How do you parse and access the timestamp and reading in a JsonArray of arrays?

user_16034206 0
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I have a JsonObject that contains a JsonArray of arrays. I would like to parse it using Gson. The following is what the data looks like. I can use JsonArray data = resourceObj.get("data").getAsJsonArray() to get the outer array, but I m not sure how to access the inner array. My understanding is that to get something as a JsonArray it has to be in the form "xyz": [ something] or "xyz"=[something]

{
    "sid": "123456",
    "data": [
    [
      1595808000,
      0
    ],
    [
      1595894400,
      0
    ],
    [
      1595980800,
      0.0829
    ],
    [
      1596067200,
      0.0047
    ]
  ],
}
gson arrays java
2 Answers

The value of data is an array of arrays.

E.g. the value of data[2][1] is 0.0829.

What the second value of the inner array is, I don't know, but the first value looks like it is a Unix Timestamp.

E.g. value 1595980800 is Wednesday, July 29, 2020 12:00:00 AM GMT.

user_52211490

Also: if you have a string to parse so not using actual JsonObject and having such a stable JSON you can declare a wrapping data class to make handling more convenient and perhaps more type safe.

So something like this:

@Getter
@Setter
public static class MyData {
    private Long sid;
    @SuppressWarnings("serial")
    public static class DataItem extends ArrayList<Object> {
        public LocalDateTime getSomeLocalDateTime() {
            return Instant
                .ofEpochSecond(((Double)get(0)).longValue())
                .atZone(ZoneId.systemDefault())
                .toLocalDateTime();
        }
        public Double getSomeDouble() {
            return (Double)get(1);
        }
    }
    private List<DataItem> data; 
}

Use:

MyData myData = getGson().fromJson(json, MyData.class);
LocalDateTime ldt = myData.getData().get(0).getDate();
Double dbl = myData.getData().get(0).getSomeDouble();
user_64133770
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