将未签名的char *转换为json，jsonspp C ++

Question

I have unsigned char array holding data, I want to store this into a Json object. How can it be done? Using jsoncpp and C++11. the statement

rootL1["CurrentValue"] = userInfo->hashCred;

does not work, in turn it is stored as bool in json instead of the unsigned data.

Answer 1

If you can look into documentation of jsoncpp Value class (I assume rootL1 is of this type, and operator[] returns the same type), you will see that there is no unsigned char* conversion constructor which would accept your userInfo->hashCred array. There is one constructor which accepts const char* but there is no implicit conversion from unsigned char* to const char* , the closest one is implicit conversion of pointer to bool which is choosen in your case.

The solution should be to use conversion constructor which accepts const char* . You should think why you need unsigned char* in the first place, maybe you can use an array of type char ? If you cant then you can try casting unsigned char* to char* :

rootL1["CurrentValue"] = reinterpret_cast<char *>(userInfo->hashCred)

but this can cause all sorts of problems depending on what you are actually storing in your array and also what jsoncpp is doing under the hood with this data.

I would suggest you treat your hashCred as binary data and uuencode it to char array. Then store it in jsoncpp Value. For details look into here: Binary data JSONCPP

In jsoncpp test code you can also find some examples of how to store binary data as values.