为jniapp添加lib到makefile-Addlibtomakefileforjniapp

I don't understand how to run c++ code in java using JNI. I think there's some error in the makefile, I think some lib are missing.

我不明白如何使用JNI在java中运行c ++代码。我认为makefile中有一些错误,我认为有些lib丢失了。

I have this code in java class:

我在java类中有这个代码:

private native void getCanny(long mat);
getCanny(mat.getNativeObjAddr());

and the Mat2Image.h generated:

和Mat2Image.h生成:

/* DO NOT EDIT THIS FILE - it is machine generated */
#include 
/* Header for class Mat2Image */

#ifndef _Included_Mat2Image
#define _Included_Mat2Image
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     Mat2Image
 * Method:    getCanny
 * Signature: (J)V
 */
JNIEXPORT void JNICALL Java_Mat2Image_getCanny
  (JNIEnv *, jobject, jlong);

#ifdef __cplusplus
}
#endif
#endif

and this is the .cpp I've made:

这是我制作的.cpp:

#include "Mat2Image.h"
#include 
#include 
#include 


JNIEXPORT void JNICALL Java_Mat2Image_getCanny
   (JNIEnv * env, jobject obj, jlong matr){


       cv::Mat* frame=(cv::Mat*)matr;
            cv::cvtColor(*frame, *frame, CV_BGR2GRAY);
            cv::GaussianBlur(*frame, *frame, cv::Size(7,7), 1.5, 1.5);
            cv::Canny(*frame, *frame, 0, 30, 3);


}

and this is my makefile:

这是我的makefile:

# Define a variable for classpath
CLASS_PATH = ../bin

# Debug: -g3=compile with extra debugg infos. -ggdbg3=include things like macro defenitions. -O0=turn off optimizations.
DEBUGFLAGS = -g3 -ggdb3 -O0
CFLAGS = $(DEBUGFLAGS)

# Define a virtual path for .class in the bin directory
vpath %.class $(CLASS_PATH)

all : libMat.so

# $@ matches the target, $

/usr/lib/jvm/jdk1.8.0_111/bin/java: symbol lookup error: /home/buzzo/Downloads/helloJni-master/jni/libMat.so: undefined symbol: _ZN2cv8cvtColorERKNS_11_InputArrayERKNS_12_OutputArrayEii

libMat.so : libMat.o
    g++ $(CFLAGS) -W -shared -o $@ $<

libMat.so : libMat.o
    g++ $(CFLAGS) -W -shared -o $@ $<-lopencv_imgproc

# Define a variable for classpath
CLASS_PATH = ../bin
# Debug: -g3=compile with extra debugg infos. -ggdbg3=include things like macro defenitions. -O0=turn off optimizations.
DEBUGFLAGS = -g3 -ggdb3 -O0
CFLAGS = $(DEBUGFLAGS)

# Define a virtual path for .class in the bin directory
vpath %.class $(CLASS_PATH)

all : libMat.so

# $@ matches the target, $