I have a web system that returns a json string with the data that I need in an Android App. The string is below:
[
{"id":1,
"title":"Remove ViRuSeS",
"tagline":"Remove ViRuSeS",
"body":"Body",
"image":"index.jpg",
"steps":[
{"id":2,
"title":"Step 1",
"body":"Download Things!",
"position":1}
]
}
]
It should return an array of objects, with one of the object's items also being an array of items.
I am familiar with gson and have gotten this working in the past, but I always had to simplify my data down to just an object, which makes me end up have to make multiple calls to get the data.
Is there a good way to do this without having to map all of the possible values back into classes?
My last attempt was to just try to get something simple out of this and am getting a NullPointerException on the second of these lines:
userDet = new JSONObject(string);
JSONArray userDetJson = userDet.getJSONArray("Steps");
change it to "steps" and not "Steps" , It will fix it:
userDet = new JSONObject(string);
JSONArray userDetJson = userDet.getJSONArray("steps");
The full parsing method:
JSONArray mainArray = new JSONArray(json);
for (int i = 0 ; i < mainArray.length() ; i ++)
{
JSONObject currentItem = array.getJSONObject(i);
String title = currentItem.getString("title");
String body = currentItem.getString("body ");
....
JSONArray currentItemStepsArray = currentItem.getJSONArray("steps");
for (int j = 0 ; j < currentItemStepsArray.length() ; j ++)
{
....
}
}
Here, try this:
JSONArray topLevelArr = new JSONArray(json);
JSONArray stepArr = topLevelArr.getJSONObject(0).getJSONArray("steps");
Related
I need to read a JSON file with following form:
{
"Data":[{
"foo":"22",
"bar":"33",
"array":[
{
"1foo":"22",
"1bar":"33"
},
{
"2foo":"22",
"2bar":"33",
}
],
"anotherData":{
"foofoo":"22",
"barbar":"33"
},
"some more data":"11",
"some more data":"11"
},
{and the cycle here starts again from -->
"foo":"22",
"bar":"33",
"array":[
My question stands : How do I access individual elements given it's sometimes JSONObject and sometimes JSONArray. I tried using org.json library but I'm failing to access anything after this line -> "array":[. I tried various combinations of JSONObject and JSONArray up to no avail.
My latest code looked something like this:
List<Data> data= new ArrayList<>();
String rawJson = getJsonAsString();
JSONObject outer = new JSONObject(rawJson);
JSONArray jArr= outer.getJSONArray("Data");
JSONObject inner= outer.getJSONObject("array");
for(int i =0; i<jArr.length(); i++){
JSONObject jsonEvent = jArr.getJSONObject(i);
String foo = jsonEvent.getString("foo"); <-- this works,
String 1foo = jsonEvent.getString("1foo"); <-- but this doesn't and i cant access it
I tried dozens of different solutions(tried myself and tried to find something here as well, but every case with those nested arrays is different and I can't add those solutions together to get answer for my case)
You can increase your readability if you beautify your raw JSON string:
{
"Data":[
{
"foo":"22",
"bar":"33",
"array":[
{
"1foo":"22",
"1bar":"33"
},
{
"2foo":"22",
"2bar":"33"
}
],
"anotherData":{
"foofoo":"22",
"barbar":"33"
},
"some more data":"11",
"some more data":"11"
},
{ and the cycle here starts again from -->
"foo":"22",
"bar":"33",
"array":[
...
],
...
}
]
}
So, stick to the following code:
JSONArray jArr = outer.getJSONArray("Data");
jArr is now filled with array of your Object.
And to loop through your Object array, you can use a for-loop which you have done it correctly.
for (int i = 0; i < jArr.length(); i++) {
// The below gets your Object
JSONObject jsonEvent = jArr.getJSONObject(i);
}
And now each jsonEvent contains your Object, which you can access the Object by their type.
For example, if you would like to access foo, you can use:
String foo = jsonEvent.getString("foo"); // foo = "22"
String bar = jsonEvent.getString("bar"); // bar = "33"
// Note that your array is another Array, you need to get it as JSONArray first
JSONArray arrayJson = jsonEvent.getJSONArray("array");
And as 1foo is in the first Object for your array, you need to access it like this:
JSONObject firstObjectInArray = arrayJson.getJSONObject(0);
String target = firstObjectInArray.getString("1foo"); // target = "22"
And to access foofoo, as it is an attribute of the JSON Object anotherData, so you should obtain anotherData as JSONObject first, and then you can access foofoo:
JSONObject anotherDataObject = jsonEvent.getJSONObject("anotherData");
String foofoo = anotherDataObject.getString("foofoo"); // foofoo = "22"
So the full code within your for-loop should look like this:
for (int i = 0; i < jArr.length(); i++) {
// The below gets your Object
JSONObject jsonEvent = jArr.getJSONObject(i);
String foo = jsonEvent.getString("foo");
JSONArray arrayJson = jsonEvent.getJSONArray("array");
String target = arrayJson.getJSONObject(0).getString("1foo");
// Add to get foofoo
JSONObject anotherDataObject = jsonEvent.getJSONObject("anotherData");
String foofoo = anotherDataObject.getString("foofoo");
}
I have a java project in which I take a JSON and read its contents. I'm using org.json libraries and I would like to iterate through JSONObjects which are nested in a JSONArray, which is nested in a JSONObject. I keep getting this error though: JSONArray initial value should be a string or collection or array. I'm specifically getting the JSON from a web source, but here is an example of one: http://jsonblob.com/1062033947625799680
I'm particularly concerned about the fact that each player profile is unnamed, but there may be a simple fix for that.
I'd like to get access to each player profile and here is what I have that is causing an error:
import org.json.*;
JSONObject JSON = new JSONObject(content1.toString());
JSONArray data = new JSONArray(JSON.getJSONArray("data"));
for(int z = 1; i<data.length(); i++)
{
JSONObject ply = new JSONObject(data.getJSONObject(z));
System.out.println(ply.toString());
}
I have a feeling I just don't fully understand the terminology of JSON and/or the library that I'm using, but any help is appreciated.
Try this instead:
JSONObject JSON = new JSONObject(content1.toString());
JSONArray data = new JSONArray(JSON.getJSONArray("data"));
for(int i = 0; i<data.length(); i++) {
JSONObject ply = data.getJSONObject(i);
System.out.println(ply.toString());
}
It turns out I just have to access the particular element in one line:
JSONObject JSON = new JSONObject(content1.toString());
JSONArray data = JSON.getJSONArray("data");
for(int z = 0; z<data.length(); z++)
{
//JSONObject ply = new JSONObject(data.getJSONObject(z));
String name = data.getJSONObject(z).getString("skaterFullName");
System.out.println(name);
}
{"balance":1000.21,"is_vip":true,"num":100,"name":"foo"}
This is my json string. I want to iterate each element and get my output as
1000
true
100
foo
I tried creating JSONArray with the following syntax
JSONArray jsonarr = new JSONArray(myString);
But the error thrown is
"The constructor JSONArray(String) is undefined"
So what can be the possible solution this?
You have to use JSONObject class instead:
JSONObject jso = new JSONObject(yourJsonString);
// values
for(int i = 0; i<jso.names().length(); i++){
System.out.println( jso.get( jso.names().getString(i) ) );
}
I have a JSON Object which converted into String and saved into database .But when i am trying to get it back it is throwing exception.My object is something like that...
{"COLUMN":["Type","Sub Type","F.P.","P.P.","Process","Due To Start"]}
How can we get the data back in Normal form?
My Java Code is.....
JSONObject obj = new JSONObject();
JSONArray the_json_array = obj.getJSONArray(userReorderOption);
int size = the_json_array.size();
ArrayList<JSONObject> arrays = new ArrayList<JSONObject>();
for (int i = 0; i < size; i++) {
JSONObject another_json_object = the_json_array.getJSONObject(i);
arrays.add(another_json_object);
}
And Exception i am getting....
net.sf.json.JSONException: JSONObject["{\"TASKLIST_COLUMN_REORDER\":[\"Type\",\"Sub Type\",\"F.P.\",\"P.P.\",\"Process\",\"Due To Start\"]}"] is not a JSONArray.
And this is java Code how i am creating JSON Object and saving into database...
String userReorderSelection;
Set set = new LinkedHashSet(userReorderSelection);
JSONObject json = new JSONObject();
json.accumulate("COLUMN", set);
saveJSONObj("PrimaryKeyColumn", json.toString());
Thanks Tichodroma,
But as i told i am using net.sf.json.JSONObject class and above things we can achieve from this class too..What i did to solve the above issue?...Please have a look on the Java code...
JSONObject jsonObj = new JSONObject();
JSONObject obj = jsonObj.fromObject(userReorderOption);
JSONArray columnName = (JSONArray) obj.get("COLUMN");
for (int i = 0; i < columnName.size(); i++) {
System.out.println(columnName.getString(i));
}
This code work fine for me with my Json Jar**(net.sf.json)**
Your JSON is not a JSONArray.
A JSONArray is an ordered sequence of values.
You have a JSONObject.
A JSONObject is an unordered collection of name/value pairs.
Edit:
Using the JSON implementation from org.codehaus.jettison.json, you can do this:
String json = "{\"COLUMN\":[\"Type\",\"Sub Type\",\"F.P.\",\"P.P.\",\"Process\",\"Due To Start\"]}";
JSONObject obj = new JSONObject(json);
JSONArray column = (JSONArray) obj.get("COLUMN");
for (int i = 0; i < column.length(); i++) {
final String field = column.getString(i);
System.out.println(field);
}
Result:
Type
Sub Type
F.P.
P.P.
Process
Due To Start
I am using the package org.json package: I need help with getting the corect data from the json in java. this is the string I have in json:
{"GetLocationsResult":[{"ID":82,"Name":"Malmo","isCity":true,"isCounty":false,"isDisctrict":false,"ID_Parent":null,"ID_Map":35,"ZipCode":"7000"},{"ID":82,"Name":"Trelleborg","isCity":true,"isCounty":false,"isDisctrict":false,"ID_Parent":null,"ID_Map":35,"ZipCode":"7000"}]}
This is a listing and this is just a test, it will contain more than 2 items, so my questions is, I want to get the name of all locations, I want to populate a spinner with names in my android app.
How can I get the "Name":"Malmo" and so on....
???
The answer is simple....The JSON element starts with a { which is a JSON Object, and GetLocationsResults is a JSON Array of JSON Objects. In essence, I translated the JSON String to the following code...
JSONObject rootJson = new JSONObject(jsonString);
JSONArray jsonArray = rootJson.getJSONArray("GetLocationsResult");
//Let's assume we need names....
String[] names = null;
if (jsonArray != null) {
names = new String[jsonArray.length()];
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject json = jsonArray.getJSONObject(i);
names[i] = json.getString("Name");
}
}
//Test
for (String name: names) {
System.out.println(name);
}