I want to fetch json data from this link: link
& here is my code for that:
private static String url = "https://graph.facebook.com/fql?q=SELECT%20url,%20normalized_url,%20share_count,%20like_count,%20comment_count,%20total_count,%20commentsbox_count,%20comments_fbid,%20click_count%20FROM%20link_stat%20WHERE%20url=%27https://www.facebook.com/BillionHands%27";
// JSON Node names
private static final String TAG_DATA = "data";
private static final String TAG_SHARE = "share_count";
private static final String TAG_LIKE = "like_count";
private TextView LikeTv;
public String like;
JSONArray data = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_about_us);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
try {
// Getting Array of Contacts
data = json.getJSONArray(TAG_DATA);
JSONObject c = data.getJSONObject(0);
// Storing each json item in variable
String share = c.getString(TAG_SHARE);
like = c.getString(TAG_LIKE);
Log.i("Like Count",like);
} catch (JSONException e) {
e.printStackTrace();
}
LikeTv = (TextView) findViewById(R.id.tvLike);
LikeTv.setText(like);
Now I am getting "JSONException: no value for data" Please help... whats wrong in my code..
Well....
I got your problem solution...
The method you wrote getJSONFromUrl()..
I am sure it contains HttpPost object..
change that to HttpGet and it will start working...
EDIT
Here is the code I tried with
public class MainActivity extends Activity {
private static String url = "https://graph.facebook.com/fql?q=SELECT%20url,%20normalized_url,%20share_count,%20like_count,%20comment_count,%20total_count,%20commentsbox_count,%20comments_fbid,%20click_count%20FROM%20link_stat%20WHERE%20url=%27https://www.facebook.com/BillionHands%27";
// JSON Node names
private static final String TAG_DATA = "data";
private static final String TAG_SHARE = "share_count";
private static final String TAG_LIKE = "like_count";
private TextView LikeTv;
public String like;
JSONArray data = null;
#SuppressLint("NewApi")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONfromURL(url);
try {
// Getting Array of Contacts
Log.d("JSON ","DATA "+json);
data = json.getJSONArray(TAG_DATA);
JSONObject c = data.getJSONObject(0);
// Storing each json item in variable
String share = c.getString(TAG_SHARE);
like = c.getString(TAG_LIKE);
Log.i("Like Count",like);
} catch (JSONException e) {
e.printStackTrace();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
class JSONParser
{
public JSONObject getJSONfromURL(String url) {
InputStream is = null;
String result = "";
JSONObject jArray = null;
// http post
try {
HttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet(url);
HttpResponse response = httpclient.execute(httpget);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection " + e.toString());
}
// convert response to string
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();
result = sb.toString();
} catch (Exception e) {
Log.e("log_tag get data string ",
"Error converting result " + e.toString());
}
try {
jArray = new JSONObject(result);
} catch (JSONException e) {
Log.e("log_tag create object ",
"Error parsing data " + e.toString());
}
return jArray;
}
}
The "data" element in your JSON isn't an array, it is a JSONobject. So instead of:
JSONArray data = json.getJSONArray(TAG_DATA);
Try this:
JSONObject data = json.getJSONObject(TAG_DATA);
From the JSONObject, you can get items like TAG_SHARE and TAG_LIKE.
Good luck!
Related
This question already has answers here:
How to parse JSON in Java
(36 answers)
Closed 4 years ago.
How do I parse a JSON feed in Android?
Android has all the tools you need to parse json built-in. Example follows, no need for GSON or anything like that.
Get your JSON:
Assume you have a json string
String result = "{\"someKey\":\"someValue\"}";
Create a JSONObject:
JSONObject jObject = new JSONObject(result);
If your json string is an array, e.g.:
String result = "[{\"someKey\":\"someValue\"}]"
then you should use JSONArray as demonstrated below and not JSONObject
To get a specific string
String aJsonString = jObject.getString("STRINGNAME");
To get a specific boolean
boolean aJsonBoolean = jObject.getBoolean("BOOLEANNAME");
To get a specific integer
int aJsonInteger = jObject.getInt("INTEGERNAME");
To get a specific long
long aJsonLong = jObject.getLong("LONGNAME");
To get a specific double
double aJsonDouble = jObject.getDouble("DOUBLENAME");
To get a specific JSONArray:
JSONArray jArray = jObject.getJSONArray("ARRAYNAME");
To get the items from the array
for (int i=0; i < jArray.length(); i++)
{
try {
JSONObject oneObject = jArray.getJSONObject(i);
// Pulling items from the array
String oneObjectsItem = oneObject.getString("STRINGNAMEinTHEarray");
String oneObjectsItem2 = oneObject.getString("anotherSTRINGNAMEINtheARRAY");
} catch (JSONException e) {
// Oops
}
}
Writing JSON Parser Class
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
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();
} 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;
}
}
Parsing JSON Data
Once you created parser class next thing is to know how to use that class. Below i am explaining how to parse the json (taken in this example) using the parser class.
2.1. Store all these node names in variables: In the contacts json we have items like name, email, address, gender and phone numbers. So first thing is to store all these node names in variables. Open your main activity class and declare store all node names in static variables.
// url to make request
private static String url = "http://api.9android.net/contacts";
// JSON Node names
private static final String TAG_CONTACTS = "contacts";
private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL = "email";
private static final String TAG_ADDRESS = "address";
private static final String TAG_GENDER = "gender";
private static final String TAG_PHONE = "phone";
private static final String TAG_PHONE_MOBILE = "mobile";
private static final String TAG_PHONE_HOME = "home";
private static final String TAG_PHONE_OFFICE = "office";
// contacts JSONArray
JSONArray contacts = null;
2.2. Use parser class to get JSONObject and looping through each json item. Below i am creating an instance of JSONParser class and using for loop i am looping through each json item and finally storing each json data in variable.
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
try {
// Getting Array of Contacts
contacts = json.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for(int i = 0; i < contacts.length(); i++){
JSONObject c = contacts.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
String address = c.getString(TAG_ADDRESS);
String gender = c.getString(TAG_GENDER);
// Phone number is agin JSON Object
JSONObject phone = c.getJSONObject(TAG_PHONE);
String mobile = phone.getString(TAG_PHONE_MOBILE);
String home = phone.getString(TAG_PHONE_HOME);
String office = phone.getString(TAG_PHONE_OFFICE);
}
} catch (JSONException e) {
e.printStackTrace();
}
I've coded up a simple example for you and annotated the source. The example shows how to grab live json and parse into a JSONObject for detail extraction:
try{
// 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);
} catch(Exception e){
// In your production code handle any errors and catch the individual exceptions
e.printStackTrace();
}
Once you have your JSONObject refer to the SDK for details on how to extract the data you require.
This question already has answers here:
How to parse JSON in Java
(36 answers)
Closed 4 years ago.
How do I parse a JSON feed in Android?
Android has all the tools you need to parse json built-in. Example follows, no need for GSON or anything like that.
Get your JSON:
Assume you have a json string
String result = "{\"someKey\":\"someValue\"}";
Create a JSONObject:
JSONObject jObject = new JSONObject(result);
If your json string is an array, e.g.:
String result = "[{\"someKey\":\"someValue\"}]"
then you should use JSONArray as demonstrated below and not JSONObject
To get a specific string
String aJsonString = jObject.getString("STRINGNAME");
To get a specific boolean
boolean aJsonBoolean = jObject.getBoolean("BOOLEANNAME");
To get a specific integer
int aJsonInteger = jObject.getInt("INTEGERNAME");
To get a specific long
long aJsonLong = jObject.getLong("LONGNAME");
To get a specific double
double aJsonDouble = jObject.getDouble("DOUBLENAME");
To get a specific JSONArray:
JSONArray jArray = jObject.getJSONArray("ARRAYNAME");
To get the items from the array
for (int i=0; i < jArray.length(); i++)
{
try {
JSONObject oneObject = jArray.getJSONObject(i);
// Pulling items from the array
String oneObjectsItem = oneObject.getString("STRINGNAMEinTHEarray");
String oneObjectsItem2 = oneObject.getString("anotherSTRINGNAMEINtheARRAY");
} catch (JSONException e) {
// Oops
}
}
Writing JSON Parser Class
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
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();
} 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;
}
}
Parsing JSON Data
Once you created parser class next thing is to know how to use that class. Below i am explaining how to parse the json (taken in this example) using the parser class.
2.1. Store all these node names in variables: In the contacts json we have items like name, email, address, gender and phone numbers. So first thing is to store all these node names in variables. Open your main activity class and declare store all node names in static variables.
// url to make request
private static String url = "http://api.9android.net/contacts";
// JSON Node names
private static final String TAG_CONTACTS = "contacts";
private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL = "email";
private static final String TAG_ADDRESS = "address";
private static final String TAG_GENDER = "gender";
private static final String TAG_PHONE = "phone";
private static final String TAG_PHONE_MOBILE = "mobile";
private static final String TAG_PHONE_HOME = "home";
private static final String TAG_PHONE_OFFICE = "office";
// contacts JSONArray
JSONArray contacts = null;
2.2. Use parser class to get JSONObject and looping through each json item. Below i am creating an instance of JSONParser class and using for loop i am looping through each json item and finally storing each json data in variable.
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
try {
// Getting Array of Contacts
contacts = json.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for(int i = 0; i < contacts.length(); i++){
JSONObject c = contacts.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
String address = c.getString(TAG_ADDRESS);
String gender = c.getString(TAG_GENDER);
// Phone number is agin JSON Object
JSONObject phone = c.getJSONObject(TAG_PHONE);
String mobile = phone.getString(TAG_PHONE_MOBILE);
String home = phone.getString(TAG_PHONE_HOME);
String office = phone.getString(TAG_PHONE_OFFICE);
}
} catch (JSONException e) {
e.printStackTrace();
}
I've coded up a simple example for you and annotated the source. The example shows how to grab live json and parse into a JSONObject for detail extraction:
try{
// 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);
} catch(Exception e){
// In your production code handle any errors and catch the individual exceptions
e.printStackTrace();
}
Once you have your JSONObject refer to the SDK for details on how to extract the data you require.
This question already has answers here:
How to parse JSON in Java
(36 answers)
Closed 4 years ago.
How do I parse a JSON feed in Android?
Android has all the tools you need to parse json built-in. Example follows, no need for GSON or anything like that.
Get your JSON:
Assume you have a json string
String result = "{\"someKey\":\"someValue\"}";
Create a JSONObject:
JSONObject jObject = new JSONObject(result);
If your json string is an array, e.g.:
String result = "[{\"someKey\":\"someValue\"}]"
then you should use JSONArray as demonstrated below and not JSONObject
To get a specific string
String aJsonString = jObject.getString("STRINGNAME");
To get a specific boolean
boolean aJsonBoolean = jObject.getBoolean("BOOLEANNAME");
To get a specific integer
int aJsonInteger = jObject.getInt("INTEGERNAME");
To get a specific long
long aJsonLong = jObject.getLong("LONGNAME");
To get a specific double
double aJsonDouble = jObject.getDouble("DOUBLENAME");
To get a specific JSONArray:
JSONArray jArray = jObject.getJSONArray("ARRAYNAME");
To get the items from the array
for (int i=0; i < jArray.length(); i++)
{
try {
JSONObject oneObject = jArray.getJSONObject(i);
// Pulling items from the array
String oneObjectsItem = oneObject.getString("STRINGNAMEinTHEarray");
String oneObjectsItem2 = oneObject.getString("anotherSTRINGNAMEINtheARRAY");
} catch (JSONException e) {
// Oops
}
}
Writing JSON Parser Class
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
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();
} 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;
}
}
Parsing JSON Data
Once you created parser class next thing is to know how to use that class. Below i am explaining how to parse the json (taken in this example) using the parser class.
2.1. Store all these node names in variables: In the contacts json we have items like name, email, address, gender and phone numbers. So first thing is to store all these node names in variables. Open your main activity class and declare store all node names in static variables.
// url to make request
private static String url = "http://api.9android.net/contacts";
// JSON Node names
private static final String TAG_CONTACTS = "contacts";
private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL = "email";
private static final String TAG_ADDRESS = "address";
private static final String TAG_GENDER = "gender";
private static final String TAG_PHONE = "phone";
private static final String TAG_PHONE_MOBILE = "mobile";
private static final String TAG_PHONE_HOME = "home";
private static final String TAG_PHONE_OFFICE = "office";
// contacts JSONArray
JSONArray contacts = null;
2.2. Use parser class to get JSONObject and looping through each json item. Below i am creating an instance of JSONParser class and using for loop i am looping through each json item and finally storing each json data in variable.
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
try {
// Getting Array of Contacts
contacts = json.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for(int i = 0; i < contacts.length(); i++){
JSONObject c = contacts.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
String address = c.getString(TAG_ADDRESS);
String gender = c.getString(TAG_GENDER);
// Phone number is agin JSON Object
JSONObject phone = c.getJSONObject(TAG_PHONE);
String mobile = phone.getString(TAG_PHONE_MOBILE);
String home = phone.getString(TAG_PHONE_HOME);
String office = phone.getString(TAG_PHONE_OFFICE);
}
} catch (JSONException e) {
e.printStackTrace();
}
I've coded up a simple example for you and annotated the source. The example shows how to grab live json and parse into a JSONObject for detail extraction:
try{
// 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);
} catch(Exception e){
// In your production code handle any errors and catch the individual exceptions
e.printStackTrace();
}
Once you have your JSONObject refer to the SDK for details on how to extract the data you require.
This question already has answers here:
How to parse JSON in Java
(36 answers)
Closed 4 years ago.
How do I parse a JSON feed in Android?
Android has all the tools you need to parse json built-in. Example follows, no need for GSON or anything like that.
Get your JSON:
Assume you have a json string
String result = "{\"someKey\":\"someValue\"}";
Create a JSONObject:
JSONObject jObject = new JSONObject(result);
If your json string is an array, e.g.:
String result = "[{\"someKey\":\"someValue\"}]"
then you should use JSONArray as demonstrated below and not JSONObject
To get a specific string
String aJsonString = jObject.getString("STRINGNAME");
To get a specific boolean
boolean aJsonBoolean = jObject.getBoolean("BOOLEANNAME");
To get a specific integer
int aJsonInteger = jObject.getInt("INTEGERNAME");
To get a specific long
long aJsonLong = jObject.getLong("LONGNAME");
To get a specific double
double aJsonDouble = jObject.getDouble("DOUBLENAME");
To get a specific JSONArray:
JSONArray jArray = jObject.getJSONArray("ARRAYNAME");
To get the items from the array
for (int i=0; i < jArray.length(); i++)
{
try {
JSONObject oneObject = jArray.getJSONObject(i);
// Pulling items from the array
String oneObjectsItem = oneObject.getString("STRINGNAMEinTHEarray");
String oneObjectsItem2 = oneObject.getString("anotherSTRINGNAMEINtheARRAY");
} catch (JSONException e) {
// Oops
}
}
Writing JSON Parser Class
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
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();
} 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;
}
}
Parsing JSON Data
Once you created parser class next thing is to know how to use that class. Below i am explaining how to parse the json (taken in this example) using the parser class.
2.1. Store all these node names in variables: In the contacts json we have items like name, email, address, gender and phone numbers. So first thing is to store all these node names in variables. Open your main activity class and declare store all node names in static variables.
// url to make request
private static String url = "http://api.9android.net/contacts";
// JSON Node names
private static final String TAG_CONTACTS = "contacts";
private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL = "email";
private static final String TAG_ADDRESS = "address";
private static final String TAG_GENDER = "gender";
private static final String TAG_PHONE = "phone";
private static final String TAG_PHONE_MOBILE = "mobile";
private static final String TAG_PHONE_HOME = "home";
private static final String TAG_PHONE_OFFICE = "office";
// contacts JSONArray
JSONArray contacts = null;
2.2. Use parser class to get JSONObject and looping through each json item. Below i am creating an instance of JSONParser class and using for loop i am looping through each json item and finally storing each json data in variable.
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
try {
// Getting Array of Contacts
contacts = json.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for(int i = 0; i < contacts.length(); i++){
JSONObject c = contacts.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
String address = c.getString(TAG_ADDRESS);
String gender = c.getString(TAG_GENDER);
// Phone number is agin JSON Object
JSONObject phone = c.getJSONObject(TAG_PHONE);
String mobile = phone.getString(TAG_PHONE_MOBILE);
String home = phone.getString(TAG_PHONE_HOME);
String office = phone.getString(TAG_PHONE_OFFICE);
}
} catch (JSONException e) {
e.printStackTrace();
}
I've coded up a simple example for you and annotated the source. The example shows how to grab live json and parse into a JSONObject for detail extraction:
try{
// 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);
} catch(Exception e){
// In your production code handle any errors and catch the individual exceptions
e.printStackTrace();
}
Once you have your JSONObject refer to the SDK for details on how to extract the data you require.
Here is a sample of my json_encode in PHP:
print(json_encode($row));
leads to {"AverageRating":"4.3"} which is good.
But in Java, I can not seem to grab this 4.3 value. Here it is (for an Android project) I have edited non-relevant data.
public class Rate extends ListActivity {
JSONArray jArray;
String result = null;
InputStream is = null;
StringBuilder sb = null;
String Item, Ratings, Review, starAvg;
RatingBar ratingsBar;
ArrayList<NameValuePair> param;
public void onCreate(Bundle savedInstanceState) {
starAvg = "0"; // Sets to 0 in case there are no ratings yet.
new starRatingTask().execute();
ratingsBar = (RatingBar) findViewById(R.id.theRatingBar);
class starRatingTask extends AsyncTask<String, String, Void> {
InputStream is = null;
String result = "";
#Override
protected Void doInBackground(String... params) {
String url_select = "http://www.---.com/---/average_stars.php";
ArrayList<NameValuePair> param = new ArrayList<NameValuePair>();
param.add(new BasicNameValuePair("item", Item));
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url_select);
try {
httpPost.setEntity(new UrlEncodedFormEntity(param));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
// read content
is = httpEntity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection " + e.toString());
}
try {
BufferedReader br = new BufferedReader(
new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = "";
while ((line = br.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
} catch (Exception e) {
Log.e("log_tag", "Error converting result " + e.toString());
}
return null;
}
protected void onPostExecute(Void v) {
String starAvgTwo = null;
try {
jArray = new JSONArray(result);
JSONObject json_data = null;
for (int i = 0; i < jArray.length(); i++) {
json_data = jArray.getJSONObject(i);
starAvg = json_data.getString("AverageRating");
starAvgTwo = starAvg;
}
} catch (JSONException e1) {
Toast.makeText(getBaseContext(), "No Star Ratings!",
Toast.LENGTH_LONG).show();
} catch (ParseException e1) {
e1.printStackTrace();
}
Toast.makeText(getBaseContext(), starAvgTwo,
Toast.LENGTH_LONG).show();
ratingsBar.setRating(Float.valueOf(starAvg));
}
}
That second toast produces a blank (I assume a "" - empty string?). If I change the toast variable back to starAvg, then it toasts "0".
How can I retrieve the value of 4.3.
As we discussed in the comments on the original question, the PHP is sending down as single JSONObject rather than an array. Parsing as a JSONObject is required in it's present state; however, if you begin sending down an array of your value objects, then you'd use JSONArray to parse it.
I think your JSON doesn't contain array. so just do this:
JSONObject jsonObject = new JSONObject(result); //to convert string to be a JSON object
String averageRating = jsonObject.getString("AverageRating"); //get the value of AverageRating variable
and try toast the averageRating.
and how to get the array from JSON object?
if you have JSON:
{"employees": [
{ "firstName":"John" , "lastName":"Doe" },
{ "firstName":"Anna" , "lastName":"Smith" },
{ "firstName":"Peter" , "lastName":"Jones" }]
}
then use this code
JSONArray jsonArray = new JSONArray(result);
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
Log.i(Rate.class.getName(), jsonObject.getString("firstName"));
}
that code will produce
John Anna Peter
in your LogCat