I'm currently parsing a JSON file to my Java Program and I ecounter a problem.
I get a JSON array that can look like this for example:
[
{
"itemType": "magazineArticle",
"creators": [
{
"firstName": "J. Antonio",
"lastName": "Garcia-Macias",
"creatorType": "author"
},
{
"firstName": "Jorge",
"lastName": "Alvarez-Lozano",
"creatorType": "author"
},
{
"firstName": "Paul",
"lastName": "Estrada-Martinez",
"creatorType": "author"
},
{
"firstName": "Edgardo",
"lastName": "Aviles-Lopez",
"creatorType": "author"
}
],
"notes": [],
"tags": [],
"title": "Browsing the Internet of Things with Sentient Visors",
"publicationTitle": "Computer",
"volume": "44",
"issue": "5",
"ISSN": "0018-9162",
"date": "2011",
"pages": "46-52",
"abstractNote": "Unlike the traditional Internet, the emerging Internet of Things constitutes a mix of virtual and physical entities. A proposed IoT browser enables the exploration of augmented spaces by identifying smart objects, discovering any services they might provide, and interacting with them.",
"extra": "CICESE Research Center, Mexico; CICESE Research Center, Mexico; CICESE Research Center, Mexico; CICESE Research Center, Mexico",
"libraryCatalog": "IEEE Computer Society"
}
]
The problem is I have to do a check each time I parse if the field called "extra" is in the array, since it's not included every time i parse.
So how do I do that check to see if the field "extra" exists?
Without framework, you can use JSONObject and JSONArray from org.json.*. Here is an example (not tested). It will allows you to check if the extra key is present
String jsonAsString = "/*Your json as a String*/";
JsonArray jsonArray = new JSONArray(jsonAsString);
for(int i=0; i<jsonArray.length(); i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
//Get values from your jsonObject
jsonObject.has("extra"); //Check if extra is present
}
Use "has" method of JSONObject like this:
Array.getJSONObject(j).has("extra")
Related
I can get other fields correctly, but can parse the "title" or "title_full" values. I always receives an empty string. I am using the org.json library. This is the json. What's the trick?
try {
title = jsonDoc.getString("title_full");
} catch (JSONException e) {
log.info("no full title: " + docString);
}
{
"organizations": [],
"uuid": "d0adc516c9012113774557365f9847da99b228e7",
"thread": {
"site_full": "www.fark.com",
"main_image": "http://img.fark.net/images/cache/orig/5/51/fark_514Jh7VFpynQw4MyN2xcK1jwCxk.png?t=RQrnhq8EGZiUuElMitgLOQ&f=1488776400",
"site_section": "http://www.fark.com/discussion/",
"section_title": "FARK.com: Discussion links",
"url": "http://www.fark.com/comments/9500577/I-want-to-support-work-that-NY-Times-Washington-Post-are-doing-I-can-only-afford-one-subscription-Who-do-you-recommend-I-throw-my-support-to?cpp=1",
"country": "US",
"domain_rank": 3382,
"title": "(9500577) I want to support the work that the NY Times and Washington Post are doing. I can only afford one subscription. Who do you recommend I throw my support to?",
"performance_score": 0,
"site": "fark.com",
"participants_count": 31,
"title_full": "FARK.com: (9500577) I want to support the work that the NY Times and Washington Post are doing. I can only afford one subscription. Who do you recommend I throw my support to?",
"spam_score": 0.0,
"site_type": "discussions",
"published": "2017-03-03T12:00:00.000+02:00",
"replies_count": 2,
"uuid": "67213179a24931106e75cd588386bd30fb3bbdc8"
},
"author": "EbolaNYC",
"url": "http://www.fark.com/comments/9500577/I-want-to-support-work-that-NY-Times-Washington-Post-are-doing-I-can-only-afford-one-subscription-Who-do-you-recommend-I-throw-my-support-to?cpp=1#c107765048",
"ord_in_thread": 1,
"title": "",
"locations": [],
"entities": {
"persons": [],
"locations": [],
"organizations": []
},
"highlightText": "",
"language": "english",
"persons": [],
"text": "dionysusaur : Either the NY Post or the WA Times.\nOnly asshats read the NY Post.",
"external_links": [],
"published": "2017-03-03T15:58:00.000+02:00",
"crawled": "2017-03-03T17:05:26.049+02:00",
"highlightTitle": "",
"social": {
"gplus": {"shares": 0},
"pinterest": {"shares": 0},
"vk": {"shares": 0},
"linkedin": {"shares": 0},
"facebook": {"likes": 0, "shares": 0, "comments": 0},
"stumbledupon": {"shares": 0}
}
}
Your JSON seems like follows:
{
{
"main": {
"key": "value",
},
},
}
So, First fetch the main json and then the key.
Code should be like as follows:
String something = jsonDoc.get("main").get("key").toString();
There are two title values in your JSON, Do check which title you need before fetching.
After I formatted the json code, the problem becomes obvious:
title_full is only available inside the thread node, and a non-empty title is also only inside the thread node. So you'll first have to access the thread node and then access title and title_full inside that node.
Using the org.json library, you can access the fields like this:
String fullTitle = jsonDoc.getJSONObject("thread").getString("title_full");
If you take a look at the json you will see that the "title" and "title_full" fields are in the thread field.
So try reading that field and then parsing the filed into a new jsonObject and you should be able to get them.
Am a new bee to vaadin. I have to show the data from a JSON file (which is fetching from MySQL db) in Grid/Table(vaadin). I am able show the data in table if JSON in the below format.
[
{
"id": "ex-wardrobe",
"productId": "ex-wardrobe",
"name": "exWardrobe",
"desc": "Some description",
"dimension": "WxDxH 148\" X 24\" X 112\" ",
"category": "Bedroom",
"subcategory": "Wardrobe",
"categoryId": "bedroom",
"subcategoryId": "wardrobe",
"tags": "all, Space Design Bedroom, Space Details Wardrobe",
"designer": "hb",
"curr": "INR",
"popularity": "1",
"relevance": "1",
"shortlisted": "1",
"likes": "1",
"createDt": "",
"pageId": "ex-wardrobe",
"styleName": "Fresh",
"styleId": "cfresh",
"priceRange": "Premium",
"priceId": "premium",
"defaultPrice": "123",
"defaultMaterial": "MDF ",
"defaultFinish": "LAMINATE"
}
]
But, if i get JSON(data is related to same product) in the below format am unable to add data in table.
[
{
"id": "ex-wardrobe",
"productId": "ex-wardrobe",
"name": "exWardrobe",
"desc": "Some description",
"dimension": "WxDxH 148\" X 24\" X 112\" ",
"category": "Bedroom",
"subcategory": "Wardrobe",
"categoryId": "bedroom",
"subcategoryId": "wardrobe",
"tags": "all, Space Design Bedroom, Space Details Wardrobe",
"designer": "hb",
"curr": "INR",
"popularity": "1",
"relevance": "1",
"shortlisted": "1",
"likes": "1",
"createDt": "",
"pageId": "ex-wardrobe",
"styleName": "Fresh",
"styleId": "cfresh",
"priceRange": "Premium",
"priceId": "premium",
"defaultPrice": "123",
"defaultMaterial": "MDF ",
"defaultFinish": "LAMINATE",
"mf": [
{
"basePrice": "123",
"material": "MDF ",
"finish": "LAMINATE"
}
],
"images": [
"066___ex_WARDROBE_Dim.jpg",
"067___ex_WARDROBE_close_door.jpg",
"068___ex_DOVE_dim.jpg"
],
"components": [],
"accessories": []
}
]
This is the code which am using to show JSON data in table,
Table grid = new Table();
root.addComponent(grid);
grid.setStyleName("iso3166");
grid.setPageLength(6);
grid.setSizeFull();
grid.setSelectable(true);
grid.setMultiSelect(false);
grid.setImmediate(true);
grid.setColumnReorderingAllowed(true);
grid.setColumnCollapsingAllowed(true);
try {
JSONArray products = productsDataProvider.getCatalogs();
JsonContainer dataSource =
JsonContainer.Factory.newInstance(products.toString());
grid.setContainerDataSource(dataSource);
grid.setColumnReorderingAllowed(true);
grid.setWidth("98%");
grid.addStyleName(ChameleonTheme.TABLE_STRIPED);
} catch (IllegalArgumentException ignored) {
}
grid.setWidth("100%");
grid.setHeight("100%");
root.addComponent(grid);
Am stuck on this and i have sleepless night on this. Million tons of thanks in advance. I hope you GURU's can help me in this :)
Sorry not vaadin expert. See it first time and like it. I guess your problem are the arrays inside your object. I mean this:
"mf": [
{
"basePrice": "173881",
"material": "MDF ",
"finish": "LAMINATE"
}
],
"images": [
"066___ex_WARDROBE_Dim.jpg",
"067___ex_WARDROBE_close_door.jpg",
"068___ex_DOVE_dim.jpg"
],
"components": [],
"accessories": []
No idea how the component should display this. Have you tried it without mf, images, components and accessories?
You are using a very simple JSONContainer. As can be seen in the source code, this implementation does not support nested / compound elements and arrays.
First you have to ask yourself how these complex objects need to be displayed (UX), especially the "mf" field.
UPDATE
Simple compound objects (like "simpleCompound": {"name": "foo", number: 123}) can be shown in a table column (not supported by the JSONContainer you use, but similar functionality is available by the BeanItemContainer, so look there for how to implement this functionality).
The array fields are more problematic from a UX standpoint. Mostly this information is only shown on demand or in separate panels. The Vaadin Grid component offers the possibility to show a details view, see the wiki. Maybe that will fit your requirements.
Currently nested json data is not supported unless you create your own advance template for that. There is currently an online json container application demo that is used to test if the data is really json or json array but not nested. Then it displays that data in grid table. So you can use this to verify your data.
You can also get the application template with source code on github
Im requesting data from instagram api when I search for any tag. In return I get a massive chunk of json data corresponding to like 20 pictures. The response below is the chunk I used to generate my pojos online
{
"pagination": {
"next_max_tag_id": "1193052000552992097",
"deprecation_warning": "next_max_id and min_id are deprecated for this endpoint; use min_tag_id and max_tag_id instead",
"next_max_id": "1193052000552992097",
"next_min_id": "1193052554319844057",
"min_tag_id": "1193052554319844057",
"next_url": "https://api.instagram.com/v1/tags/cats/media/recent?access_token=631477962.1fb234f.f7c5cda97c7f4df983b1c764f066ed37&max_tag_id=1193052000552992097"
},
"meta": {
"code": 200
},
"data": [
{
"attribution": null,
"tags": [
"cats",
"caseworker",
"homestuck"
],
"type": "image",
"location": null,
"comments": {
"count": 0,
"data": []
},
"filter": "Normal",
"created_time": "1456442969",
"link": "https://www.instagram.com/p/BCOkvoim1LZ/",
"likes": {
"count": 0,
"data": []
},
"images": {
"low_resolution": {
"url": "https://scontent.cdninstagram.com/t51.2885-15/s320x320/e35/12729405_224148847934280_1450226662_n.jpg?ig_cache_key=MTE5MzA1MjU1NDMxOTg0NDA1Nw%3D%3D.2",
"width": 320,
"height": 320
},
"thumbnail": {
"url": "https://scontent.cdninstagram.com/t51.2885-15/s150x150/e35/12729405_224148847934280_1450226662_n.jpg?ig_cache_key=MTE5MzA1MjU1NDMxOTg0NDA1Nw%3D%3D.2",
"width": 150,
"height": 150
},
"standard_resolution": {
"url": "https://scontent.cdninstagram.com/t51.2885-15/s640x640/sh0.08/e35/12729405_224148847934280_1450226662_n.jpg?ig_cache_key=MTE5MzA1MjU1NDMxOTg0NDA1Nw%3D%3D.2",
"width": 640,
"height": 640
}
},
"users_in_photo": [],
"caption": {
"created_time": "1456442969",
"text": "Bitch! I'm fabulous! That's my case worker..she is obsessed with cats\n\n#cats #caseworker #homestuck",
"from": {
"username": "strider_inc",
"profile_picture": "https://scontent.cdninstagram.com/t51.2885-19/s150x150/12558836_953196128050469_1739102_a.jpg",
"id": "2322171747",
"full_name": "WE All 4EVER KAWAII TRASH GODS"
},
"id": "1193052563471815092"
},
"user_has_liked": false,
"id": "1193052554319844057_2322171747",
"user": {
"username": "strider_inc",
"profile_picture": "https://scontent.cdninstagram.com/t51.2885-19/s150x150/12558836_953196128050469_1739102_a.jpg",
"id": "2322171747",
"full_name": "WE All 4EVER KAWAII TRASH GODS"
}
}
So when I do that I get like 10-12 different pojo classes into which I should map this data. Now firstly...Im just trying that out and Im 100% Ill have some problem mapping them I mean gson will do it for me but i dont know if there are any more that I would need etc.
but most importantly my app only needs the low standard url pictures all the other information is useless for me.
Ofcourse, I know one way to do it which is to convert the whole thing into a string and parse the whole string through multiple times looking for key words etc and making images etc. I dont want to do that because its ugly. It works but I want a concise way of doing that at the same time without mapping completely.
Using Gson's JsonParser class, you can parse your JSON into a tree of JsonElements, and then extract just the data that you need.
For example, in order to print out all the low resolution URLs, you could use the following code:
String json = "...";
JsonParser parser = new JsonParser();
JsonObject object = parser.parse(json).getAsJsonObject();
JsonArray data = object.getAsJsonArray("data");
for (JsonElement element : data) {
JsonObject images = element.getAsJsonObject().getAsJsonObject("images");
JsonObject lowResolution = images.getAsJsonObject("low_resolution");
String url = lowResolution.getAsJsonPrimitive("url").getAsString();
System.out.println(url);
}
Using your example JSON, this would print:
https://scontent.cdninstagram.com/t51.2885-15/s320x320/e35/12729405_224148847934280_1450226662_n.jpg?ig_cache_key=MTE5MzA1MjU1NDMxOTg0NDA1Nw%3D%3D.2
I am developing first time in android and i have never used json data before. I will develop an application of event calendar of my university. We developed web version application in Django and we implement tastypie (restapi) so i need to use this json data for android mobile version. My json data is like this :
{
"meta": {
"limit": 20,
"next": null,
"offset": 0,
"previous": null,
"total_count": 5
},
"objects": [{
"Location": "Z011",
"Notes": "asdf",
"Title": "Literature Talking",
"id": 3,
"resource_uri": "/api/v1/Events/3/"
}, {
"Location": "Batı Kampüsü, Sinema Salonua",
"Notes": "sd",
"Title": "TARİHÇE KONFERANSLARI SERİSİ 25",
"id": 4,
"resource_uri": "/api/v1/Events/4/"
}, {
"Location": "in Campus",
"Notes": "afafdf",
"Title": "Self-Assessment Project",
"id": 5,
"resource_uri": "/api/v1/Events/5/"
}, {
"Location": "Kütüphane",
"Notes": "fs",
"Title": "51.Kütüphane Haftası",
"id": 6,
"resource_uri": "/api/v1/Events/6/"
}]
}
how can I parse this Json data in android studio?
Using below code you will be able to get Title and Location
JSONObject obj=new JSONObject(response);//This is response from webservice
String totalCount = obj.getJSONObject("meta").getString("total_count"); //for getting total_count
JSONArray json_array = obj.getJSONArray("objects");
for(int j=0;j<json_array.length();j++) {
String title = json_array.getJSONObject(j).getString("Title");
String location= json_array.getJSONObject(j).getString("Location");
}
Use this website to help you view the Json structure better
http://www.jsontree.com/
What you have is a Json Object since it starts and ends with curly braces.
For example if I had a Json as {"Id":"1"}
The Key is "Id" and the value is "1"
A Json object can have a Json inside the value as well(Which is your case)
And example is {"Id":{"Place1":"1", "Place2":"2"}}
So the Key is "Id" and it has the value "Place1":"1", "Place2":"2"
So the value is also a Json.
It can get a little messy with Jsons in Jsons.
Here is a good tutorial on parsing Json
http://www.tutorialspoint.com/android/android_json_parser.htm
Say I have a JSON array similar to the following:
[
{
"title": "This is a title",
"year": 2013,
"images": {
"image": "http://........jpg",
},
"ratings": {
"thumbsup": 1053,
"thumbsdown": 256
}
},
{
"title": "This is a title",
"year": 2013,
"images": {
"image": "http://........jpg",
},
"ratings": {
"thumbsup": 1053,
"thumbsdown": 256
}
}
]
And the required output is a JSON array like this:
[
{
"title": "This is a title",
"images": {
"image": "http://........jpg",
},
"ratings": {
"thumbsup": 1053,
}
},
{
"title": "This is a title",
"images": {
"image": "http://........jpg",
},
"ratings": {
"thumbsup": 1053,
}
}
]
Iv'e been researching and it's suggested that the most efficient way would be to parse it using the Jackson streaming API. This is for use on a PaaS with limited memory, so I wish to keep the memory usage to the bare minimum.
Is the best way to parse the JSON with Jackson Streaming API, and construct a new JSON array at the same time or simply remove the elements somehow?
I did something similiar with XML once. You can have the requestor tell you what fields you want to get back, and have it only emit those. In my case I had no control over the 3rd party axis xml view, but once I had the view, when I asked for things from it if it was already there I could give back just the pieces I was interested in. As a bonus, if you are marshalling or unmarshalling real java objects from the JSON after getting the json or XML you don't need to build the part of the object graph you don't care about.