Question

如何将以下JSON转换为Java HashMap 什么是POJO 如何用Jackson映射JSON对象

*{
    "Meta Data": {
        "1. Information": "Daily Prices (open, high, low, close) and Volumes",
        "2. Symbol": "IBM",
        "3. Last Refreshed": "2020-08-14",
        "4. Output Size": "Compact",
        "5. Time Zone": "US/Eastern"
    },
    "Time Series (Daily)": {
        "2020-08-14": {
            "1. open": "124.2000",
            "2. high": "125.5600",
            "3. low": "123.9100",
            "4. close": "125.2700",
            "5. volume": "2963753"
        },
        "2020-08-13": {
            "1. open": "125.9600",
            "2. high": "126.3900",
            "3. low": "124.7700",
            "4. close": "125.0300",
            "5. volume": "3171258"
        }
    }
}

这是Alphavantage的POJO：

public class Alphavantage {
    public MetaData metaData;
    public TimeSeriesDaily timeSeriesDaily;
}

这是MetaData的POJO：

public class MetaData{
    public String _1Information;
    public String _2Symbol;
    public String _3LastRefreshed;
    public String _4OutputSize;
    public String _5TimeZone;
}

TimeSeriesDaily的Pojo：

public class TimeSeriesDaily {
    public _20200814 _20200814;
}

这试图使用Java Jackson映射Pojo：

public static Map<Alphavantage,Map<TimeSeriesDaily,Object>> getAlphaData() {        
        RestAssured.baseURI = uri;
        RequestSpecification request = RestAssured.given().log().all();
        Response response = request.get(uri + "/query?function=TIME_SERIES_DAILY&symbol=IBM&apikey=demo");
        String jsonResponse=response.getBody().asString();

        ObjectMapper mapper = new ObjectMapper();
        Map<Alphavantage,Map<TimeSeriesDaily,Object>> data = mapper.readValue(jsonResponse, new TypeReference<Map<Alphavantage,Map<TimeSeriesDaily,Object>>>(){});
        return data;
    }

Answer 1

要使其正常工作，Java对象需要与JSON字段键具有完全相同的名称。

因此，杰克逊将无法将1. Information映射到_1Information。您需要使用以下内容：

@JsonProperty("1. Information")
public String _1Information;

其他所有字段都一样。

将JSON（反序列化）转换为Java POJO Jackson

1 个答案: