Deserialize a json array to objects using Jackson and WebClient

Question

I have a problem during the deserialization of a json array using Spring. I have this json response from a service:

[
    {
        \"symbol\": \"XRPETH\",
          


        

Answer 1

Your response is simply List<AccountOrder>. But, your POJO has wrapped List<AccountOrder>. So, according to your POJO, your JSON should be

{
  "accountOrders": [
    {

But, you are JSON is

[
    {
       "symbol": "XRPETH",
       "orderId": 12122,
        ....

So, there is mismatch and failing the deserialization. You need to change to

bodyToMono(AccountOrder[].class)

Answer 2

Regarding your updated answer to your question, using bodyToFlux is unnecessarily inefficient and semantically doesn't make much sense either as you don't really want a stream of orders. What you want is simply to be able to parse the response as a list.

bodyToMono(List<AccountOrder>.class) won't work due to type erasure. You need to be able to retain the type at runtime, and Spring provides ParameterizedTypeReference for that:

bodyToMono(new ParameterizedTypeReference<List<AccountOrder>>() {})

Answer 3

For the response to be matched with AccountOrderList class, json has to be like this

{
  "accountOrders": [
    {
        "symbol": "XRPETH",
        "orderId": 12122,
        "clientOrderId": "xxx",
        "price": "0.00000000",
        "origQty": "25.00000000",
        "executedQty": "25.00000000",
        "status": "FILLED",
        "timeInForce": "GTC",
        "type": "MARKET",
        "side": "BUY",
        "stopPrice": "0.00000000",
        "icebergQty": "0.00000000",
        "time": 1514558190255,
        "isWorking": true
    },
    {
        "symbol": "XRPETH",
        "orderId": 1212,
        "clientOrderId": "xxx",
        "price": "0.00280000",
        "origQty": "24.00000000",
        "executedQty": "24.00000000",
        "status": "FILLED",
        "timeInForce": "GTC",
        "type": "LIMIT",
        "side": "SELL",
        "stopPrice": "0.00000000",
        "icebergQty": "0.00000000",
        "time": 1514640491287,
        "isWorking": true
    },
    ....
]
}

This is what the error message says "out of START_ARRAY token"

If you cannot change the response, then change your code to accept Array like this

this.webClient.get().uri(payload).accept(MediaType.APPLICATION_JSON)
                        .retrieve().bodyToMono(AccountOrder[].class).log();

You can convert this array to List and then return.