CODEWITHSUNDEEP
javajson
NIKHIL K A
NIKHIL K A

Reputation: 328

Grouping same date JSON data together Using java

I have created one json Object Using java and it's values are given below 

{
  "result":[
    {"ID":7252,"Age":52,"Date":"2015-11-25","DAY":"Wednesday","Gender":"M"},
    {"ID":7252,"Age":52,"Date":"2015-12-05","DAY":"Saturday","Gender":"M"},
    ....
  ],
  "status":"ok"
}

I need to group data as per date,required format is given below

{
  "result":[
    {"2015-11-25":[
      {"ID":7252,"Age":52,"Date":"2015-11-25","DAY":"Wednesday","Gender":"F"},
      {"ID":7252,"Age":52,"Date":"2015-11-25","DAY":"Wednesday","Gender":"M"}
    ]},
    {"2015-10-25":[
      {"ID":7252,"Age":52,"Date":"2015-10-25","DAY":"Tuesday","Gender":"F"},
      {"ID":7252,"Age":52,"Date":"2015-10-25","DAY":"Tuesday","Gender":"M"}
    ]},
  ],
  "status":"ok"
}

Basically i need group all same date data together inside JSON with date as key How can i achieve this JSON format using java

Upvotes: 2

Views: 3017

Answers (2)

Raymond Choi
Raymond Choi

Reputation: 1271

You can use JSON library such as Josson to do the transformation.

https://github.com/octomix/josson

Josson josson = Josson.fromJsonString(
    "{" +
    "  \"result\":[" +
    "    {\"ID\":7252,\"Age\":52,\"Date\":\"2015-11-25\",\"DAY\":\"Wednesday\",\"Gender\":\"M\"}," +
    "    {\"ID\":7252,\"Age\":52,\"Date\":\"2015-12-05\",\"DAY\":\"Saturday\",\"Gender\":\"M\"}," +
    "    {\"ID\":7252,\"Age\":52,\"Date\":\"2015-11-25\",\"DAY\":\"Wednesday\",\"Gender\":\"F\"}," +
    "    {\"ID\":7252,\"Age\":52,\"Date\":\"2015-12-05\",\"DAY\":\"Saturday\",\"Gender\":\"F\"}" +
    "  ]," +
    "  \"status\":\"ok\"" +
    "}");
JsonNode node = josson.getNode("field(result.group(Date).map(Date::elements))");
System.out.println(node.toPrettyString());

Output

{
  "result" : [ {
    "2015-11-25" : [ {
      "ID" : 7252,
      "Age" : 52,
      "Date" : "2015-11-25",
      "DAY" : "Wednesday",
      "Gender" : "M"
    }, {
      "ID" : 7252,
      "Age" : 52,
      "Date" : "2015-11-25",
      "DAY" : "Wednesday",
      "Gender" : "F"
    } ]
  }, {
    "2015-12-05" : [ {
      "ID" : 7252,
      "Age" : 52,
      "Date" : "2015-12-05",
      "DAY" : "Saturday",
      "Gender" : "M"
    }, {
      "ID" : 7252,
      "Age" : 52,
      "Date" : "2015-12-05",
      "DAY" : "Saturday",
      "Gender" : "F"
    } ]
  } ],
  "status" : "ok"
}

Upvotes: 0

Benjamin M
Benjamin M

Reputation: 24527

What kind of JSON mapper do you use? Jackson, GSON, ...?

And please provide some code. So we can see what you're doing.

If you created the JSON object using Java, you should have a Java Object structure, right?

Something like this:

class Data {
  int id;
  int age;
  LocalDate date;
  ...
}

And somewhere an Array / List of your data:

List<Data> result = new ArrayList<>();
result.add(data1);
result.add(data2);
result.add(data3);

Then you can use Java8 Stream API to group your data:

Map<LocalDate, Data> grouped = result
    .stream()
    .collect(
        Collectors.groupingBy(Data::getDate)
    );

The result will be a Map. Your result should be a List.

So you should be able to simply iterate over the Map and insert it into a new List.

Upvotes: 4

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