Parse json string using jaxson root value customization

问题

I have a huge JSON string as a response to a rest call. Part of the response has the following structure. I am using com.fasterxml.jackson

“historicalData”: {
     “1585573790000”: {“score”:23.54, “count”:3},
     “1585487390000”: {“score”:12.65, “count”:2}
    },
//1585573790000 -> being the epoch time

The model I thought of so far is ArrayList of

private class HistoricalData {
        Long epochTime;
        Double score;
        Longcount;

    }

But I am unable to map the epoch time.

回答1:

your class HistoricalData does not match the JSON structure. You could use a Map to match the JSON.

Map<Long, HistoryData> historicalData;

Then the class HistoryData would look like this:

class HistoryData {
    private Double score;
    private Long count;

    // getters & setters
}

Then you could process the map like:

historicalData.entrySet().forEach(entry -> {
    // do something with the entry
    // entry.getKey() would return the epochTime
    // entry.getValue() would return the HistoryData object
});

But to be honest it would be better if you could change the JSON structure to:

"historicalData": [
  { "epochTime": "1585573790000", “score”:23.54, “count”:3},
  { "epochTime": "1585487390000", “score”:12.65, “count”:2}
]

Then you could use a List of the class HistoricalData:

private List<HistoricalData> historicalData;

And the class would look like:

public class HistoricalData {
    private Long epochTime;
    private Double score;
    private Long count;

    // getters & setters
}

来源：https://stackoverflow.com/questions/60950529/parse-json-string-using-jaxson-root-value-customization