json create in `const char* json = _Util_readFile(path, &length);`

in this function it use:

    char* _Util_readFile (const char* path, int* length) {
    	unsigned long size;
        char* data = reinterpret_cast<char*>(FileUtils::getInstance()->getFileData(
    		FileUtils::getInstance()->fullPathForFilename(path).c_str(), "r", &size));
    	*length = size;
    	return data;
    }

`getFileData()` need `delete []`