Question

我目前正在构建一个使用RestTemplate构建对Alpha Vantage API的API请求的应用程序。以下是排除不必要元数据的示例响应：

{
  "Time Series (Daily)": {
    "2017-11-10": {
      "1. open": "83.7900",
      "2. high": "84.1000",
      "3. low": "83.2300",
      "4. close": "83.8700",
      "5. volume": "19340435"
    },
    "2017-11-09": {
      "1. open": "84.1100",
      "2. high": "84.2700",
      "3. low": "82.9000",
      "4. close": "84.0900",
      "5. volume": "20924172"
    },
    "2017-11-08": {
      "1. open": "84.1400",
      "2. high": "84.6100",
      "3. low": "83.8300",
      "4. close": "84.5600",
      "5. volume": "18034170"
    },
    "2017-11-07": {
      "1. open": "84.7700",
      "2. high": "84.9000",
      "3. low": "83.9300",
      "4. close": "84.2700",
      "5. volume": "17152583"
    },
    "2017-11-06": {
      "1. open": "84.2000",
      "2. high": "84.7000",
      "3. low": "84.0800",
      "4. close": "84.4700",
      "5. volume": "19039847"
    },
    "2017-11-03": {
      "1. open": "84.0800",
      "2. high": "84.5400",
      "3. low": "83.4000",
      "4. close": "84.1400",
      "5. volume": "17569120"
    }
  }
}

我正在构建我的数据传输对象层，它包含在内：

顶层：

public class Stock extends Dto{

    @JsonProperty("Time Series (Daily)")
    private TimeSeries timeSeries;

    public TimeSeries getTimeSeries() {
        return timeSeries;
    }

    public void setTimeSeries(TimeSeries timeSeries) {
        this.timeSeries = timeSeries;
    }
}

中间层：

public class TimeSeries extends Dto{

    private List<Day> days;

    public List<Day> getDays() {
        return days;
    }

    public void setDays(List<Day> days) {
        this.days = days;
    }
}

最终层（数据平移）：

@JsonIgnoreProperties(ignoreUnknown = true)
public class Day extends Dto{

    @JsonProperty("1. open")
    private double open;

    @JsonProperty("2. high")
    private double high;

    @JsonProperty("3. low")
    private double low;

    @JsonProperty("4. close")
    private double close;

    @JsonProperty("5. volume")
    private double volume;

    public double getOpen() {
        return open;
    }

    public void setOpen(double open) {
        this.open = open;
    }

    public double getHigh() {
        return high;
    }

    public void setHigh(double high) {
        this.high = high;
    }

    public double getLow() {
        return low;
    }

    public void setLow(double low) {
        this.low = low;
    }

    public double getClose() {
        return close;
    }

    public void setClose(double close) {
        this.close = close;
    }

    public double getVolume() {
        return volume;
    }

    public void setVolume(double volume) {
        this.volume = volume;
    }
}

运行我的应用程序时会发生什么： 当我运行应用程序时，顶层（Stock.java）会填充一个Time Series对象，但是下一层（TimeSeries.java）不包含我期望的（Day.java）对象数组，它是null。我试过了：

@JSONProperty("2017-11-10") 
private Day day;

这确实有效，并弥补了中间层与最后一层之间的差距，数据很好......但这不是我所追求的。

我希望发生/想要发生的事情： 我想在日期列表中获取所有日期（在TimeSeries.java中）的数组，但它不会工作，我相信这是因为JSON响应不能将它们作为数组提供JavaScript对象，而不是实际的键和对，所以我不能只列出它们，但必须直接深入到最终对象......这不是我想要的。

我已阅读过有关此主题的主题

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如果有人知道如何让中间步骤工作并将对象实际存储在密钥＆＃34;时间序列（每日）＆＃34;然后，几天就可以访问他们非常棒的价值。

注意：此外，如果您要对此进行投票，请在下面说明您为什么这样做。我在过去的5个小时里对此进行了研究，所以我相信我已经做了尽职调查，可以在这里问我，并且我已经尽可能彻底了...... c＆＃39; mon。

Answer 1

你的json中没有Json数组。实际上你有json对象有多个字段，所以你的java数据结构应该用Map表示而不是List。如果你想保持当前的类结构，那么你应该明白，你丢失了时间序列的日期部分。我不认为你想要这个。

选项1.使用HashMap<String, Day> timeSeries

public class Stock {

    @JsonProperty("Time Series (Daily)")
    private HashMap<String, Day> timeSeries;

    public HashMap<String, Day> getTimeSeries() {
        return timeSeries;
    }

    public void setTimeSeries(HashMap<String, Day> timeSeries) {
        this.timeSeries = timeSeries;
    }
}

选项2.更改TimeSeries代码

public class TimeSeries {

    // TreeMap because it preserves sorting order
    @JsonIgnore
    private Map<String, Day> days = new TreeMap<>();

    @JsonAnySetter
    public void setDays(String time, Day value){
        days.put(time,value);
    }

    @JsonAnyGetter
    public Map<String, Day> getData() {
        return days;
    }

    // add getDays() if you need only values
    // and if you need list, can use new ArrayList(days.values()) 
    @JsonIgnore
    public Collection<Day> getDays(){
        return days.values();
    }
}

如何在SpringBoot中使用Jackson将JSON对象数组解析为DTO

1 个答案: