使用 Jackson 和 WebClient 将 json 数组反序列化为对象

我在使用Spring反序列化json数组期间遇到问题。我有来自服务的这个json响应:

[
    {
        "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
    },
    ....
]

我使用Spring WebFlux中的新WebClient获得这个json,代码如下:

@Override
    public Mono<AccountOrderList> getAccountOrders(String symbol) {
        return binanceServerTimeApi.getServerTime().flatMap(serverTime -> {
            String apiEndpoint = "/api/v3/allOrders?";
            String queryParams = "symbol=" +symbol.toUpperCase() + "&timestamp=" + serverTime.getServerTime();
            String signature = HmacSHA256Signer.sign(queryParams, secret);
            String payload = apiEndpoint + queryParams + "&signature="+signature;
            log.info("final endpoint:"+ payload);
            return this.webClient
                    .get()
                    .uri(payload)
                    .accept(MediaType.APPLICATION_JSON)
                    .retrieve()
                    .bodyToMono(AccountOrderList.class)
                    .log();
        });
    }

帐户订单列表

public class AccountOrderList {

    private List<AccountOrder> accountOrders;

    public AccountOrderList() {
    }

    public AccountOrderList(List<AccountOrder> accountOrders) {
        this.accountOrders = accountOrders;
    }

    public List<AccountOrder> getAccountOrders() {
        return accountOrders;
    }

    public void setAccountOrders(List<AccountOrder> accountOrders) {
        this.accountOrders = accountOrders;
    }
}

AccountOrder是一个简单的pojo,用于映射字段。

实际上,当我点击一个get时,它说:

org.springframework.core.codec.DecodingException: JSON decoding error: Cannot deserialize instance of `io.justin.demoreactive.domain.AccountOrder` out of START_ARRAY token; nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize instance of `io.justin.demoreactive.domain.AccountOrder` out of START_ARRAY token
 at [Source: UNKNOWN; line: -1, column: -1]

如何使用新的 webflux 模块正确反序列化 json?我做错了什么?

更新 05/02/2018

两个答案都是正确的。他们完美地解决了我的问题,但最终我决定使用稍微不同的方法:

@Override
    public Mono<List<AccountOrder>> getAccountOrders(String symbol) {
        return binanceServerTimeApi.getServerTime().flatMap(serverTime -> {
            String apiEndpoint = "/api/v3/allOrders?";
            String queryParams = "symbol=" +symbol.toUpperCase() + "&timestamp=" + serverTime.getServerTime();
            String signature = HmacSHA256Signer.sign(queryParams, secret);
            String payload = apiEndpoint + queryParams + "&signature="+signature;
            log.info("final endpoint:"+ payload);
            return this.webClient
                    .get()
                    .uri(payload)
                    .accept(MediaType.APPLICATION_JSON)
                    .retrieve()
                    .bodyToFlux(AccountOrder.class)
                    .collectList()
                    .log();
        });
    }

另一种方法是直接返回A Flux,这样您就不必将其转换为列表。(这就是通量:n个元素的集合)。


答案 1

关于您更新的问题答案,使用是不必要的低效,并且在语义上也没有多大意义,因为您并不真正想要订单流。您想要的只是能够将响应解析为列表。bodyToFlux

bodyToMono(List<AccountOrder>.class)由于类型擦除,将不起作用。您需要能够在运行时保留该类型,而Spring提供了:ParameterizedTypeReference

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

答案 2

要使响应与类匹配,json 必须如下所示AccountOrderList

{
  "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
    },
    ....
]
}

这就是错误消息所说的“超出START_ARRAY令牌”的内容"

如果无法更改响应,请更改代码以接受数组,如下所示

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

您可以将此数组转换为 List,然后返回。


推荐