Deserialize a json array to objects using Jackson and WebClient

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>>() {})

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.

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

{
  "accountOrders": [
    {

But, your JSON is

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

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

bodyToMono(AccountOrder[].class)