Java定義：

    public  String  getSignatureInfo() {
        try {
            PackageInfo packageInfo = mContext.getPackageManager().getPackageInfo(mContext.getPackageName(), PackageManager.GET_SIGNATURES);
            android.content.pm.Signature[] signs = packageInfo.signatures;
            android.content.pm.Signature sign = signs[0];
            byte[] signature = sign.toByteArray();

            X509Certificate cert = parseSignature(signature);

            return  getMessageDigest("SHA1", signature);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
 

JNIEXPORT jint JNICALL Java_com_letv_jr_safesignaturelibrary_JrSignature_getCLangString(JNIEnv *env, jobject obj)
{
  //得到類
  jclass clazz=(*env)->GetObjectClass(env,obj);
  if(clazz==0){
    return;
  }
  //快取類
  targetClass=(jclass)(*env)->NewGlobalRef(env,clazz);
  if(targetClass==0){
    return;
  }
  //快取物件
  targetObject=(jobject)(*env)->NewGlobalRef(env,obj);
  if(targetObject==0){
    return;
  }
  //快取方法
  targetMethodID=(*env)->GetMethodID(env,clazz,"getSignatureInfo","()Ljava/lang/String;");
  if(targetMethodID==0){
    return;
  }
  //拿到Java返回值
  jstring pring=(jstring)(*env)->CallObjectMethod(env,obj,targetMethodID);
  //轉換成char型
  char *print=(char *)(*env)->GetStringUTFChars(env,pring,0);
  if (strcmp(secret, print) == 0){
    return 0;
  }else{
    return 1;
  }
}