[AndroidTip]local reference table overflow (max=512)的错误解决

JNI层coding经常会遇到ReferenceTable overflow问题，特别是当jni函数被反复调用上千上万次的时候，现汇总如下，未完待续，并欢迎补充，(*^__^*) 嘻嘻……

总体原则：释放所有对object的引用

1.FindClass

例如，

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

 env->DeleteLocalRef(ref);

 

2.NewString/ NewStringUTF/NewObject/NewByteArray

例如，

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);

  

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

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

 

5.NewGlobalRef/DeleteGlobalRef

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

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

例如，

jobject ref= env->NewGlobalRef(customObj);

 env->DeleteGlobalRef(customObj);