Parsing a JSON object within a JSON object - java

I have a JSON file which contains an array of item objects:
{
"item": [
{
"title": "TitleA",
"link": "http://www.abc.html?partner=rss&emc=rss",
"guid": {
"-isPermaLink": "true",
"#text": "www.abc.html"
},
"atom:link": {
"-rel": "standout",
"-href": "http://www.abc.html?partner=rss&emc=rss"
},
"media:content": {
"-url": "standard.jpg",
"-medium": "image",
"-height": "75",
"-width": "75"
},
"media:description": "This is the description.",
"media:credit": "Reuters",
"description": "In depth description",
"dc:creator": "By test creator",
"pubDate": "Sun, 21 Oct 2012 11:29:12 GMT",
"category": "World"
},
{
"title": "TitleB",
"link": "http://www.abc.html?partner=rss&emc=rss",
"guid": {
"-isPermaLink": "true",
"#text": "www.abc.html"
},
"atom:link": {
"-rel": "standout",
"-href": "http://www.abc.html?partner=rss&emc=rss"
},
"media:content": {
"-url": "standard.jpg",
"-medium": "image",
"-height": "75",
"-width": "75"
},
"media:description": "This is the description.",
"media:credit": "Reuters",
"description": "In depth description",
"dc:creator": "By test creator",
"pubDate": "Sun, 21 Oct 2012 11:29:12 GMT",
"category": "World"
}
]
}
Now I know how to get the "title", but I don't know how I would access the "-url" within "media:content" for example, since it seems to be a JSON object within the Item object. How would I get this value and assign it to a value in my Item class?

try as to get "-url" within "media:content" from current json string :
JSONObject jsonObject = new JSONObject("Your JSON STRING HERE");
JSONArray jsonArray =jsonObject.getJSONArray("item");
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObjectitem=
jsonArray.getJSONObject(i);
// get title or link here
String strtitle=jsonObjectitem.getString("title");
//....get other values in same way
// get media:content json object
JSONObject jsonObjectmediacontent =
jsonObjectitem.getJSONObject("media:content");
// get url,medium,...
String strurl=jsonObjectmediacontent.getString("-url");
//....get other values in same way
}

Write below code to parse -url string, it will solve your problem.
JSONObject mMainJsonObj = new JSONObject("Pass Json Response String Here");
JSONArray mItemJsonArray = mMainJsonObj.getJSONArray("item");
for (int i = 0; i < mItemJsonArray.length(); i++) {
JSONObject mJsonObj1 = mItemJsonArray.getJSONObject(i);
String mTitle = mJsonObj1.getString("title");
String mLink = mJsonObj1.getString("link");
JSONObject mJsonObjGuid = mJsonObj1.getJSONObject("guid");
String mIsPermLink = mJsonObjGuid.getString("-isPermaLink");
String mText = mJsonObjGuid.getString("#text");
JSONObject mJsonObjAtomLink = mJsonObj1.getJSONObject("atom:link");
String mRel = mJsonObjAtomLink.getString("-rel");
String mHref = mJsonObjAtomLink.getString("-href");
JSONObject mJsonObjMediaContent = mJsonObj1.getJSONObject("media:content");
String mUrl = mJsonObjMediaContent.getString("-url");
String mMedium = mJsonObjMediaContent.getString("-medium");
String mHeight = mJsonObjMediaContent.getString("-height");
String mWidth = mJsonObjMediaContent.getString("-width");
}
And see below link for more information.
Json Parsing Example

Solution with Jackson: read your JSON into a JsonNode using an ObjectMapper and retrieve your values like this:
// Since JsonNode implements Iterable of itself and cycles through array elements,
// this works
for (final JsonNode element: node)
doSomethingWith(element.get("media:content").get("-url"));

Related

how to covert JSONObject to another Required JSONObect by mapping AccountId using java

**My result of JSONObject to convert as follows bellow code and have searched for many this how to convert using java but I converted that **
{
"result": {
"accountnames": [{
"accountName": "Hari",
"accountId": 878488
}, {
"accountName": "ravi",
"accountId": 878487
}],
"sales": [{
"accountSales": "89",
"accountId": 878488
}, {
"accountName": "98",
"accountId": 878487
}],
"countResult": [{
"accountResult": "945",
"accountId": 878488
}, {
"accountResult": "9452",
"accountId": 878489
}]
}
}
*and this is where the sample code to be converted *
{
"result": [{
"accountName": "Hari",
"accountSales": "89",
"accountResult": "945",
"accountId": 878488
},
{
"accountName": "ravi",
"accountSales": "98",
"accountId": 878487
},
{
"accountResult": "9452",
"accountId": 878489
}
]
}
My required JSON data has to be formatted as below
You need to group all the elements by accountId. You can use something like this depending on the json library that you are using.
Initialize the json object:
JSONObject rootJson = new JSONObject(json);
JSONObject resultJson = rootJson.getJSONObject("result");
Create a map to hold the objects by accountId:
Map<String, JSONObject> accountIds = new HashMap<>();
Then iterate for each key in the json, then for each element in the arrays and then for each property of the object inside the json:
Iterator mainKeys = resultJson.keys();
while (mainKeys.hasNext()) {
String key = (String) mainKeys.next();
JSONArray array = resultJson.getJSONArray(key);
for (int index = 0; index < array.length(); index++) {
JSONObject object = array.getJSONObject(index);
if (object.has("accountId")) {
String accountId = object.get("accountId").toString();
JSONObject accum = accountIds
.computeIfAbsent(accountId, (k) -> new JSONObject());
// depending on the json impl you can use putAll or similar
Iterator objKeys = object.keys();
while (objKeys.hasNext()) {
String property = (String) objKeys.next();
accum.put(property, object.get(property));
}
} else {
// does not have account id, ignore or throw
}
}
}
Finally create the json file and add the elements to the JSONArray:
JSONObject finalJson = new JSONObject();
finalJson.put("result", new JSONArray(accountIds.values()));
System.out.println(finalJson.toString());
(note: the json has an error in sales array accountName instead of accountSales)

how to get elements from JSONObject and write it to file

i have a following JSONObject
{"elements": [
{
"name": "StartLabelFormat",
"value": "^XA"
},
{
"name": "shipperAddressLine1",
"value": "Street1",
"format": {"Text": {
"orientation": "N",
"height": "28",
"width": 20,
"fontname": 0,
"y": 373,
"x": 20
}}
},
{
"name": "EndLabelFormat",
"value": "^XZ"
}
]}
Now i want to get element from this Object and write it to a file.
For Example, for this block
{
"name": "shipperAddressLine1",
"value": "Street1",
"format": {"Text": {
"orientation": "N",
"height": "28",
"width": 21,
"fontname": 0,
"y": 373,
"x": 20
}}
},
I want to write in file as
^FT 20, 373 ^A0N, 28, 21 ^FDStreet1^FS.
Please help me to do this.
How to do it ?
If you meet {} in your code , you can use JSONObject to parse it .
If you meet [] in your code , you can use JSONArray to parse it .
And if you meet [] in your code , you can use for loop to get value in it .
And you should use try catch in your code .
Try this in your code .
try {
JSONObject jsonObject = new JSONObject(response);
JSONArray elements = jsonObject.getJSONArray("elements");
for (int i = 0; i < elements.length(); i++) {
JSONObject jsonObject1 = elements.getJSONObject(i);
String name = jsonObject1.optString("name");
String value = jsonObject1.optString("value");
JSONObject format = jsonObject1.optJSONObject("format");
JSONObject Text = format.optJSONObject("Text");
String orientation = Text.optString("orientation");
String height = Text.optString("height");
String width = Text.optString("width");
}
} catch (JSONException e) {
e.printStackTrace();
}
Note
And use optString and optJSONObject in your code . If format is null ,it will not return error .
And you can judge that JSONArray's length is not 0 and not null in the code .
To get this element from JsonArray
JsonObject yourElement = yourJsonArray.get(index);
Simply, you can use gson library for parsing json to objects.
public class Staff {
private String name;
private String value;
//...
and use Gson
String jsonInString = " {
"name": "shipperAddressLine1",
"value": "Street1"
}";
Staff staff = gson.fromJson(yourElement.toString() , Staff.class);
After that you can write in file by using your custom toString() method inside Staff class.
P.S. to convert JsonObject to String you can use also toString() method.

How to access JSON data with multiple array objects : android

I am stuck in getting the data from the JSON file with multiple data sets.
{
"status": "ok",
"count": 3,
"count_total": 661,
"pages": 133,
"posts": [
{
"id": 20038,
"type": "post",
"slug": "xperia-launcher-download",
"url": "http:\/\/missingtricks.net\/xperia-launcher-download\/",
"status": "publish",
"title": "Download Xperia Launcher app for Android (Latest Version)"
},
{
"id": 94,
"type": "post",
"slug": "top-free-calling-apps-of-2014-year",
"url": "http:\/\/missingtricks.net\/top-free-calling-apps-of-2014-year\/",
"status": "publish",
"title": "Best Free Calling Apps for Android November 2014"
},
{
"id": 98,
"type": "post",
"slug": "top-free-calling-apps-of-2016-year",
"url": "http:\/\/missingtricks.net\/top-free-calling-apps-of-2016-year\/",
"status": "publish",
"title": "Best Free Calling Apps for Android December 2016"
}
]
}
I need to access the title, url and status from the above JSON file.
#Override
protected void onPostExecute(String result) {
//this method will be running on UI thread
pdLoading.dismiss();
List<DataFish> data = new ArrayList<>();
pdLoading.dismiss();
try {
JSONArray jArray = new JSONArray(result);
// Extract data from json and store into ArrayList as class objects
for (int i = 0; i < jArray.length(); i++) {
JSONObject json_data = jArray.getJSONObject(i);
DataFish fishData = new DataFish();
fishData.status = json_data.getString("status");
fishData.title = json_data.getString("url");
fishData.sizeName = json_data.getString("title");
data.add(fishData);
}
} catch (JSONException e) {
Toast.makeText(JSonActivity.this, e.toString(), Toast.LENGTH_LONG).show();
Log.d("Json","Exception = "+e.toString());
}
}
I am getting a JSONException with the above code.
What should I do to access the title,status and url from the JSON File?
You have to fetch your JSONArray which is inside a JSONObject , so create a JSONObject and fetch your array with index "posts"
1.) result is a JSONObject so create a JSONObject
2.) Fetch your JSONArray with index value as "posts"
3.) Now simply traverse array objects by fetching it through index
JSONObject jObj = new JSONObject(result);
JSONArray jArray = jObj.getJSONArray("posts");
// Extract data from json and store into ArrayList as class objects
for (int i = 0; i < jArray.length(); i++) {
JSONObject json_data = jArray.getJSONObject(i);
DataFish fishData = new DataFish();
fishData.status = json_data.getString("status");
fishData.title = json_data.getString("url");
fishData.sizeName = json_data.getString("title");
data.add(fishData);
}
Note : i don't know weather it is a sample response with shorter version though your json object should ends with } not with , .
[{"id":20038,"type":"post","slug":"xperia-launcher-download","url":"http://missingtricks.net/xperia-launcher-download/","status":"publish","title":"Download
Xperia Launcher app for Android (Latest Version)",
// ^^^ there should be a } not a , to end json
// so make sure to do the correction so it will look like => ...st Version)"},
{"id":94,"type":"post","slug":"top-free-calling-apps-of-2014-year","url":"http://missingtricks.net/top-free-calling-apps-of-2014-year/","status":"publish","title":"Best
Free Calling Apps for Android November 2014", ]
Improvements :
you can use optString to avoid null or non-string value if there is no mapping key
This has two variations
Get an optional string associated with a key. It returns the
defaultValue if there is no such key.
public String optString(String key, String defaultValue) {
fishData.status = json_data.optString("status","N/A");
// will return "N/A" if no key found
or To get empty string if no key found then simply use
fishData.status = json_data.optString("status");
// will return "" if no key found where "" is an empty string
You can validate your JSON here.
If entire JSON getJsonObject() is not working, then you should parse JSON objects & array in multiple arrays then use them.

How to decode JSONObject

This question is related with my previous question
I can successfully get the String in json format from the URL to my spring controller
Now I have to decode it
so I did like the following
#RequestMapping("/saveName")
#ResponseBody
public String saveName(String acc)
{jsonObject = new JSONObject();
try
{
System.out.println(acc);
org.json.JSONObject convertJSON=new org.json.JSONObject(acc);
org.json.JSONObject newJSON = convertJSON.getJSONObject("nameservice");
System.out.println(newJSON.toString());
convertJSON = new org.json.JSONObject(newJSON.toString());
System.out.println(jsonObject.getString("id"));
}
catch(Exception e)
{
e.printStackTrace();jsonObject.accumulate("result", "Error Occured ");
}
return jsonObject.toString();
}
This is the JSON String { "nameservice": [ { "id": 7413, "name": "ask" }, { "id": 7414, "name": "josn" }, { "id": 7415, "name": "john" }, { "id": 7418, "name": "RjhjhjR" } ] }
When I run the code then I get the error
org.json.JSONException: JSONObject["nameservice"] is not a JSONObject.
What wrong I am doing?
It's not a JSONObject, it's a JSONArray
From your question:
{ "nameservice": [ { "id": 7413, "name": "ask" }, { "id": 7414, "name": "josn" }, { "id": 7415, "name": "john" }, { "id": 7418, "name": "RjhjhjR" } ] }
The [ after the nameservice key tells you it's an array. It'd need to be a { to indicate an object, but it isn't
So, change your code to use it as a JSONArray, then iterate over the contents of that to get the JSONObjects inside it, eg
JSONArray nameservice = convertJSON.getJSONArray("nameservice");
for (int i=0; i<nameservice.length(); i++) {
JSONObject details = nameservice.getJSONObject(i);
// process the object here, eg
System.out.println("ID is " + details.get("id"));
System.out.println("Name is " + details.get("name"));
}
See the JSONArray javadocs for more details
It seems you're trying to get a JSONObject when "nameservice" is an array of JSONObjects and not an object itself. You should try this:
JSONObject json = new JSONObject(acc);
JSONArray jsonarr = json.getJSONArray("nameservice");
for (int i = 0; i < jsonarr.length(); i++) {
JSONObject nameservice = jsonarr.getJSONObject(i);
String id = nameservice.getString("id");
String name = nameservice.getString("name");
}
I don't understand why you do it manualy if you already have Spring Framework.
Take a look at MappingJackson2HttpMessageConverter and configure your ServletDispatcher accordingly. Spring will automatically convert your objects to JSON string and vice versa.
After that your controller method will be looked like:
#RequestMapping("/saveName")
#ResponseBody
public Object saveName(#RequestBody SomeObject obj) {
SomeObject newObj = doSomething(obj);
return newObj;
}

Nested JSONObject

I am having several problems with JSONObjects and JSONArray.
I would like to parse this json file:
[{
"SourceFile": "AndresIniesta.flv",
"ExifTool": {
"ExifToolVersion": 8.22
},
"System": {
"FileName": "AndresIniesta.flv",
(...)
},
"File": {
"FileType": "FLV",
"MIMEType": "video/x-flv"
},
"Flash": {
"Duration": "04:09",
"Starttime": 0,
"Totalduration": 249.36,
"ImageWidth": 320,
(...)
},
"Composite": {
"ImageSize": "320x240"
}
}]
But not all of them, just the field Flash.
The whole file is an JSONArray, but with just 1 element. I got the Flash filled with this piece of code:
JsonMappingException, IOException {
String a = new String();
InputStream is =
this.getClass().getClassLoader().getResourceAsStream(
"a.json");
String jsonTxt = IOUtils.toString(is);
JSONArray json = (JSONArray) JSONSerializer.toJSON(jsonTxt);
JSONObject flash = json.getJSONObject(0);
System.out.print("flash -> " + flash.getString("Flash"));
But I don't know hoy to access to each one of Flash fild, lis Duration, Starttime... etc.
When I try it like this:
String canseekontime =
flash.getString("Canseekontime");
int starttime =
flash.getInt("Starttime");
Double duration = flash.getDouble("Duration");
I get this error:
net.sf.json.JSONException: JSONObject["Duration"] not found.
Any help??
Thanks in advance
You mean
JSONObject flash = json.getJSONObject(0);
JSONObject Flash = flash.getJSONObject("Flash");
int starttime = Flash.getInt("Starttime");

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