Convert ArrayList of HashMap into JSON String [duplicate]

Question

I want to convert ArrayList<Hashmap<String,String>> to JSONArray. I used

JSONArray array = new JSONArray(array_list);

but it does not work properly it returns

["{image=2130837526, category=Chairs, Quantity=1, price=400, name=chair, prodId=34}","{image=2130837566, category=Mirrors, Quantity=1, price=3000, name=La Fonda, prodId=35}"]

Instead it should return

cartitems=[{"name":"Chair","price":"1001","prodId":"2","category":"Chairs","image":"2130837519","Quantity":"1"},{"name":"Baxton Studio Club Chair","price":"4545","prodId":"5","category":"Chairs","image":"2130837521","Quantity":"1"}]

Answer 1

There are many ways to achieve that. I will explain two ways:

You can do like this:

ArrayList<HashMap<String, String>> dataMap = new ArrayList<HashMap<String, String>>();

HashMap<String, String> data1 = new HashMap<String, String>();
data1.put("image", "2130837526");
data1.put("category", "Chairs");
data1.put("Quantity", "1");

HashMap<String, String> data2 = new HashMap<String, String>();
data2.put("image", "2130837566");
data2.put("category", "Mirrors");
data2.put("Quantity", "2");

dataMap.add(data1);
dataMap.add(data2);


List<JSONObject> jsonObj = new ArrayList<JSONObject>();

for(HashMap<String, String> data : dataMap) {
    JSONObject obj = new JSONObject(data);
    jsonObj.add(obj);
}

JSONArray test = new JSONArray(jsonObj);

System.out.println(test.toString());

---

Or you can use Jackson Object Mapper:

Download Jackson Core

Download Jackson Mapper

Add external libraries to Eclipse Project

Adding a library/JAR to an Eclipse Android project

Java Code

ArrayList<HashMap<String, String>> dataMap = new ArrayList<HashMap<String, String>>();

HashMap<String, String> data1 = new HashMap<String, String>();
data1.put("image", "2130837526");
data1.put("category", "Chairs");
data1.put("Quantity", "1");

HashMap<String, String> data2 = new HashMap<String, String>();
data2.put("image", "2130837566");
data2.put("category", "Mirrors");
data2.put("Quantity", "2");

dataMap.add(data1);
dataMap.add(data2);

ObjectMapper objectMapper = new ObjectMapper();

String json = objectMapper.writeValueAsString(dataMap);

System.out.println(json);

Both options will print:

[{"image":"2130837526","category":"Chairs","Quantity":"1"},{"image":"2130837566","category":"Mirrors","Quantity":"2"}]