JNI層開發會遇到ReferenceTable overflow問題，特別是當jni函式被反覆呼叫上千上萬次的時候，現彙總如下

對於FindClass 返回的一定需要呼叫DeleteLocalRef，還有如下型別的變數需要DeleteLocalRef：

.FindClass /NewString/ NewStringUTF/NewObject/ GetObjectField等產生的都是LocalRef

總體原則：釋放所有對object的引用。

1.FindClass

jclass ref= (env)->FindClass("java/lang/String");

env->DeleteLocalRef(ref); 

2.NewString/ NewStringUTF/NewObject/NewByteArray

jstring     (*NewString)(JNIEnv*, const jchar*, jsize);    

const jchar* (*GetStringChars)(JNIEnv*, jstring, jboolean*);     

void        (*ReleaseStringChars)(JNIEnv*, jstring, const jchar*);

jstring     (*NewStringUTF)(JNIEnv*, const char*);    

const char* (*GetStringUTFChars)(JNIEnv*, jstring, jboolean*);     

void        (*ReleaseStringUTFChars)(JNIEnv*, jstring, const char*);

env->DeleteLocalRef(ref);

3.GetObjectField/GetObjectClass/GetObjectArrayElement

jclass ref = env->GetObjectClass(robj);

env->DeleteLocalRef(ref); 

4.GetByteArrayElements

jbyte* array= (*env)->GetByteArrayElements(env,jarray,&isCopy);

(*env)->ReleaseByteArrayElements(env,jarray,array,0);

5.const char* input =(*env)->GetStringUTFChars(env,jinput, &isCopy);

(*env)->ReleaseStringUTFChars(env,jinput,input);

6.NewGlobalRef/DeleteGlobalRef

 jobject     (*NewGlobalRef)(JNIEnv*, jobject);     

void        (*DeleteGlobalRef)(JNIEnv*, jobject);

例如，

jobject ref= env->NewGlobalRef(customObj);

env->DeleteGlobalRef(customObj);