Correct usage of Poco C++ JSON for parsing data

EDIT: as of 1.5.2, things were simplified by making DefaultHandler, well ... default (and renaming it to its proper name - ParseHandler. So, if all you need is parsing, no need to explicitly provide the handler anymore:

// objectsstd::string json = "{ \"test\" : { \"property\" : \"value\" } }";Parser parser;Var result = parser.parse(json);Object::Ptr object = result.extract<Object::Ptr>();Var test = object->get("test");object = test.extract<Object::Ptr>();test = object->get("property");std::string value = test.convert<std::string>();// array of objectsstd::string json = "[ {\"test\" : 0}, { \"test1\" : [1, 2, 3], \"test2\" : 4 } ]";Parser parser;Var result = parser.parse(json);Array::Ptr arr = result.extract<Array::Ptr>();Object::Ptr object = arr->getObject(0);//assert (object->getValue<int>("test") == 0);object = arr->getObject(1);arr = object->getArray("test1");result = arr->get(0);assert (result == 1);

See this answer for more details.

#include <iostream>#include <string>#include <Poco/JSON/JSON.h>#include <Poco/JSON/Parser.h>#include <Poco/Dynamic/Var.h>using namespace std;using namespace Poco::JSON;string GetValue(Object::Ptr aoJsonObject, const char *aszKey) {    Poco::Dynamic::Var loVariable;    string lsReturn;    string lsKey(aszKey);    // Get the member Variable    //    loVariable = aoJsonObject->get(lsKey);    // Get the Value from the Variable    //    lsReturn = loVariable.convert<std::string>();    return lsReturn;}int main(int argc, char *argv[]) {    string lsJson;    Parser loParser;    lsJson = "{\"TransactionCode\":\"000000\",\"FileRecordSequenceNumber\":\"111111\",\"TcrSequenceNumber\":\"222222\",\"TransactionRouteIndicator\":\"ABCDE\",\"MerchantEstablishmentNumber\":\"00000000000\",\"MerchantName\":\"BBBBBBBBB\",\"MerchantCity\":\"CCCCCCCC\"}";    cout << lsJson << endl;    // Parse the JSON and get the Results    //    Poco::Dynamic::Var loParsedJson = loParser.parse(lsJson);    Poco::Dynamic::Var loParsedJsonResult = loParser.result();    // Get the JSON Object    //    Object::Ptr loJsonObject = loParsedJsonResult.extract<Object::Ptr>();    // Get the values for the member variables    //    //    cout << "TransactionCode             " << GetValue(loJsonObject, "TransactionCode")               << endl;    cout << "FileRecordSequenceNumber    " << GetValue(loJsonObject, "FileRecordSequenceNumber")      << endl;    cout << "TcrSequenceNumber           " << GetValue(loJsonObject, "TcrSequenceNumber")             << endl;    cout << "TransactionRouteIndicator   " << GetValue(loJsonObject, "TransactionRouteIndicator")     << endl;    cout << "MerchantEstablishmentNumber " << GetValue(loJsonObject, "MerchantEstablishmentNumber")   << endl;    cout << "MerchantName                " << GetValue(loJsonObject, "MerchantName")                  << endl;    cout << "MerchantCity                " << GetValue(loJsonObject, "MerchantCity")                  << endl;    return 0;}Results:{"TransactionCode":"000000","FileRecordSequenceNumber":"111111","TcrSequenceNumber":"222222","TransactionRouteIndicator":"ABCDE","MerchantEstablishmentNumber":"00000000000","MerchantName":"BBBBBBBBB","MerchantCity":"CCCCCCCC"}TransactionCode             000000FileRecordSequenceNumber    111111TcrSequenceNumber           222222TransactionRouteIndicator   ABCDEMerchantEstablishmentNumber 00000000000MerchantName                BBBBBBBBBMerchantCity                CCCCCCCC