Develop Reference

Trying to convert JSON data to a JSON array in Android Studio

Hello im trying to convert some JSON data into an array, I have dont it this way before but without objects
http://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/1.0_day.geojson
Here is the code that gets the data and trys to convert it
public JSONArray getQaukes()
{
String url = "http://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/1.0_day.geojson";
// Get HttpResponse Object from url.
// Get HttpEntity from Http Response Object
HttpEntity httpEntity = null;
try
{
DefaultHttpClient httpClient = new DefaultHttpClient(); // Default HttpClient
HttpGet httpGet = new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpGet);
httpEntity = httpResponse.getEntity();
} catch (ClientProtocolException e) {
// Signals error in http protocol
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// Convert HttpEntity into JSON Array
JSONArray jsonArray = null;
if (httpEntity != null) {
try {
String entityResponse = EntityUtils.toString(httpEntity);
Log.d("Entity Response : ", entityResponse);
jsonArray = new JSONArray(entityResponse);
} catch (JSONException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
return jsonArray;
}
This is what i get
http://pastebin.com/HVnx3gsq
Anyone know how I could find the correct way to do this?
Thanks

The result is a JSONObject not JSONArray.
Instead of JSONArray jsonArray = new JSONArray(entityResponse);
You should have JSONObject jObj = new JSONObject(entityResponse);

Edit: As an example, if you were to extract "features" Array, then you should do it like that:
//First of all - create JSON Object which you are going to parse (deserialize JSON string)
JSONObject jsonObj = new JSONObject(entityResponse);
// Extract JSON array from Object
JSONArray jsonArray = jsonObj.getJSONArray("features");
Your JSON string has many different elements, that is why you need to create JSON object, then extract arrays from it and so on. Until the very last token.
"type":"FeatureCollection",
"metadata":{
"generated":1452461493000,
"url":"http://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/1.0_day.geojson",
"title":"USGS Magnitude 1.0+ Earthquakes, Past Day",
"status":200,
"api":"1.1.0",
"count":128
},
"features":[
{
"type":"Feature",
"properties":{
"mag":2.07,
"place":"28km S of Gardnerville Ranchos, Nevada",
"time":1452460963440,
"updated":1452461071893,
"tz":-480,
"url":"http://earthquake.usgs.gov/earthquakes/eventpage/nc72578341",
"detail":"http://earthquake.usgs.gov/earthquakes/feed/v1.0/detail/nc72578341.geojson",
"felt":null,
"cdi":null,
"mmi":null,
"alert":null,
"status":"automatic",
"tsunami":0,
"sig":66,
"net":"nc",
"code":"72578341",
"ids":",nn00526227,nc72578341,",
"sources":",nn,nc,",
"types":",general-link,general-link,geoserve,nearby-cities,origin,phase-data,",
"nst":8,
"dmin":0.06765,
"rms":0.11,
"gap":197,
"magType":"md",
"type":"earthquake",
"title":"M 2.1 - 28km S of Gardnerville Ranchos, Nevada"
},
"geometry":{
"type":"Point",
"coordinates":[
-119.751503,
38.6351662,
-1.8
]
},
"id":"nc72578341"
},
{
"type":"Feature",
"properties":{
"mag":2.3,
In the extract above you have: "type" - JSON value, "metadata" - JSON Object, "features" - JSON Array and so on.
I recommend you looking into JSON syntax, so then you will be able to understand how to parse the data: http://www.w3schools.com/json/json_syntax.asp

Pass Class Object to MultiPart Entity in android

I have to work on an application where i need to send the class object as Parameter using Multipart Entity along with a file. I have checked that the Multipart addpart method doesn't accept an Object to post to Web Api.Below is the Code i have tried. Any Suggestions on how to pass the object would be great.
HttpPost post = BaseActivity.getHttpPost("MyURL");
MultipartEntity entity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE,"",Charset.defaultCharset());
try {
ServiceJobFileModel sjfm = new ServiceJobFileModel();
sjfm.setFileExtension(myfileextension);
sjfm.setCapturedDate(captdate);
sjfm.setFileName("/pathtofile/filename.extension");
File f = new File(sjmf.getFileName());
entity.addPart("file", new FileBody(f));
entity.addPart("serviceJobFileModel", sjfm); // Compiler Error
post.addHeader("Accept-Encoding", "gzip, deflate");
post.setEntity(entity);
} catch (UnsupportedEncodingException e) {
Log.v("encoding exception","E::: "+e);
e.printStackTrace();
}
The Web Api is developed in Dotnet which is why the windows mobile app has sent the parameters as
var parameters = new ServiceJobFileModel()
{
FileExtension = serviceJobFileModel.FileExtension,
CapturedDate = serviceJobFileModel.CapturedDate,
ServiceJobNumber = serviceJobFileModel.ServiceJobNumber
};
content.Add(new StreamContent(filestream), "file", Path.GetFileName(fileName));
content.Add(new ObjectContent<ServiceJobFileModel>(parameters, new JsonMediaTypeFormatter()), "serviceJobFileModel");

IMHO you should serialize your object in a text format like JSON or XML and then use a StringBody to send it.

Downloading a JSON Array from a URL in Android

I'm trying to download a JSON file in this format
[
{
"CRN":"10001",
"Course":"REG1"
},
{
"CRN":"10002",
"Course":"REG2"
}
]
I understand how to use a JSONArray class once it is created but I don't know how to create the JSONArray object from the file. If the URL location of the file were to be "www.test.com" how would I go about downloading it in background upon the launch of my application so as to not interfere with the launching of the app but not require the user to manually download it themselves.

You might want to check out this helpful library: Retrofit
It makes grabbing and parsing JSON data easy!

I think you should look for Android Web Service example. Where you can find info about
1.How to make a HTTP request to server (using URL eg. www.google.com)
2. How to handle Response from Server
3. How to parse JSON/XML response from Server etc.
Here is the Simple Tutorial I Found for you.
Android Web service for Log-in and Registration
Just go through step by step.
In the example we are making request to server for login and getting response then going ahead in app.
Here is the code snipp.
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url, List<NameValuePair> params) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "n");
}
is.close();
json = sb.toString();
Log.e("JSON", json);
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}

A good way to download the JSON file automatically, would be to launch an AsyncTask during your onCreate method of the home activity.
JSON files are nothing more than text files in a special format, so the could be easily downloaded as a response from a HttpURLConnection, and then be treated as a String.
A suggestion for parsing the JSON objets into Java objects would be the Jackson JSON Processor. You could use the class ObjectMapper of this library to automatically create the objects.
If you are planing to implement the server side by yourself, and you also need a library to send JSON objects, you could use Jersey on both server and client.

Android parse json from url and store it

Hi there i'm creating my first android app and i'm wanting to know what is the best and most efficient way of parsing a JSON Feed from a URL.Also Ideally i want to store it somewhere so i can keep going back to it in different parts of the app. I have looked everywhere and found lots of different ways of doing it and i'm not sure which to go for. In your opinion whats the best way of parsing json efficiently and easily?

I'd side with whatsthebeef on this one, grab the data and then serialize to disk.
The code below shows the first stage, grabbing and parsing your JSON into a JSON Object and saving to disk
// Create a new HTTP Client
DefaultHttpClient defaultClient = new DefaultHttpClient();
// Setup the get request
HttpGet httpGetRequest = new HttpGet("http://example.json");
// Execute the request in the client
HttpResponse httpResponse = defaultClient.execute(httpGetRequest);
// Grab the response
BufferedReader reader = new BufferedReader(new InputStreamReader(httpResponse.getEntity().getContent(), "UTF-8"));
String json = reader.readLine();
// Instantiate a JSON object from the request response
JSONObject jsonObject = new JSONObject(json);
// Save the JSONOvject
ObjectOutput out = new ObjectOutputStream(new FileOutputStream(new File(getCacheDir(),"")+"cacheFile.srl"));
out.writeObject( jsonObject );
out.close();
Once you have the JSONObject serialized and save to disk, you can load it back in any time using:
// Load in an object
ObjectInputStream in = new ObjectInputStream(new FileInputStream(new File(new File(getCacheDir(),"")+"cacheFile.srl")));
JSONObject jsonObject = (JSONObject) in.readObject();
in.close();

Your best bet is probably GSON
It's simple, very fast, easy to serialize and deserialize between json objects and POJO, customizable, although generally it's not necessary and it is set to appear in the ADK soon. In the meantime you can just import it into your app. There are other libraries out there but this is almost certainly the best place to start for someone new to android and json processing and for that matter just about everyone else.
If you want to persist you data so you don't have to download it every time you need it, you can deserialize your json into a java object (using GSON) and use ORMLite to simply push your objects into a sqlite database. Alternatively you can save your json objects to a file (perhaps in the cache directory)and then use GSON as the ORM.

This is pretty straightforward example using a listview to display the data. I use very similar code to display data but I have a custom adapter. If you are just using text and data it would work fine. If you want something more robust you can use lazy loader/image manager for images.

Since an http request is time consuming, using an async task will be the best idea. Otherwise the main thread may throw errors. The class shown below can do the download asynchronously
private class jsonLoad extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... urls) {
String response = "";
for (String url : urls) {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
try {
HttpResponse execute = client.execute(httpGet);
InputStream content = execute.getEntity().getContent();
BufferedReader buffer = new BufferedReader(new InputStreamReader(content));
String s = "";
while ((s = buffer.readLine()) != null) {
response += s;
}
} catch (Exception e) {
e.printStackTrace();
}
}
return response;
}
#Override
protected void onPostExecute(String result) {
// Instantiate a JSON object from the request response
try {
JSONObject jsonObject = new JSONObject(result);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
File file = new File(getApplicationContext().getFilesDir(),"nowList.cache");
try {
file.createNewFile();
FileOutputStream writer = openFileOutput(file.getName(), Context.MODE_PRIVATE);
writer.write(result);
writer.flush();
writer.close();
}
catch (IOException e) { e.printStackTrace(); return false; }
}
}
Unlike the other answer, here the downloaded json string itself is saved in file. So Serialization is not necessary
Now loading the json from url can be done by calling
jsonLoad jtask=new jsonLoad ();
jtask.doInBackground("http:www.json.com/urJsonFile.json");
this will save the contents to the file.
To open the saved json string
File file = new File(getApplicationContext().getFilesDir(),"nowList.cache");
StringBuilder text = new StringBuilder();
try {
BufferedReader br = new BufferedReader(new FileReader(file));
String line;
while ((line = br.readLine()) != null) {
text.append(line);
text.append('\n');
}
br.close();
}
catch (IOException e) {
//print log
}
JSONObject jsonObject = new JSONObject(text);

How to use JSON for inserting records into SQL database

Let's say I store a list of names , for eg: "abc","bcd","gdf"... in an array of Strings. I have an Android app that displays each of those values along with a checkbox. I need to convert my String array into a JSON String so that I can store it in a remote database. Right now I am working on localhost with a database created using SQL Server. I need to insert the JSON string values in the database using a web service , preferably SOAP
How should I do this ? Is there any other better way to do so ?
Here is my Android code.
Thanks

In my case this works fine,
JSONObject jsonObject = new JSONObject();
jsonObject.put("key1", value1);
jsonObject.put("key2", value2);
JSONArray jArrayParam = new JSONArray();
jArrayParam.put(jsonObject);
List<NameValuePair> nameValuePair = new ArrayList<NameValuePair>();
nameValuePair.add(new BasicNameValuePair("bulkdata",
jArrayParam.toString()));
Log.e("bulkdata", jArrayParam.toString());
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("yor remote database url");
httppost.addHeader("Content-Type", "application/x-www-form-urlencoded");
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs, HTTP.UTF_8));
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
// get response entity
HttpEntity entity = response.getEntity();
Try it. Thnx.

Well, I just tried to show you how to write the String array to JSONObject and JSONArray.
String arr[] = {"1","parth","present","30-82011","Mumbai"};
try {
JSONObject obj=new JSONObject();
obj.put("rollno",new Integer(arr[0]));
obj.put("status",arr[1]);
obj.put("date",arr[2]);
obj.put("place",arr[3]);
System.out.print(obj.toString(1));
JSONArray list = new JSONArray();
list.put(arr[0]);
list.put(arr[1]);
list.put(arr[2]);
list.put(arr[3]);
System.out.print(list.toString(1));
System.out.println("");
} catch (Exception e) {
e.printStackTrace();
}

var arr:String = com.adobe.serialization.json.JSON.encode(Obj);
var data_projects:Array = stmt.getResult().data;
var b_data:String = com.adobe.serialization.json.JSON.encode(data_projects);
var arr:String = com.adobe.serialization.json.JSON.encode(data_projects);
var arr1:Object = com.adobe.serialization.json.JSON.decode(b_data) as Array;
 for(var d:int=0;d<=data_projects.length-1;d++)
 
{
//Mapping properties of Proxy classes with actual fields
var bbb:Object = new Object;
data.MdId = arr1[d].MD_ID;
data.MdDevId=arr1[d].MD_DEVICE_ID;
data.MdRecId=arr1[d].MD_REC_ID;
data.MdPrjId= arr1[d].MD_PRJ_ID ;
data.MdMbcId = arr1[d].MD_MBC_ID;
data.MdMbcValue= arr1[d].MD_MBC_VALUE;
data.MdParentRecId= arr1[d].MD_MBC_ID;
//below is the create method on the WSDL
ws.Create(data);
}