Converting JSONArray to HashMap and Matching

Question

I have a JSONArray that has data in following format :

[[{ "Country" : "IN", "count" : 10},{ "Country" : "US", "count" : 20}],
[{ "Country" : "IN", "count" : 10},{ "Country" : "US", "count" : 20}]]

I want to put the data to an HashMap, something like this :

"IN":10
"US":20
"IN":10
"US":20

Basically, I am doing a count match so as to ensure all Country of a type have same count.

Here is what I tried, JSONArray is stored as myArray :

Map<String, Integer> cargo = new HashMap<>();
for (int j = 0; j < myArray.length(); j++) {
  String country = myArray.getJSONObject(j).getString("country");
  Integer count = myArray.getJSONObject(j).getInt("count");
  cargo.put(country, count);
}

But I get JSONArray[0] is not a JSONObject error.

Thanks,

Edit : This helped me get it to map.

`

Map<String, Integer> cargo = new HashMap<>();
for (int j = 0; j < myArray.length(); j++) {
  for (int k = 0; k < myArray.getJSONArray(j).length(); k++) {
    String country = myArray.getJSONArray(j).getJSONObject(k).getString("country");
    Integer count = myArray.getJSONArray(j).getJSONObject(k).getInt("count");
    cargo.put(country, count);
  }

`

Your json is an array of arrays so you need an extra loop over each array. — Abdennacer Lachiheb
– Abdennacer Lachiheb, Commented Sep 6, 2017 at 10:12

Orelsanpls · Accepted Answer · 2017-09-06 10:12:16Z

1

Your JSONArray[0] equals to

[{ "Country" : "IN", "count" : 10},{ "Country" : "US", "count" : 20}]

So not an JSONObject indeed, you need to do a for inside a for, to iterate every object.

for (int j = 0; j < myArray.length(); j++) {
  for (int k = 0; k < myArray[j].length(); k++) {
    String country = myArray[j].getJSONObject(k).getString("country");
    Integer count = myArray[j].getJSONObject(k).getInt("count");
    cargo.put(country, count);
  }
}

answered Sep 6, 2017 at 10:12

Orelsanpls

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3 Comments

AYa Over a year ago

Well, I tried this, But for the second loop, I get the type of the expression should be an array type but it resolved to JSONArray.

Orelsanpls Over a year ago

So find a way to loop an JSONArray :)

AYa Over a year ago

Ya. I found. Updated the question.

Abdennacer Lachiheb · Accepted Answer · 2017-09-06 10:12:58Z

0

Your json is an array of arrays so you need an extra loop over each array.

answered Sep 6, 2017 at 10:12

Abdennacer Lachiheb

4,9689 gold badges35 silver badges66 bronze badges

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