "m_name", "Ljava/lang/String;", env->NewStringUTF(cMesh->mName.C_Str())))
+               jstring nameString = env->NewStringUTF(cMesh->mName.C_Str());
+               SmartLocalRef refNameString(env, nameString);
+               if (!setObjectField(env, jMesh, "m_name", "Ljava/lang/String;", nameString))
                {
                        return false;
                }
@@ -651,6 +674,7 @@ static bool loadMeshes(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                        aiBone *cBone = cMesh->mBones[b];
 
                        jobject jBone;
+                       SmartLocalRef refBone(env, jBone);
                        if (!createInstance(env, "jassimp/AiBone", jBone)) 
                        {
                                return false;
@@ -658,7 +682,7 @@ static bool loadMeshes(JNIEnv *env, const aiScene* cScene, jobject& jScene)
 
                        /* add bone to bone list */
                        jobject jBones = NULL;
-
+                       SmartLocalRef refBones(env, jBones);
                        if (!getField(env, jMesh, "m_bones", "Ljava/util/List;", jBones))
                        {
                                return false;
@@ -672,7 +696,9 @@ static bool loadMeshes(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                        }
 
                        /* set bone data */
-                       if (!setObjectField(env, jBone, "m_name", "Ljava/lang/String;", env->NewStringUTF(cBone->mName.C_Str())))
+                       jstring boneNameString = env->NewStringUTF(cBone->mName.C_Str());
+                       SmartLocalRef refNameString(env, boneNameString);
+                       if (!setObjectField(env, jBone, "m_name", "Ljava/lang/String;", boneNameString))
                        {
                                return false;
                        }
@@ -681,27 +707,29 @@ static bool loadMeshes(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                        for (unsigned int w = 0; w < cBone->mNumWeights; w++)
                        {
                                jobject jBoneWeight;
-                               if (!createInstance(env, "jassimp/AiBoneWeight", jBoneWeight)) 
+                               SmartLocalRef refBoneWeight(env, jBoneWeight);
+                               if (!createInstance(env, "jassimp/AiBoneWeight", jBoneWeight))
                                {
                                        return false;
                                }
 
                                /* add boneweight to bone list */
                                jobject jBoneWeights = NULL;
-
+                               SmartLocalRef refBoneWeights(env, jBoneWeights);
                                if (!getField(env, jBone, "m_boneWeights", "Ljava/util/List;", jBoneWeights))
                                {
                                        return false;
                                }
 
-
                                /* copy offset matrix */
                                jfloatArray jMatrixArr = env->NewFloatArray(16);
+                               SmartLocalRef refMatrixArr(env, jMatrixArr);
                                env->SetFloatArrayRegion(jMatrixArr, 0, 16, (jfloat*) &cBone->mOffsetMatrix);
 
                                jvalue wrapParams[1];
                                wrapParams[0].l = jMatrixArr;
                                jobject jMatrix;
+                               SmartLocalRef refMatrix(env, jMatrix);
                                
                                if (!callStaticObject(env, "jassimp/Jassimp", "wrapMatrix", "([F)Ljava/lang/Object;", wrapParams, jMatrix))
                                {
@@ -733,8 +761,6 @@ static bool loadMeshes(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                                }
                        }
                }
-               env->DeleteLocalRef(jMeshes);
-               env->DeleteLocalRef(jMesh);
        }
 
        return true;
@@ -747,11 +773,13 @@ static bool loadSceneNode(JNIEnv *env, const aiNode *cNode, jobject parent, jobj
 
        /* wrap matrix */
        jfloatArray jMatrixArr = env->NewFloatArray(16);
+       SmartLocalRef refMatrixArr(env, jMatrixArr);
        env->SetFloatArrayRegion(jMatrixArr, 0, 16, (jfloat*) &cNode->mTransformation);
 
        jvalue wrapMatParams[1];
        wrapMatParams[0].l = jMatrixArr;
        jobject jMatrix;
+       SmartLocalRef refMatrix(env, jMatrix);
                                
        if (!callStaticObject(env, "jassimp/Jassimp", "wrapMatrix", "([F)Ljava/lang/Object;", wrapMatParams, jMatrix))
        {
@@ -761,6 +789,8 @@ static bool loadSceneNode(JNIEnv *env, const aiNode *cNode, jobject parent, jobj
 
        /* create mesh references array */
        jintArray jMeshrefArr = env->NewIntArray(cNode->mNumMeshes);
+       SmartLocalRef refMeshrefArr(env, jMeshrefArr);
+
        jint *temp = (jint*) malloc(sizeof(jint) * cNode->mNumMeshes);
 
        for (unsigned int i = 0; i < cNode->mNumMeshes; i++)
@@ -774,7 +804,7 @@ static bool loadSceneNode(JNIEnv *env, const aiNode *cNode, jobject parent, jobj
 
        /* convert name */
        jstring jNodeName = env->NewStringUTF(cNode->mName.C_Str());
-
+       SmartLocalRef refNodeName(env, jNodeName);
 
        /* wrap scene node */
        jvalue wrapNodeParams[4];
@@ -802,6 +832,8 @@ static bool loadSceneNode(JNIEnv *env, const aiNode *cNode, jobject parent, jobj
        if (NULL != loadedNode)
        {
                *loadedNode = jNode;
+       } else {
+           env->DeleteLocalRef(jNode);
        }
 
        return true;
@@ -815,6 +847,7 @@ static bool loadSceneGraph(JNIEnv *env, const aiScene* cScene, jobject& jScene)
        if (NULL != cScene->mRootNode)
        {
                jobject jRoot;
+               SmartLocalRef refRoot(env, jRoot);
 
                if (!loadSceneNode(env, cScene->mRootNode, NULL, &jRoot))
                {
@@ -842,6 +875,7 @@ static bool loadMaterials(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                lprintf("converting material %d ...\n", m);
 
                jobject jMaterial = NULL;
+               SmartLocalRef refMaterial(env, jMaterial);
 
                if (!createInstance(env, "jassimp/AiMaterial", jMaterial))
                {
@@ -850,6 +884,7 @@ static bool loadMaterials(JNIEnv *env, const aiScene* cScene, jobject& jScene)
 
                /* add material to m_materials java.util.List */
                jobject jMaterials = NULL;
+               SmartLocalRef refMaterials(env, jMaterials);
 
                if (!getField(env, jScene, "m_materials", "Ljava/util/List;", jMaterials))
                {
@@ -894,9 +929,12 @@ static bool loadMaterials(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                        lprintf("   converting property %s ...\n", cProperty->mKey.C_Str());
 
                        jobject jProperty = NULL;
+                       SmartLocalRef refProperty(env, jProperty);
 
                        jvalue constructorParams[5];
-                       constructorParams[0].l = env->NewStringUTF(cProperty->mKey.C_Str());
+                       jstring keyString = env->NewStringUTF(cProperty->mKey.C_Str());
+                       SmartLocalRef refKeyString(env, keyString);
+                       constructorParams[0].l = keyString;
                        constructorParams[1].i = cProperty->mSemantic;
                        constructorParams[2].i = cProperty->mIndex;
                        constructorParams[3].i = cProperty->mType;
@@ -908,6 +946,7 @@ static bool loadMaterials(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                                cProperty->mDataLength == 3 * sizeof(float)) 
                        {
                                jobject jData = NULL;
+                               SmartLocalRef refData(env, jData);
 
                                /* wrap color */
                                jvalue wrapColorParams[3];
@@ -932,6 +971,7 @@ static bool loadMaterials(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                                cProperty->mDataLength == 4 * sizeof(float)) 
                        {
                                jobject jData = NULL;
+                               SmartLocalRef refData(env, jData);
 
                                /* wrap color */
                                jvalue wrapColorParams[4];
@@ -954,6 +994,7 @@ static bool loadMaterials(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                        else if (cProperty->mType == aiPTI_Float && cProperty->mDataLength == sizeof(float)) 
                        {
                                jobject jData = NULL;
+                               SmartLocalRef refData(env, jData);
 
                                jvalue newFloatParams[1];
                                newFloatParams[0].f = ((float*) cProperty->mData)[0];
@@ -972,6 +1013,7 @@ static bool loadMaterials(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                        else if (cProperty->mType == aiPTI_Integer && cProperty->mDataLength == sizeof(int)) 
                        {
                                jobject jData = NULL;
+                               SmartLocalRef refData(env, jData);
 
                                jvalue newIntParams[1];
                                newIntParams[0].i = ((int*) cProperty->mData)[0];
@@ -991,6 +1033,7 @@ static bool loadMaterials(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                        {
                                /* skip length prefix */
                                jobject jData = env->NewStringUTF(cProperty->mData + 4);
+                               SmartLocalRef refData(env, jData);
 
                                constructorParams[4].l = jData;
                                if (!createInstance(env, "jassimp/AiMaterial$Property", "(Ljava/lang/String;IIILjava/lang/Object;)V", 
@@ -1010,7 +1053,7 @@ static bool loadMaterials(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                                }
 
                                jobject jBuffer = NULL;
-
+                               SmartLocalRef refBuffer(env, jBuffer);
                                if (!getField(env, jProperty, "m_data", "Ljava/lang/Object;", jBuffer))
                                {
                                        return false;
@@ -1036,7 +1079,7 @@ static bool loadMaterials(JNIEnv *env, const aiScene* cScene, jobject& jScene)
 
                        /* add property */
                        jobject jProperties = NULL;
-
+                       SmartLocalRef refProperties(env, jProperties);
                        if (!getField(env, jMaterial, "m_properties", "Ljava/util/List;", jProperties))
                        {
                                return false;
@@ -1068,8 +1111,12 @@ static bool loadAnimations(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                lprintf("   converting animation %s ...\n", cAnimation->mName.C_Str());
 
                jobject jAnimation;
+               SmartLocalRef refAnimation(env, jAnimation);
+
                jvalue newAnimParams[3];
-               newAnimParams[0].l = env->NewStringUTF(cAnimation->mName.C_Str());
+               jstring nameString = env->NewStringUTF(cAnimation->mName.C_Str());
+               SmartLocalRef refNameString(env, nameString);
+               newAnimParams[0].l = nameString;
                newAnimParams[1].d = cAnimation->mDuration;
                newAnimParams[2].d = cAnimation->mTicksPerSecond;
 
@@ -1080,6 +1127,7 @@ static bool loadAnimations(JNIEnv *env, const aiScene* cScene, jobject& jScene)
 
                /* add animation to m_animations java.util.List */
                jobject jAnimations = NULL;
+               SmartLocalRef refAnimations(env, jAnimations);
 
                if (!getField(env, jScene, "m_animations", "Ljava/util/List;", jAnimations))
                {
@@ -1099,8 +1147,12 @@ static bool loadAnimations(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                        const aiNodeAnim *cNodeAnim = cAnimation->mChannels[c];
 
                        jobject jNodeAnim;
+                       SmartLocalRef refNodeAnim(env, jNodeAnim);
+
                        jvalue newNodeAnimParams[6];
-                       newNodeAnimParams[0].l = env->NewStringUTF(cNodeAnim->mNodeName.C_Str());
+                       jstring animationName = env->NewStringUTF(cNodeAnim->mNodeName.C_Str());
+                       SmartLocalRef refAnimationName(env, animationName);
+                       newNodeAnimParams[0].l = animationName;
                        newNodeAnimParams[1].i = cNodeAnim->mNumPositionKeys;
                        newNodeAnimParams[2].i = cNodeAnim->mNumRotationKeys;
                        newNodeAnimParams[3].i = cNodeAnim->mNumScalingKeys;
@@ -1115,6 +1167,7 @@ static bool loadAnimations(JNIEnv *env, const aiScene* cScene, jobject& jScene)
 
                        /* add nodeanim to m_animations java.util.List */
                        jobject jNodeAnims = NULL;
+                       SmartLocalRef refNodeAnims(env, jNodeAnims);
 
                        if (!getField(env, jAnimation, "m_nodeAnims", "Ljava/util/List;", jNodeAnims))
                        {
@@ -1171,6 +1224,7 @@ static bool loadLights(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                wrapColorParams[1].f = cLight->mColorDiffuse.g;
                wrapColorParams[2].f = cLight->mColorDiffuse.b;
                jobject jDiffuse;
+               SmartLocalRef refDiffuse(env, jDiffuse);
                if (!callStaticObject(env, "jassimp/Jassimp", "wrapColor3", "(FFF)Ljava/lang/Object;", wrapColorParams, jDiffuse))
                {
                        return false;
@@ -1180,6 +1234,7 @@ static bool loadLights(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                wrapColorParams[1].f = cLight->mColorSpecular.g;
                wrapColorParams[2].f = cLight->mColorSpecular.b;
                jobject jSpecular;
+               SmartLocalRef refSpecular(env, jSpecular);
                if (!callStaticObject(env, "jassimp/Jassimp", "wrapColor3", "(FFF)Ljava/lang/Object;", wrapColorParams, jSpecular))
                {
                        return false;
@@ -1189,6 +1244,7 @@ static bool loadLights(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                wrapColorParams[1].f = cLight->mColorAmbient.g;
                wrapColorParams[2].f = cLight->mColorAmbient.b;
                jobject jAmbient;
+               SmartLocalRef refAmbient(env, jAmbient);
                if (!callStaticObject(env, "jassimp/Jassimp", "wrapColor3", "(FFF)Ljava/lang/Object;", wrapColorParams, jAmbient))
                {
                        return false;
@@ -1201,6 +1257,7 @@ static bool loadLights(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                wrapVec3Params[1].f = cLight->mPosition.y;
                wrapVec3Params[2].f = cLight->mPosition.z;
                jobject jPosition;
+               SmartLocalRef refPosition(env, jPosition);
                if (!callStaticObject(env, "jassimp/Jassimp", "wrapVec3", "(FFF)Ljava/lang/Object;", wrapVec3Params, jPosition))
                {
                        return false;
@@ -1210,6 +1267,7 @@ static bool loadLights(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                wrapVec3Params[1].f = cLight->mPosition.y;
                wrapVec3Params[2].f = cLight->mPosition.z;
                jobject jDirection;
+               SmartLocalRef refDirection(env, jDirection);
                if (!callStaticObject(env, "jassimp/Jassimp", "wrapVec3", "(FFF)Ljava/lang/Object;", wrapVec3Params, jDirection))
                {
                        return false;
@@ -1217,9 +1275,11 @@ static bool loadLights(JNIEnv *env, const aiScene* cScene, jobject& jScene)
 
 
                jobject jLight;
-
+               SmartLocalRef refLight(env, jLight);
                jvalue params[12];
-               params[0].l = env->NewStringUTF(cLight->mName.C_Str());;
+               jstring lightName = env->NewStringUTF(cLight->mName.C_Str());
+               SmartLocalRef refLightName(env, lightName);
+               params[0].l = lightName;
                params[1].i = cLight->mType;
                params[2].l = jPosition;
                params[3].l = jDirection;
@@ -1240,6 +1300,7 @@ static bool loadLights(JNIEnv *env, const aiScene* cScene, jobject& jScene)
 
                /* add light to m_lights java.util.List */
                jobject jLights = NULL;
+               SmartLocalRef refLights(env, jLights);
 
                if (!getField(env, jScene, "m_lights", "Ljava/util/List;", jLights))
                {
@@ -1276,6 +1337,7 @@ static bool loadCameras(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                wrapPositionParams[1].f = cCamera->mPosition.y;
                wrapPositionParams[2].f = cCamera->mPosition.z;
                jobject jPosition;
+               SmartLocalRef refPosition(env, jPosition);
                if (!callStaticObject(env, "jassimp/Jassimp", "wrapVec3", "(FFF)Ljava/lang/Object;", wrapPositionParams, jPosition))
                {
                        return false;
@@ -1285,6 +1347,7 @@ static bool loadCameras(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                wrapPositionParams[1].f = cCamera->mUp.y;
                wrapPositionParams[2].f = cCamera->mUp.z;
                jobject jUp;
+               SmartLocalRef refUp(env, jUp);
                if (!callStaticObject(env, "jassimp/Jassimp", "wrapVec3", "(FFF)Ljava/lang/Object;", wrapPositionParams, jUp))
                {
                        return false;
@@ -1294,6 +1357,7 @@ static bool loadCameras(JNIEnv *env, const aiScene* cScene, jobject& jScene)
                wrapPositionParams[1].f = cCamera->mLookAt.y;
                wrapPositionParams[2].f = cCamera->mLookAt.z;
                jobject jLookAt;
+               SmartLocalRef refLookAt(env, jLookAt);
                if (!callStaticObject(env, "jassimp/Jassimp", "wrapVec3", "(FFF)Ljava/lang/Object;", wrapPositionParams, jLookAt))
                {
                        return false;
@@ -1301,9 +1365,12 @@ static bool loadCameras(JNIEnv *env, const aiScene* cScene, jobject& jScene)
 
 
                jobject jCamera;
+               SmartLocalRef refCamera(env, jCamera);
 
                jvalue params[8];
-               params[0].l = env->NewStringUTF(cCamera->mName.C_Str());
+               jstring cameraName = env->NewStringUTF(cCamera->mName.C_Str());
+               SmartLocalRef refCameraName(env, cameraName);
+               params[0].l = cameraName;
                params[1].l = jPosition;
                params[2].l = jUp;
                params[3].l = jLookAt;
@@ -1320,7 +1387,7 @@ static bool loadCameras(JNIEnv *env, const aiScene* cScene, jobject& jScene)
 
                /* add camera to m_cameras java.util.List */
                jobject jCameras = NULL;
-
+               SmartLocalRef refCameras(env, jCameras);
                if (!getField(env, jScene, "m_cameras", "Ljava/util/List;", jCameras))
                {
                        return false;