ArrayList<String> list = new ArrayList<String>();
JSONArray jsonArray = (JSONArray)jsonObject;
if (jsonArray != null) {
int len = jsonArray.length();
for (int i=0;i<len;i++){
list.add(jsonArray.get(i).toString());
}
}
Answer from Pentium10 on Stack OverflowArrayList<String> list = new ArrayList<String>();
JSONArray jsonArray = (JSONArray)jsonObject;
if (jsonArray != null) {
int len = jsonArray.length();
for (int i=0;i<len;i++){
list.add(jsonArray.get(i).toString());
}
}
If you don't already have a JSONArray object, call
JSONArray jsonArray = new JSONArray(jsonArrayString);
Then simply loop through that, building your own array. This code assumes it's an array of strings, it shouldn't be hard to modify to suit your particular array structure.
List<String> list = new ArrayList<String>();
for (int i=0; i<jsonArray.length(); i++) {
list.add( jsonArray.getString(i) );
}
How to turn json objects into an array of json objects using Java?
java - Convert JSONArray to String Array - Stack Overflow
json - Accessing members of items in a JSONArray with Java - Stack Overflow
JSON Array to Java objects - Stack Overflow
Videos
for your example:
{'profiles': [{'name':'john', 'age': 44}, {'name':'Alex','age':11}]}
you will have to do something of this effect:
JSONObject myjson = new JSONObject(the_json);
JSONArray the_json_array = myjson.getJSONArray("profiles");
this returns the array object.
Then iterating will be as follows:
int size = the_json_array.length();
ArrayList<JSONObject> arrays = new ArrayList<JSONObject>();
for (int i = 0; i < size; i++) {
JSONObject another_json_object = the_json_array.getJSONObject(i);
//Blah blah blah...
arrays.add(another_json_object);
}
//Finally
JSONObject[] jsons = new JSONObject[arrays.size()];
arrays.toArray(jsons);
//The end...
You will have to determine if the data is an array (simply checking that charAt(0) starts with [ character).
Hope this helps.
You can prefer quick-json parser to meet your requirement...
quick-json parser is very straight forward, flexible, very fast and customizable. Try this out
[quick-json parser] (https://code.google.com/p/quick-json/) - quick-json features -
Compliant with JSON specification (RFC4627)
High-Performance JSON parser
Supports Flexible/Configurable parsing approach
Configurable validation of key/value pairs of any JSON Heirarchy
Easy to use # Very Less foot print
Raises developer friendly and easy to trace exceptions
Pluggable Custom Validation support - Keys/Values can be validated by configuring custom validators as and when encountered
Validating and Non-Validating parser support
Support for two types of configuration (JSON/XML) for using quick-json validating parser
Require JDK 1.5 # No dependency on external libraries
Support for Json Generation through object serialization
Support for collection type selection during parsing process
For e.g.
JsonParserFactory factory=JsonParserFactory.getInstance();
JSONParser parser=factory.newJsonParser();
Map jsonMap=parser.parseJson(jsonString);
Hi. I'm new to java and stuck wondering how I would go about turning something like this: {} {} {} into this: [{},{},{}]. I'm trying to figure out how to do this to my incoming json data using Java. The data has like 20 similar objects, with the same keys but with constantly changing values.
Any help is much appreciated.
Sincerely,
your friendly neighborhood noob
Take a look at this tutorial. Also you can parse above json like :
JSONArray arr = new JSONArray(yourJSONresponse);
List<String> list = new ArrayList<String>();
for(int i = 0; i < arr.length(); i++){
list.add(arr.getJSONObject(i).getString("name"));
}
Simplest and correct code is:
public static String[] toStringArray(JSONArray array) {
if(array==null)
return new String[0];
String[] arr=new String[array.length()];
for(int i=0; i<arr.length; i++) {
arr[i]=array.optString(i);
}
return arr;
}
Using List<String> is not a good idea, as you know the length of the array.
Observe that it uses arr.length in for condition to avoid calling a method, i.e. array.length(), on each loop.
Have you tried using JSONArray.getJSONObject(int), and JSONArray.length() to create your for-loop:
for (int i = 0; i < recs.length(); ++i) {
JSONObject rec = recs.getJSONObject(i);
int id = rec.getInt("id");
String loc = rec.getString("loc");
// ...
}
An org.json.JSONArray is not iterable.
Here's how I process elements in a net.sf.json.JSONArray:
JSONArray lineItems = jsonObject.getJSONArray("lineItems");
for (Object o : lineItems) {
JSONObject jsonLineItem = (JSONObject) o;
String key = jsonLineItem.getString("key");
String value = jsonLineItem.getString("value");
...
}
Works great... :)
assuming your json string data is stored in variable called jsonStr:
String jsonStr = getJsonFromSomewhere();
Gson gson = new Gson();
Click clicks[] = gson.fromJson(jsonStr, Click[].class);
Check out the Gson API and some examples. I've put the links below!
String jsonString = //your json String
Gson gson = new Gson();
Type typeOfList = new TypeToken<List<Map<String, Integer>>>() {}.getType();
List<Map<String, Integer>> list = gson.fromJson(jsonString, typeOfMap);
List<Click> clicks = new ArrayList<Click>();
for(int i = 0; i < list.size(); i++) {
int x = list.get(i).get("x");
int y = list.get(i).get("y");
clicks.add(new Click(x, y));
}
(http://google-gson.googlecode.com/svn/trunk/gson/docs/javadocs/com/google/gson/Gson.html) (http://google-gson.googlecode.com/svn/tags/1.5/src/test/java/com/google/gson/functional/MapTest.java)