Android加载机器学习分类器问题，我们用的是较笨的办法即先把文件放在res中然后在程序启动时放到SD卡然后获取SD卡指定路径。
如果大家有好的办法还请回复本文。
先将分类器文件放到res下的raw目录，然后添加代码如下：
//读取分类器文件写入SD卡目录
public void saveToSDCard(String name) throws Throwable {
InputStream inStream = this.getResources().openRawResource(R.raw.haarcascade_frontalface_alt2);
File file = new File(Environment.getExternalStorageDirectory(), name);
path=file.getAbsolutePath();
Log.e("fhh", file.getAbsolutePath());
FileOutputStream fileOutputStream = new FileOutputStream(file);//存入SDCard
byte[] buffer = new byte[1024];
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
int len = 0;
while((len = inStream.read(buffer)) != -1) {
outStream.write(buffer, 0, len);
}
byte[] bs = outStream.toByteArray();
fileOutputStream.write(bs);
outStream.close();
inStream.close();
fileOutputStream.flush();
fileOutputStream.close();
}
用的时候直接将path以jstring传给JNI就可以了，到JNI再转一下即可
char* jstringTostring(JNIEnv* env, jstring jstr)
{
char* rtn = NULL;
jclass clsstring = env->FindClass("java/lang/String");
jstring strencode = env->NewStringUTF("utf-8");
jmethodID mid = env->GetMethodID(clsstring, "getBytes", "(Ljava/lang/String;)[B");
jbyteArray barr= (jbyteArray)env->CallObjectMethod(jstr, mid, strencode);
jsize alen = env->GetArrayLength(barr);
jbyte* ba = env->GetByteArrayElements(barr, JNI_FALSE);
if (alen > 0)
{
rtn = (char*)malloc(alen + 1);
memcpy(rtn, ba, alen);
rtn[alen] = 0;
}
env->ReleaseByteArrayElements(barr, ba, 0);
return rtn;
}