Java – pass JSON to webservice

I developed a web service in Java using the dropwizard framework I hope it consumes a JSON

My service code is –

– resource level

@Path(value = "/product")
  public class ProductResource{ 

   @POST
   @Path(value = "/getProduct")
   @Consumes(MediaType.APPLICATION_JSON)
   @Produces(MediaType.APPLICATION_JSON)
   public Product getProduct(InputBean bean) {
    // Just trying to print the parameters. 
    System.out.println(bean.getProductId());
    return new Product(1,"Product1-UpdatedValue",1,1);
   }
}

Inputbean is a simple bean class

public class InputBean {

    private int productId;
    private String productName;

    public String getProductName() {
        return productName;
    }
    public void setProductName(String productName) {
        this.productName= productName;
    }

    public int getProductId() {
        return productId;
    }
    public void setProductId(int productId) {
        this.productId= productId;
        }
}

Customer code –

public String getProduct() {

            Client client = Client.create();
            WebResource webResource = client.resource("http://localhost:8080/product/getProduct");
JSONObject data = new JSONObject ("{\"productId\": 1,\"productName\": \"Product1\"}");
            ClientResponse response = webResource.type(MediaType.APPLICATION_JSON)
                    .accept(MediaType.APPLICATION_JSON)
                    .post(ClientResponse.class,data);
            return response.getEntity(String.class);
        }

I received an error –

ClientHandlerException

Is there anything wrong with this code?

JSONObject data = new JSONObject ("{\"productId\": 1,\"productName\": \"Product1\"}");
ClientResponse response =  webResource.type(MediaType.APPLICATION_JSON)
                        .accept(MediaType.APPLICATION_JSON)
                        .post(ClientResponse.class,data);

Can anyone point out what I might be missing?

Customer log –

Solution

You set the type correctly and make the request correctly

The problem is that you can't handle the response

A message body reader for Java class my.class.path.InputBean

... basically, what you want to return is that you can't read, format and enter anything useful

You returned a product type in the service, which is your octet stream, but I don't see where you output messagebodywriter to JSON

You need:

@Provider
@Produces( { MediaType.APPLICATION_JSON } )
public static class ProductWriter implements MessageBodyWriter<Product>
{
    @Override
    public long getSize(Product data,Class<?> type,Type genericType,Annotation annotations[],MediaType mediaType)
    {
        // cannot predetermine this so return -1
        return -1;
    }

    @Override
    public boolean isWriteable(Class<?> type,Annotation[] annotations,MediaType mediaType)
    {
        if ( mediaType.equals(MediaType.APPLICATION_JSON_TYPE) )
        {
            return Product.class.isAssignableFrom(type);
        }

        return false;
    }

    @Override
    public void writeTo(Product data,MediaType mediaType,MultivaluedMap<String,Object> headers,OutputStream out) throws IOException,WebApplicationException
    {
        if ( mediaType.equals(MediaType.APPLICATION_JSON_TYPE) )
        {
            outputToJSON( data,out );
        }
    }
    private void outputToJSON(Product data,OutputStream out) throws IOException
    {
        try (Writer w = new OutputStreamWriter(out,"UTF-8"))
        {
            gson.toJson( data,w );
        }
    }
}