快速JSON失败，断言`IsObject（）'失败

Question

我想解析从RapidJSON服务器接收到的数据。以下是收到确切的字符串：

[ 
    { 
    "Node": "9478149a08f9", 
    "Address": "172.17.0.2", 
    "ServiceID": "HSS", 
    "ServiceName": "HSS", 
    "ServiceTags": [], 
    "ServiceAddress": "", 
    "ServicePort": 6666, 
    "ServiceEnableTagOverride": false, 
    "CreateIndex": 2855, 
    "ModifyIndex": 2855 
    } 
] 

以下是代码

int main(void) 
{ 
    CURL *curl; 
    CURLcode res; 

    struct MemoryStruct chunk; 

    chunk.memory = (char *)malloc(1); /* will be grown as needed by the realloc above */ 
    chunk.size = 0; /* no data at this point */ 

    /* In windows, this will init the winsock stuff */ 
    curl_global_init(CURL_GLOBAL_ALL); 

    /* get a curl handle */ 
    curl = curl_easy_init(); 
    if(curl) { 
    /* First set the URL that is about to receive our POST. This URL can 
     just as well be a https:// URL if that is what should receive the 
     data. */ 
    curl_easy_setopt(curl, CURLOPT_URL, "http://localhost:8500/v1/catalog/service/HSS"); 
    /* Now specify the POST data */ 

    // Set the callbackfunction to handle the JSON string 
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writefunc); 
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &chunk); 
    /* Perform the request, res will get the return code */ 
    res = curl_easy_perform(curl); 
    /* Check for errors */ 
    if(res != CURLE_OK) 
     fprintf(stderr, "curl_easy_perform() failed: %s\n", 
       curl_easy_strerror(res)); 

    /* always cleanup */ 
    curl_easy_cleanup(curl); 
    } 

    std::string str; 
    str.assign(chunk.memory,chunk.size); 

    cout<<"The string response is :"<<str<<endl; 
    Document d; 
    d.Parse(str.c_str()); 

    assert(d.IsObject()); 

< - 它无法在这里

的JSON数据是有效的，但不知道为什么它仍然失败。

Answer 1

您的JSON字符串是数组。所以如果你检查IsObject()它失败了。仔细看一下JSON字符串，你会发现你在乎的是[]，它表明它是一个数组。从JSON官方网站

采取：

的阵列开始于[（左括号）和结尾（右括号）。 值由（逗号）分隔。

试试下面的代码：

string str_json = "[{\"Node\":\"9478149a08f9\",\"Address\":\"172.17.0.2\",\"ServiceID\":\"HSS\",\"ServiceName\":\"HSS\",\"ServiceTags\":[],\"ServiceAddress\":\"\",\"ServicePort\":6666,\"ServiceEnableTagOverride\":false,\"CreateIndex\":2855,\"ModifyIndex\":2855}]"; 
rapidjson::Document doc; 
doc.Parse(str_json.c_str()); 

//assert(doc.IsObject()); 
if(doc.IsArray()){ 
    cout << "is array" << endl; 
} 
for(Value::ConstValueIterator itr = doc.Begin(); itr != doc.End(); ++itr){ 
    const Value& obj = *itr; 
    for(Value::ConstMemberIterator it = obj.MemberBegin(); it != obj.MemberEnd(); ++it){ 
     if(it->value.IsString()){ 
      cout << it->name.GetString() << ": " << it->value.GetString() << endl; 
     } 
     // other codes... 
    } 
}