arduino/libraries/ArduinoJson/examples/JsonHttpClient/JsonHttpClient.ino
2018-11-03 20:21:33 +00:00

103 lines
2.5 KiB
C++

// ArduinoJson - arduinojson.org
// Copyright Benoit Blanchon 2014-2018
// MIT License
//
// This example shows how to parse a JSON document in an HTTP response.
// It uses the Ethernet library, but can be easily adapted for Wifi.
//
// It performs a GET resquest on arduinojson.org/example.json
// Here is the expected response:
// {
// "sensor": "gps",
// "time": 1351824120,
// "data": [
// 48.756080,
// 2.302038
// ]
// }
#include <ArduinoJson.h>
#include <Ethernet.h>
#include <SPI.h>
void setup() {
// Initialize Serial port
Serial.begin(9600);
while (!Serial) continue;
// Initialize Ethernet library
byte mac[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};
if (!Ethernet.begin(mac)) {
Serial.println(F("Failed to configure Ethernet"));
return;
}
delay(1000);
Serial.println(F("Connecting..."));
// Connect to HTTP server
EthernetClient client;
client.setTimeout(10000);
if (!client.connect("arduinojson.org", 80)) {
Serial.println(F("Connection failed"));
return;
}
Serial.println(F("Connected!"));
// Send HTTP request
client.println(F("GET /example.json HTTP/1.0"));
client.println(F("Host: arduinojson.org"));
client.println(F("Connection: close"));
if (client.println() == 0) {
Serial.println(F("Failed to send request"));
return;
}
// Check HTTP status
char status[32] = {0};
client.readBytesUntil('\r', status, sizeof(status));
if (strcmp(status, "HTTP/1.1 200 OK") != 0) {
Serial.print(F("Unexpected response: "));
Serial.println(status);
return;
}
// Skip HTTP headers
char endOfHeaders[] = "\r\n\r\n";
if (!client.find(endOfHeaders)) {
Serial.println(F("Invalid response"));
return;
}
// Allocate the JSON document
// Use arduinojson.org/assistant to compute the capacity.
const size_t capacity = JSON_OBJECT_SIZE(3) + JSON_ARRAY_SIZE(2) + 60;
DynamicJsonDocument doc(capacity);
// Parse JSON object
DeserializationError error = deserializeJson(doc, client);
if (error) {
Serial.print(F("deserializeJson() failed: "));
Serial.println(error.c_str());
return;
}
// Extract values
JsonObject root = doc.as<JsonObject>();
Serial.println(F("Response:"));
Serial.println(root["sensor"].as<char*>());
Serial.println(root["time"].as<char*>());
Serial.println(root["data"][0].as<char*>());
Serial.println(root["data"][1].as<char*>());
// Disconnect
client.stop();
}
void loop() {
// not used in this example
}
// Visit https://arduinojson.org/v6/example/http-client/ for more.