Im trying to parse JSON and my code is not working with one URL and it works with other. I think its the coma in question but I did not sure so please look at my code and help.
I tried to replace coma with dot in loop, but what i get is JSON Exception. And when I change the URL, there is no exception. Confusing...
This is not working URL: http://api.hnb.hr/tecajn/v1
And this is one I tested and it works: https://newsapi.org/v2/top-headlines?country=us&category=business&apiKey=e402c76fc8584a1c81849179f1277a74
While changed the URL I also changed the data, so its not the problem in writing..I guess
Here is my code for coma replacement:
private String convertStreamToString(InputStream is) {
BufferedReader reader = new BufferedReader(new
InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line;
try {
while ((line = reader.readLine()) != null) {
String coma = line.replaceFirst(",",".");
sb.append(coma).append('\n');
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return sb.toString();
}
And the other part with URL and JSONArray:
#Override
protected Void doInBackground(Void... arg0) {
URLconnection urlConn = new URLconnection();
// Making a request to url and getting response
String url = "http://api.hnb.hr/tecajn/v1";
//.........connection.........
String response = urlConn.makeServiceCall(url);
Log.e(TAG, "Response from url: " + response);
if (response != null) {
try {
JSONObject jsonObj = new JSONObject(response);
// Getting JSON Array node
arr = jsonObj.getJSONArray("values");
for (int i = 0; i < article.length(); i++) {
JSONObject c = arr.getJSONObject(i);
header = c.getString("Valuta");
}
} catch (final JSONException e) {
Log.e(TAG, "Json parsing error.");
runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(getApplicationContext(),
"Json parsing error: 216",
Toast.LENGTH_LONG).show();
}
});
}
Commas aren't the issue. It's the very first character. One is a square bracket and the other is a curly one.
You therefore need to parse the first response as an Array rather than an Object
new JSONArray(response);
That being said, you therefore cannot use the same methods for both URLs
I've been following a tutorial which provided an example website to use in the json request, however when i put in my own website to scrape data from, nothing happens.
Here is my code;
private TextView tvData;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tvData = (TextView) findViewById(R.id.tvJsonItem);
new JSONTask().execute("http://jsonparsing.parseapp.com/jsonData/moviesDemoItem.txt");
}
public class JSONTask extends AsyncTask<String,String, String>{
#Override
protected String doInBackground(String ... params) {
HttpURLConnection connection = null;
BufferedReader reader = null;
try {
URL url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
String finalJson = buffer.toString();
JSONObject parentObject = new JSONObject(finalJson);
JSONArray parentArray = parentObject.getJSONArray("movies");
JSONObject finalObject = parentArray.getJSONObject(0);
String ChampionName = finalObject.getString("movie");
String mostGames = finalObject.getString("year");
return ChampionName + mostGames;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
#Override
protected void onPostExecute(String result){
super.onPostExecute(result);
tvData.setText(result);
}
}
}
Screen of when it works on left and screen when it doesnt work on right.
So yeah, this is what i know i have to change
new JSONTask().execute("http://api.champion.gg/champion/Ekko");
and
JSONObject parentObject = new JSONObject(finalJson);
JSONArray parentArray = parentObject.getJSONArray("WHAT DO I PUT HERE");
JSONObject finalObject = parentArray.getJSONObject(0);
String ChampionName = finalObject.getString("WHAT DO I PUT HERE");
String mostGames = finalObject.getString("WHAT DO I PUT HERE");
From this URL - http://api.champion.gg/champion/Ekko/ , i want to get lets say the first two fields "key":"Ekko","role":"Top", so if anyone could give me a hand, that would be great!
According to the JSON returned form your link http://api.champion.gg/champion/Ekko/
You have to start to parse your string response as JSONArray
JSONArray parentObject = new JSONArray(finalJson);
then start to loop through this array to get JSONObject
JSONObject jsonObject = parentObject.getJSONObject(yourLoopIndex);
Inside each JSONObject you can get any value. by using the key in the original JSON string.
Everything seems to be fine except for the JSON exception error.
Here it is specifically: org.json.JSONException:
Value username of type `java.lang.String` cannot be converted to `JSONObject`.
There are a number of other flags that I can check in logcat and everything seems pretty good except that. I think the problem is that I need to convert the String encodedStr into a JSON object and return it to ASYNC TASK.
private class AsyncDataClass extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... params) {
//Use HashMap, it works similar to NameValuePair
Map<String, String> dataToSend = new HashMap<>();
dataToSend.put("username", params[1]);
dataToSend.put("password", params[2]);
//Server Communication part - it's relatively long but uses standard methods
//Encoded String - we will have to encode string by our custom method (Very easy)
String encodedStr = getEncodedData(dataToSend);
//Will be used if we want to read some data from server
BufferedReader reader = null;
//Connection Handling
try {
//Converting address String to URL
URL url = new URL(serverUrl);
//Opening the connection (Not setting or using CONNECTION_TIMEOUT)
HttpURLConnection con = (HttpURLConnection) url.openConnection();
//Post Method
con.setRequestMethod("POST");
//To enable inputting values using POST method
//(Basically, after this we can write the dataToSend to the body of POST method)
con.setDoOutput(true);
OutputStreamWriter writer = new OutputStreamWriter(con.getOutputStream());
//Writing dataToSend to outputstreamwriter
writer.write(encodedStr);
//Sending the data to the server - This much is enough to send data to server
//But to read the response of the server, you will have to implement the procedure below
writer.flush();
//Data Read Procedure - Basically reading the data comming line by line
StringBuilder sb = new StringBuilder();
reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
String line;
while ((line = reader.readLine()) != null) { //Read till there is something available
sb.append(line + "\n"); //Reading and saving line by line - not all at once
}
line = sb.toString();//Saving complete data received in string, you can do it differently
//Just check to the values received in Logcat
Log.i("custom_check", "The values received in the store part are as follows:");
Log.i("custom_check", line);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close(); //Closing the
} catch (IOException e) {
e.printStackTrace();
}
}
}
//Same return null, but if you want to return the read string (stored in line)
//then change the parameters of AsyncTask and return that type, by converting
//the string - to say JSON or user in your case
**strong text**return encodedStr;**strong text**
**strong text**HERE IS THE PROBLEM I BELIEVE.
}
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
System.out.println("Resulted Value: " + result);
if (result.equals("") || result == null) {
Toast.makeText(MainActivity.this, "Server connection failed", Toast.LENGTH_LONG).show();
return;
}
int jsonResult = returnParsedJsonObject(result);
if (jsonResult == 0) {
Toast.makeText(MainActivity.this, "Invalid username or password", Toast.LENGTH_LONG).show();
return;
}
if (jsonResult == 1) {
Intent intent = new Intent(MainActivity.this, LoginActivity.class);
intent.putExtra("USERNAME", enteredUsername);
intent.putExtra("MESSAGE", "You have been successfully login");
startActivity(intent);
}
}
private int returnParsedJsonObject(String result) {
JSONObject resultObject = null;
int returnedResult = 0;
try {
resultObject = new JSONObject(result);
returnedResult = resultObject.getInt("success");
} catch (JSONException e) {
e.printStackTrace();
}
return returnedResult;
}
}
private StringBuilder inputStreamToString(InputStream is) {
String rLine = "";
StringBuilder answer = new StringBuilder();
BufferedReader br = new BufferedReader(new InputStreamReader(is));
try {
while ((rLine = br.readLine()) != null) {
answer.append(rLine);
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return answer;
}
//************getEncodedData*****************//
private String getEncodedData(Map<String,String> data) {
StringBuilder sb = new StringBuilder();
for(String key : data.keySet()) {
String value = null;
try {
value = URLEncoder.encode(data.get(key), "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
if(sb.length()>0)
sb.append("&");
sb.append(key + "=" + value);
}
return sb.toString();
}`enter code here`
I am developing an android application in which first I am sending request to Web service and getting the response status in 0 or 1 format if I get the response as 1 then complete JSON file is loaded.
My question is I want to make an offline app for which I want to download the JSON data from one activity and read that data in different activity with listview displaying title of every downloaded JSON file. After clicking the listview item, JSON data is displayed. And some of the JSON data items contains URL of images I also want to download them and display them in another activity.
I also want to encrypt the downloaded JSON data. Please Help me.
For reference I have attached the JSON file format.
{"test_time":7200,"time_taken":"0","time_left":"7200","score":null,"easy_score":null,"medium_score":null,"hard_score":null,"status":"n","sections":[{"section_id":"196498","section_name":"Reasoning Aptitude","section_no":1,"total_questions":"40","total_minutes":"24","questions":[{"question_id":"61562","question":{"1":{"text":"In a certain code GRANT is written as UOBSH and PRIDE is written as FEJSQ. How is SOLD written in that code?","image":"","imgHeight":"","imgWidth":""}},"correct_ans":{"1":{"text":"EMPT","image":"","imgHeight":"","imgWidth":""}},"rightOption":[],"rightOptionID":"246408","rightOptionNo":"2","anwer_explaination":{"1":{"text":"","image":"http://abc.com/testengine/images/questions/bankpower/image1.Jpeg","imgHeight":304,"imgWidth":212},"2":{"text":" ","image":"","imgHeight":"","imgWidth":""}},"question_time_taken":"10","marked":"0","skipped":"0","answer_id":"1395795","option_choose":"246407","question_status":1,"options":[{"OptionId":"246406","OptionDesc":{"1":{"text":"EPMT","image":"","imgHeight":"","imgWidth":""}}},{"OptionId":"246407","OptionDesc":{"1":{"text":"TPME","image":"","imgHeight":"","imgWidth":""}}},{"OptionId":"246408","OptionDesc":{"1":{"text":"EMPT","image":"","imgHeight":"","imgWidth":""}}},{"OptionId":"246409","OptionDesc":{"1":{"text":"CKNR","image":"","imgHeight":"","imgWidth":""}}},{"OptionId":"246410","OptionDesc":{"1":{"text":"ETPM","image":"","imgHeight":"","imgWidth":""}}}]},{"question_id":"61563","question":{"1":{"text":"Four of the following five are alike in a certain way and so form a group. Which is the one that does not belong to that group?","image":"","imgHeight":"","imgWidth":""}},"correct_ans":{"1":{"text":"27","image":"","imgHeight":"","imgWidth":""}},"rightOption":[],"rightOptionID":"246414","rightOptionNo":"3","anwer_explaination":{"1":{"text":"Mouse is odd rest are use for storage.","image":"","imgHeight":"","imgWidth":""}},"question_time_taken":"0","marked":"0","skipped":"1","answer_id":"","option_choose":"","question_status":3,"options":[{"OptionId":"246411","OptionDesc":{"1":{"text":"19","image":"","imgHeight":"","imgWidth":""}}},{"OptionId":"246412","OptionDesc":{"1":{"text":"17","image":"","imgHeight":"","imgWidth":""}}},{"OptionId":"246413","OptionDesc":{"1":{"text":"13","image":"","imgHeight":"","imgWidth":""}}},{"OptionId":"246414","OptionDesc":{"1":{"text":"27","image":"","imgHeight":"","imgWidth":""}}},{"OptionId":"246415","OptionDesc":{"1":{"text":"37","image":"","imgHeight":"","imgWidth":""}}}]}
parse all the data using the parser detailed in that link
http://www.androidhive.info/2012/01/android-json-parsing-tutorial/
then Write all the data into a file using the method below , this way ur data is downloaded and saved as a file
public void appendData(String text)
{
File myFile = new File("sdcard/myfile.file");
if (!myFile.exists())
{
try
{
myFile.createNewFile();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
try
{
//BufferedWriter for performance, true to set append to file flag
BufferedWriter buf = new BufferedWriter(new FileWriter(myFile, true));
buf.append(text);
buf.newLine();
buf.close();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
You need to do something like this:
private class PrepareMapTask extends AsyncTask<String, Integer, Boolean>
{
// Initialize with invalid value
private int mPrepareResult = -1;
private String mJsonString = null;
protected Boolean doInBackground(String... urls)
{
mJsonString = downloadFileFromInternet(urls[0]);
if(mJsonString == null /*|| mJsonString.isEmpty()*/)
return false;
JSONObject jObject = null;
try {
jObject = new JSONObject(mJsonString);
JSONArray jsonImageArray = jObject.getJSONArray("imageTarget");
JSONArray jsonUrlArray = jObject.getJSONArray("videoUrls");
JSONArray jsonVideoOrUrlArray = jObject.getJSONArray("videoOrUrl");
if (jsonImageArray == null || jsonUrlArray == null)
return false;
for (int i = 0; i<jsonImageArray.length(); i++){
mapTargetUrl.put(jsonImageArray.get(i).toString(), jsonUrlArray.get(i).toString());
mVideoOrUrl.add(jsonVideoOrUrlArray.get(i).toString());
}
} catch (JSONException e) {
e.printStackTrace();
return false;
}
return true;
}
protected void onPostExecute(Boolean result)
{
}
private String downloadFileFromInternet(String url)
{
if(url == null /*|| url.isEmpty() == true*/)
new IllegalArgumentException("url is empty/null");
StringBuilder sb = new StringBuilder();
InputStream inStream = null;
try
{
url = urlEncode(url);
URL link = new URL(url);
inStream = link.openStream();
int i;
int total = 0;
byte[] buffer = new byte[8 * 1024];
while((i=inStream.read(buffer)) != -1)
{
if(total >= (1024 * 1024))
{
return "";
}
total += i;
sb.append(new String(buffer,0,i));
}
}catch(Exception e )
{
e.printStackTrace();
return null;
}catch(OutOfMemoryError e)
{
e.printStackTrace();
return null;
}
return sb.toString();
}
private String urlEncode(String url)
{
if(url == null /*|| url.isEmpty() == true*/)
return null;
url = url.replace("[","");
url = url.replace("]","");
url = url.replaceAll(" ","%20");
return url;
}
}
Take the data structures as per your json and modify the code.
try {
DefaultHttpClient httpclient = new DefaultHttpClient();
HttpPost httpPostRequest = new HttpPost(URL);
// Set HTTP parameters
/*StringEntity se;
se = new StringEntity(jsonObjSend.toString());*/
jsonObjSend.length();
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(jsonObjSend.length());
nameValuePairs.add(new BasicNameValuePair("data", jsonObjSend.toString()));
// Log.i("jsonObjSend.toString()","jsonObjSend.toString()"+jsonObjSend.toString());
Log.i("HTTPPOST","URL: "+URL);
Log.i("HTTPPOST","Request: "+jsonObjSend.toString());
UrlEncodedFormEntity en=new UrlEncodedFormEntity(nameValuePairs);
en.getContent();
httpPostRequest.getParams().setParameter("http.socket.timeout", new Integer(600000));
httpPostRequest.setEntity(en);
long t = System.currentTimeMillis();
HttpResponse response = (HttpResponse) httpclient.execute(httpPostRequest);
Log.i(TAG, "HTTPResponse received in [" + (System.currentTimeMillis()-t) + "ms]");
Log.i(TAG, httpPostRequest.getRequestLine().getProtocolVersion().toString());
responses = convertEntityToString(response.getEntity(), "UTF-8");
Log.i("HTTPPOST","Responce: "+responses);
Log.i("HTTPPOST","******************");
//Log.i("Encoding",response.getEntity().getContentEncoding().getName());
if (response.equalsIgnoreCase("")) {
webresponse = 1;
} else {
webresponse = 0;
}
} catch (IOException e) {
h.post(new Runnable() {
#Override
public void run() {
pd.dismiss();
AlertNullWebserviceResponce();
}
});
e.printStackTrace();
}
I am currently parsing through reddit.com/.json with Google Gson and having some trouble. After doing some research I found a way to parse through json with Gson without making a lot of classes. I am using this method. Here is my code so far:
import java.io.*;
import java.net.*;
import com.google.gson.*;
public class Subreddits {
public static void main(String[] args) {
URL u = null;
try {
u = new URL("http://www.reddit.com/.json");
} catch (MalformedURLException e) {
e.printStackTrace();
}
URLConnection yc = null;
try {
yc = u.openConnection();
} catch (IOException e) {
e.printStackTrace();
}
BufferedReader in = null;
try {
in = new BufferedReader(new InputStreamReader(yc.getInputStream()));
} catch (IOException e) {
e.printStackTrace();
}
String json = null;
StringBuilder sb = new StringBuilder();
try {
while ((json = in.readLine()) != null){
sb.append(json);
}
} catch (IOException e) {
e.printStackTrace();
}
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
json = sb.toString();//String of json
System.out.println(json);
//I want to get [data][children][data][subreddit]
JsonParser parser = new JsonParser();
JsonObject rootObj = parser.parse(json).getAsJsonObject();
JsonObject locObj = rootObj.getAsJsonObject("data").getAsJsonObject("children").getAsJsonObject("data");
String subreddit = locObj.get("subreddit").getAsString();
System.out.println(subreddit);
}
}
You are trying to get the element "children" as a JsonObject, but it is a JsonArray because it is surrounded by [ ]...
Try something like this:
JsonParser parser = new JsonParser();
JsonObject rootObj = parser.parse(json).getAsJsonObject();
//Here is the change
JsonObject locObj = rootObj
.getAsJsonObject("data")
.getAsJsonArray("children")
.get(0)
.getAsJsonObject()
.getAsJsonObject("data");
String subreddit = locObj.get("subreddit").getAsString();
Note: I assume that you only want to get the data of the first element of the "children" array, since it seems that it is what you want looking at your code and mainly looking at this other question of yours.
The children object returns an Array that you must iterate.
public static void main(String[] args) {
URL u = null;
try {
u = new URL("http://www.reddit.com/.json");
} catch (MalformedURLException e) {
e.printStackTrace();
}
URLConnection yc = null;
try {
yc = u.openConnection();
} catch (IOException e) {
e.printStackTrace();
}
BufferedReader in = null;
try {
in = new BufferedReader(new InputStreamReader(yc.getInputStream()));
} catch (IOException e) {
e.printStackTrace();
}
String json = null;
StringBuilder sb = new StringBuilder();
try {
while ((json = in.readLine()) != null) {
sb.append(json);
}
} catch (IOException e) {
e.printStackTrace();
}
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
json = sb.toString();// String of json
System.out.println(json);
// I want to get [data][children][data][subreddit]
JsonParser parser = new JsonParser();
JsonObject rootObj = parser.parse(json).getAsJsonObject();
JsonArray locObj = rootObj.getAsJsonObject("data").getAsJsonArray("children");
/* Iterating children object */
Iterator<JsonElement> iterator = locObj.iterator();
while(iterator.hasNext()){
JsonElement element = iterator.next();
JsonElement subreddit = element.getAsJsonObject().getAsJsonObject("data").get("subreddit");
System.out.println(subreddit.getAsString());
}
}
You don't need to create try..catch block for every expression that can throw an exception.
JsonParser.parse() method accepts Reader (e.g. InpustStreamReader) instance so you don't have to read JSON on your own.
root[data][children] is an array of objects so you'll have to iterate over them in order to gain access to individual objects.
I believe you want to read all [subredit]s into some sort of collection, Set I pressume?
public static void main(String[] args) {
try {
Set<String> subreddits = new HashSet<>();
URL url = new URL("http://www.reddit.com/.json");
JsonParser parser = new JsonParser();
JsonObject root = parser.parse(new InputStreamReader(url.openConnection().getInputStream())).getAsJsonObject();
JsonArray children = root.getAsJsonObject("data").getAsJsonArray("children");
for (int i = 0; i < children.size(); i++) {
String subreddit = children.get(i).getAsJsonObject().getAsJsonObject("data").get("subreddit").getAsString();
subreddits.add(subreddit);
}
System.out.println(subreddits);
} catch (IOException e) {
e.printStackTrace();
}
}
This code returns:
[IAmA, worldnews, technology, news, todayilearned, gaming, AskReddit, movies, videos, funny, bestof, science, WTF, politics, aww, pics, atheism, Music, AdviceAnimals]