Post XML to Microservice-Arduino Uno Wifi rev.2

Projects Networking, Protocols, and Devices
1

Good morning,

I have an image of a microservice running in the docker accessible via http://localhost:8080/.

Essentially, this microservice has an engine where it is possible to run BPMN workflow files which are made in the Eclipse IDE.

On the other hand, this microservice also contains a REST service in which it is possible to send an XML description to interact with the Engine.

So, through the Windows 10 powersheell, I can send the following CURL command to the Engine:

curl.exe --user admin:adminadmin -H "Content-Type: application/xml" -H 'Accept: application/xml' -d  '<document xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xs=\"http://www.w3.org/2001/XMLSchema\">
<item name=\"$modelversion\"><value xsi:type=\"xs:string\">1.0.0</value></item>
<item name=\"$taskid\"><value xsi:type=\"xs:int\">1000</value></item>
<item name=\"$eventid\"><value xsi:type=\"xs:int\">10</value></item>
<item name=\"_budget\"><value xsi:type=\"xs:int\">150</value></item>
</document>' http://localhost:8080/api/workflow/workitem

Getting the following response from the Engine:

>> </document>' http://192.168.1.65:8080/api/workflow/workitem --user admin:adminadmin
<?xml version="1.0" encoding="UTF-8" standalone="yes"?><data xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xs="http://www.w3.org/2001/XMLSchema"><document><item name="$created"><value xsi:type="xs:dateTime">2021-07-03T13:42:17.037+02:00</value></item><item name="$creator"><value xsi:type="xs:string">admin</value></item><item name="$editor"><value xsi:type="xs:string">admin</value></item><item name="$eventid"><value xsi:type="xs:int">0</value></item><item name="$eventlog"><value xsi:type="xs:string">2021-07-03T13:42:17.018|1.0.0|1000.10|1000|</value></item><item name="$isauthor"><value xsi:type="xs:boolean">true</value></item><item name="$lastevent"><value xsi:type="xs:int">10</value></item><item name="$lasteventdate"><value xsi:type="xs:dateTime">2021-07-03T13:42:16.987+02:00</value></item><item name="$lasttask"><value xsi:type="xs:int">1000</value></item><item name="$modelversion"><value xsi:type="xs:string">1.0.0</value></item><item name="$modified"><value xsi:type="xs:dateTime">2021-07-03T13:42:17.037+02:00</value></item><item name="$participants"><value xsi:type="xs:string">admin</value></item><item name="$processid"><value xsi:type="xs:int">1600</value></item><item name="$taskid"><value xsi:type="xs:int">1600</value></item><item name="$transactionid"><value xsi:type="xs:string">52bc23820da0f9ee</value></item><item name="$uniqueid"><value xsi:type="xs:string">701eed86-e627-4b73-bc95-a217c9ea6bd6</value></item><item name="$workflowgroup"><value xsi:type="xs:string">Simple</value></item><item name="$workflowstatus"><value xsi:type="xs:string">Task 7</value></item><item name="$workitemid"><value xsi:type="xs:string">d132ec54-0142-47e1-a0c2-a541662741f9</value></item><item name="_budget"><value xsi:type="xs:int">150</value></item><item name="namcreator"><value xsi:type="xs:string">admin</value></item><item name="namcurrenteditor"><value xsi:type="xs:string">admin</value></item><item name="numlastactivityid"><value xsi:type="xs:int">10</value></item><item name="txtworkflowgroup"><value xsi:type="xs:string">Simple</value></item><item name="txtworkflowstatus"><value xsi:type="xs:string">Task 7</value></item><item name="type"><value xsi:type="xs:string">workitem</value></item></document></data>

Confirming the successful sending of the xml message, through the curl command.

I have an Arduino Uno Wifi Rev.2 and I'm having trouble trying to send this XML description to the Engine.

Essentially, I searched here on this forum as well as on Google and made the following code, however without success:

#include <WiFiNINA.h>
#include <ArduinoHttpClient.h>

char ssid[] = "#"; //  your network SSID (name)
char pass[] = "Qm5TYs$%123GHYd5)#-_|/M-]<>!;,[+.:/-&I=Ghio95nh)9aWn%#}(9]?*";

int port = 8080;
const char serverAddress[] = "http://192.168.1.65";  // server name

WiFiClient wifi;
HttpClient client = HttpClient(wifi, serverAddress, port);

int status = WL_IDLE_STATUS;

void setup() {
  Serial.begin(9600);
   while (status != WL_CONNECTED) {
    Serial.print("Attempting to connect to WPA SSID: ");
    Serial.println(ssid);
    status = WiFi.begin(ssid, pass); 
    delay(5000);
  }
  Serial.print("SSID: ");
  Serial.println(WiFi.SSID());
  IPAddress ip = WiFi.localIP();
  IPAddress gateway = WiFi.gatewayIP();
  Serial.print("IP Address: ");
  Serial.println(ip);
}

void loop() {

  client.connectionKeepAlive();
  Serial.println("making POST request");
  String postData = "<document xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xs=\"http://www.w3.org/2001/XMLSchema\"><item name=\"$modelversion\"><value xsi:type=\"xs:string\">1.0.0</value></item><item name=\"$taskid\"><value xsi:type=\"xs:int\">1000</value></item><item name=\"$eventid\"><value xsi:type=\"xs:int\">10</value></item><item name=\"_budget\"><value xsi:type=\"xs:int\">150</value></item></document>";
  Serial.print("Post Data Length: ");
  Serial.println(postData.length());

  client.beginRequest();
  client.post("/api/workflow/workitem");
  client.sendHeader("--user admin:adminadmin");
  client.sendHeader("Content-Type", "application/xml");
  client.sendHeader("Accept", "application/xml");
  
  
  
  client.endRequest();
  client.println(postData);

   while (client.connected()) {       // while connected to the server,
    if (client.available()) {        // if there is a response from the server,
      String result = client.readString();  // read it
      Serial.print(result);               // and print it
    }
  }
   

  // read the status code and body of the response
  int statusCode = client.responseStatusCode();
  String response = client.responseBody();

  Serial.print("Status code: ");
  Serial.println(statusCode);
  Serial.print("Response: ");
  Serial.println(response);

  Serial.println("Wait five seconds");
  delay(5000);
}

If I run the code in Arduino, I'm faced with the following output:

imagem
imagem1326×459 13.7 KB

Essentially what's happening is that I'm not getting any response from the microservice. I honestly don't really understand what I might be doing wrong.

Thanks You,

Best regards

2

Does this thread help? HTTP status code "-3" - Using Arduino / Project Guidance - Arduino Forum

3

Thank you,
This Thread gave me some "lights":

First of all it is necessary to remove the "http" before the local address. On the other hand, I was also doing wrong in the body section, in other words "client.post(postData)" should be placed between "client.beginBody();" and the "client.endRequest();".

The final code is as follows:

#include <WiFiNINA.h>
#include <ArduinoHttpClient.h>

char ssid[] = "#"; //  your network SSID (name)
char pass[] = "Qm5TYs$%123GHYd5)#-_|/M-]<>!;,[+.:/-&I=Ghio95nh)9aWn%#}(9]?*";

int port = 8080;
const char serverAddress[] = "192.168.1.65";  // server name
char buf[200];

WiFiClient wifi;
HttpClient client = HttpClient(wifi, serverAddress, port);

int status = WL_IDLE_STATUS;

void setup() {
  Serial.begin(9600);
   while (status != WL_CONNECTED) {
    Serial.print("Attempting to connect to WPA SSID: ");
    Serial.println(ssid);
    status = WiFi.begin(ssid, pass); 
    delay(5000);
  }
  Serial.print("SSID: ");
  Serial.println(WiFi.SSID());
  IPAddress ip = WiFi.localIP();
  IPAddress gateway = WiFi.gatewayIP();
  Serial.print("IP Address: ");
  Serial.println(ip);
}

void loop() {

  client.connectionKeepAlive();
  Serial.println("making POST request");  
  String postData = "<document xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xs=\"http://www.w3.org/2001/XMLSchema\"><item name=\"$modelversion\"><value xsi:type=\"xs:string\">1.0.0</value></item><item name=\"$taskid\"><value xsi:type=\"xs:int\">1000</value></item><item name=\"$eventid\"><value xsi:type=\"xs:int\">10</value></item><item name=\"_budget\"><value xsi:type=\"xs:int\">150</value></item></document>";
  
  Serial.print("Post Data Length: ");
  Serial.println(postData.length());
  //Serial.print(postData);

  client.beginRequest();
  client.post("/api/workflow/workitem");  
  client.sendBasicAuth("admin","adminadmin");
  client.sendHeader("Content-Type", "application/xml");
  client.sendHeader("Accept", "application/xml");
  
  client.beginBody();
  
  client.post(postData);
  client.endRequest();
  

   while (client.connected()) {       // while connected to the server,
    if (client.available()) {        // if there is a response from the server,
      String result = client.readString();  // read it
      Serial.print(result);               // and print it
    }
  }
   

 /* // read the status code and body of the response
  int statusCode = client.responseStatusCode();
  String response = client.responseBody();

  Serial.print("Status code: ");
  Serial.println(statusCode);
  Serial.print("Response: ");
  Serial.println(response);*/

  Serial.println("Wait five seconds");
  delay(5000);
}

Unfortunately, at this moment I am faced with another error:

"javax.xml.bind.UnmarshalException

  • with linked exception:
    [org.xml.sax.SAXParseException; Premature end of file.]"

imagem
imagem834×440 10.9 KB

What's confusing me here is that the curl command works correctly.

4

I am not familiar enough with xml to be properly able to help. Since the error message is premature end of file, could it be as simple as a missing EOL such as \n on the postData?

5

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