I have a JSON file with some arrays in it. I want to iterate through the file arrays and get their elements and their values.
This is how my file looks like:
{
"JObjects": {
"JArray1": [
{
"A": "a",
"B": "b",
"C": "c"
},
{
"A": "a1",
"B": "b2",
"C": "c3",
"D": "d4"
"E": "e5"
},
{
"A": "aa",
"B": "bb",
"C": "cc",
"D": "dd"
}
]
}
}
This is how far I have come:
JSONObject object = new JSONObject("json-file.json");
JSONObject getObject = object.getJSONObject("JObjects");
JSONArray getArray = getObject.getJSONArray("JArray1");
for(int i = 0; i < getArray.size(); i++)
{
JSONObject objects = getArray.getJSONArray(i);
//Iterate through the elements of the array i.
//Get thier value.
//Get the value for the first element and the value for the last element.
}
Is it possible to do something like this?
The reason I want to do it like this is because the arrays in the file have a different number of elements.
for (int i = 0; i < getArray.length(); i++) {
JSONObject objects = getArray.getJSONObject(i);
Iterator key = objects.keys();
while (key.hasNext()) {
String k = key.next().toString();
System.out.println("Key : " + k + ", value : "
+ objects.getString(k));
}
// System.out.println(objects.toString());
System.out.println("-----------");
}
Hope this helps someone
You could try my (*heavily borrowed from various sites) recursive method to go through all JSON objects and JSON arrays until you find JSON elements. This example actually searches for a particular key and returns all values for all instances of that key. 'searchKey' is the key you are looking for.
ArrayList<String> myList = new ArrayList<String>();
myList = findMyKeyValue(yourJsonPayload,null,"A"); //if you only wanted to search for A's values
private ArrayList<String> findMyKeyValue(JsonElement element, String key, String searchKey) {
//OBJECT
if(element.isJsonObject()) {
JsonObject jsonObject = element.getAsJsonObject();
//loop through all elements in object
for (Map.Entry<String,JsonElement> entry : jsonObject.entrySet()) {
JsonElement array = entry.getValue();
findMyKeyValue(array, entry.getKey(), searchKey);
}
//ARRAY
} else if(element.isJsonArray()) {
//when an array is found keep 'key' as that is the array's name i.e. pass it down
JsonArray jsonArray = element.getAsJsonArray();
//loop through all elements in array
for (JsonElement childElement : jsonArray) {
findMyKeyValue(childElement, key, searchKey);
}
//NEITHER
} else {
//System.out.println("SKey: " + searchKey + " Key: " + key );
if (key.equals(searchKey)){
listOfValues.add(element.getAsString());
}
}
return listOfValues;
}
for(int i = 0; i < getArray.size(); i++){
Object object = getArray.get(i);
// now do something with the Object
}
You need to check for the type:
The values can be any of these types: Boolean, JSONArray, JSONObject, Number, String, or the JSONObject.NULL object. [Source]
In your case, the elements will be of type JSONObject, so you need to cast to JSONObject and call JSONObject.names()
to retrieve the individual keys.
JsonArray jsonArray;
Iterator<JsonElement> it = jsonArray.iterator();
while(it.hasNext()){
System.out.println(it.next());
}
Source: Stackoverflow.com