Pact Test function failed with an exception, possibly due to Mismatches

Question

I am new to Pact contract testing. It seems like pact consumer test is failing with following error.

Initially it passed if I put try/catch around api call but when I removed it , I received exception regarding HtmlMessageConverter as response extractor couldn't extract response, I set header as (application/json & application/octate-stream). Now after accepting that header I am getting following pact exception.

What I am doing wrong here?

Pact Test function failed with an exception, possibly due to Mismatches(mismatches=[PartialMismatch(mismatches=[BodyMismatch(expected=Map(OrderHeaderId -> ORD-001, ExternalOrderId -> 22194528), actual={"OrderHeaderId":"ORD-001","ExternalOrderId":"22194528"}, mismatch=Type mismatch: Expected Map Map(OrderHeaderId -> ORD-001, ExternalOrderId -> 22194528) but received String '{"OrderHeaderId":"ORD-001","ExternalOrderId":"22194528"}', path=$, diff=-{
-    "OrderHeaderId": "ORD-001",
-    "ExternalOrderId": "22194528"
-}
+"{\"OrderHeaderId\":\"ORD-001\",\"ExternalOrderId\":\"22194528\"}")])])

        String inputJson =
                "{\n" + "  \"OrderHeaderId\":\"ORD-001\",\n" + "  \"ExternalOrderId\": \"22194528\"\n" + "} ";

        return builder
            .given("order-created")
            .uponReceiving("a request to create order")
            .path(restOrderCreatePath)
            .method("POST")
            .headers(headers)
            .body(inputJson)
            .willRespondWith()
            .status(200)
            .body(jsonBody)
            .toPact();

      @Test
      @PactVerification(fragment = "createOrderPactWithRibbon")
      public void verifycreateOrderPactWithRibbon() throws Exception {


          Document document = new Document();
          document.put("OrderHeaderId","ORD-001");
          document.put("ExternalOrderId","22194528");

          // try {
          ResponseEntity<RestApiResponse<Document>> response =
              restApiService.processPostRequest(
                      document, restOrderComponentUrl, restOrderCreatePath);


         Assert.assertTrue("No data received in response.", !(response == null));
         /* } catch (Exception ignored) {
            ignored.printStackTrace();
         }*/
      }