Android NDK文件读取 读写 操作 NDK数据加密DEMO

#include <jni.h>
#include <string>

#define LOG_TAG "xyh"
#include <android/log.h>
#include <stdio.h>


#define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG,__VA_ARGS__)


extern "C" JNIEXPORT jint JNICALL
Java_com_yilun_app_MainActivity_getStrFromNative(
        JNIEnv* env,
        jobject,
        jstring abc/* this */) {
    std::string hello = "Hello from C++";

    FILE* file = fopen("/sdcard/hello.txt", "wt+");
    if(file == NULL){
        LOGD("error open return !");
        return 0;
    }
    fseek(file,0,SEEK_SET);

    char context[20];
    rewind(file);
    fgets(context,20,file);

    if(strlen(context) < 10){