where is the jni wrapper

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thanks for a lot and i think this python script is so cool!

i found many data structures cannot be auto generated. For example, class Mat. And i find its native java declaration in modules/core/misc/java/core+Mat.java, but i could not find its jni wrapper, Could you tell me if you know. Thank you very much!

"i found many data structures cannot be auto generated" -- indeed.

"but i could not find its jni wrapper" -- did you miss: opencv\modules\java\generator\src\cpp?

yeah i found something related in module/java/generator/src/cpp/Mat.cpp, but the function name there is strange. For example, Java_org_opencv_core_Mat_n_1Mat__DDIDDDD, i don't understand what is the meaning of the string DDIDDDD and i could not find the corresponding name with java native declaration. I think they are what i am searching but do not understand the name changing.

search for "jni naming conventions" oe "jni name mangling"

also described here

those are the argument types, Double, Double, Int, ...

it's meant to be understood by a compiler, not a human ;)

Thanks, i saw that III is explained to a signature in that website link. So two more questions:

1. JNIEXPORT jlong JNICALL Java_org_opencv_core_Mat_n_1Mat__III (JNIEnv* env, jclass, jint rows, jint cols, jint type); is the jni wrapper of java method private static native long n_Mat(int rows, int cols, int type);, right? i am still a little confused because i think the function name should be JNIEXPORT jlong JNICALL Java_org_opencv_core_Mat_n_Mat, without the number 1 and the signature III.
2. In function JNIEXPORT jlong JNICALL Java_org_opencv_core_Mat_n_1Mat__III, there is a line return (jlong) new Mat( rows, cols, type );, how could Mat converted to long? because i didn't see user-defined conversation like operator long() in class mat.

i am sorry for the second question because it is silly. The new operation will return a pointer so it is valid to convert Mat * to long.

thanks. I have solved the first question by reading the document oracle, _1 is escape sequence standing for _, so n_1Mat in jni stands for n_Mat in c/c++. And in jni, overloaded native methods should be followed by two underscores (“__”) , then followed by the mangled argument signature.

i don't think, your 2nd question is silly. it probably takes anyone a deep breath, to dig that pointers are "just a number" ;)