How to add a JSON object to the body of an HTTP POST request

Bruno L

Hello,

I am using Java 8 ME Embedded and I would like to add a Json object in the body of an http request.

I would like to do something like :

-----------------------------------------------------------------------------------------

     HttpClientBuilder clientBuilder = HttpClientBuilder.getInstance();

        HttpClient client = clientBuilder.build();

        HttpRequestBuilder requestBuilder = client.build("my_URI");
        requestBuilder.setHeader(HttpHeader.ACCEPT, "text/plain");

[...]

        requestBuilder.setMethod(HttpMethod.POST);

        HttpRequest request = requestBuilder.build();

//creating the Json object to be sent in the http request body
      JsonObject myJsonObj= Json.createObjectBuilder()
     .add("firstname", "John")
     .add("lastname", "XXX")
     .build();

//This part, I am a bit confused : how to get the OutputStream in which I should put the Json object?

JsonWriter jsonWriter = Json.createWriter(java.io.OutputStream out);

jsonWriter.writeObject(myJsonObj);

jsonWriter.close();

     //invoking the http request

      HttpResponse response = request.invoke();

-----------------------------------------------------------------------------------------

Do you have any tip, please ?
Thanks in advance.

Bruno

Sergey.N-Oracle

You have to create class for this interface

Sergey.N-Oracle

Hi Bruno,

please take a look at HttpRequestBuilder.setBody

/Sergey

Bruno L

Hi Sergey,

I did but I am still confused : I need a StreamedMessageBody interface. How do I get it?
Bruno

Sergey.N-Oracle

You have to create class for this interface

Bruno L

Thanks  a lot Sergey, once again !

What I did (for other people that might have the same need) :

----------------------------------------------------------------------------------------

Create the class implementing the StreamedMessageBody interface

----------------------------------------------------------------------------------------

public class MessageBody implements StreamedMessageBody  {
   
    @Override
    public void write(HttpMessageHeaders headers, java.io.OutputStream bodyStream) {
   
      System.out.println("in write method");
       
      JsonObject jsonObject = Json.createObjectBuilder()
     .add("firstname", "John")
     .add("lastName", "Smith")      
     .build();
             
      JsonWriter jsonWriter=Json.createWriter(bodyStream);
      jsonWriter.writeObject(jsonObject);
      jsonWriter.close();

}

----------------------------------------------------------------------------------------

Then, in my main class :

----------------------------------------------------------------------------------------

       private void sendJsonHttpRequest(){
       // default client builder
        HttpClientBuilder clientBuilder = HttpClientBuilder.getInstance();

        HttpClient client = clientBuilder.build();

        HttpRequestBuilder requestBuilder = client.build("http://myURI");
        requestBuilder.setHeader(HttpHeader.ACCEPT, "text/plain");
        requestBuilder.setHeader(HttpHeader.CONTENT_TYPE, "application/json");

        requestBuilder.setMethod(HttpMethod.PUT);
       
//Get the StreamedMessageBody interface
        StreamedMessageBody messageBody= new MessageBody();

//Update the requestBuilder
        requestBuilder.setBody(messageBody);

        // prepared client request is ready for execution
        HttpRequest request = requestBuilder.build();

        System.out.println("URI=" + request.getURI());

        HttpMessageHeaders httpMessageHeaders = request.getHeaders();

//Invoke the request
        HttpResponse response = request.invoke();

    }