Getting string from Json - java

I am new in json.My question is very simple.I have some array in my json file and also a string type of data.
Now I want to get the single text, name: anounce in my java class from json file.
How can i get this string from json ?
or any other way to get this ?
Json file
[{
"title": "KalerKantha | OfftechIT",
"image": "",
"link": "http://www.kalerkantho.com/"
}, {
"title": "Prothom Alo | OfftechIT",
"image": "",
"link": "http://www.prothom-alo.com/"
},
...
{
"anounce": "I need this this text"
}
]
Java Code
JsonArrayRequest movieReq = new JsonArrayRequest(url, new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
Log.d(TAG, response.toString());
hidePDialog();
// Parsing json
for (int i = 0; i < response.length(); i++) {
try {
JSONObject obj = response.getJSONObject(i);
Movie movie = new Movie();
movie.setTitle(obj.getString("title"));
movie.setThumbnailUrl(obj.getString("image"));
movie.setLink(obj.getString("link").toString());
// adding movie to movies array
movieList.add(movie);
} catch (JSONException e) {
e.printStackTrace();
}
}
// notifying list adapter about data changes
// so that it renders the Grid view with updated data
adapter.notifyDataSetChanged();
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
if (error instanceof NoConnectionError){
hidePDialog();
Toast.makeText(getActivity(), " No Internet connection! \n Please check you connection", Toast.LENGTH_LONG).show();
}};
});

You simply make check the announce is present in the JSON or not
for (int i = 0; i < response.length(); i++) {
try {
JSONObject obj = response.getJSONObject(i);
if(obj.has("anounce"))
{
String anounce= obj.getString("anounce");
}
else
{
Movie movie = new Movie();
movie.setTitle(obj.getString("title"));
movie.setThumbnailUrl(obj.getString("image"));
movie.setLink(obj.getString("link").toString());
// adding movie to movies array
movieList.add(movie);
}
} catch (JSONException e) {
e.printStackTrace();
}

Use optString method. It would return the value if node exists and String.empty is node is not found.
From Documentation
public String optString (String name)
Returns the value mapped by name if it exists, coercing it if necessary, or the empty string if no such mapping exists.
Do this
try {
JSONObject obj = response.getJSONObject(i);
String announce = obj.optString("anounce");
Movie movie = new Movie();
movie.setTitle(obj.optString("title"));
movie.setThumbnailUrl(obj.optString("image"));
movie.setLink(obj.optString("link"));
// adding movie to movies array
movieList.add(movie);
} catch (JSONException e) {
e.printStackTrace();
}
Update: Using optString is much better, but if you don't want to use it then do this
try {
JSONObject obj = response.getJSONObject(i);
if(i == response.length() -1)
{
String announce = obj.getString("anounce");
}
else
{
Movie movie = new Movie();
movie.setTitle(obj.getString("title"));
movie.setThumbnailUrl(obj.getString("image"));
movie.setLink(obj.getString("link").toString());
// adding movie to movies array
movieList.add(movie);
}
} catch (JSONException e) {
e.printStackTrace();
}

The Structure of your JSON is hard. But if you really want to get the string. Try this. Add this inside in for loop.
String data = (obj.getString("announce") != null) ? obj.getString("announce") : "";
// If you Movie has this annouce in your settler Getter if not try to add it.
Movie.setAnnounce(data);

Your code look like good but Are you add the request to queue
like:-
AppController.getInstance().addToRequestQueue(movieReq);
movieReq is JsonArrayRequest,
Please check it. and
String manounce=obj.getString("anounce");

Related

Split jsonarray data into multiple list using array value

I want to split an ArrayList according to the existing data, Like as
category etc.
I try nested for loop and add them into list.but It's not working.
String url = "http://27.147.169.230/UpSkillService/UpSkillsService.svc/" + "GetCNCCourseDefByorg/" + 1 +"/" +1;
Ion.with(getApplicationContext())
.load("GET",url)
.setBodyParameter("","")
.asString()
.setCallback(new FutureCallback<String>() {
#Override
public void onCompleted(Exception e, String result) {
Log.d("Result",result);
try {
JSONObject obj =new JSONObject(result);
JSONArray jsonArray = obj.getJSONArray("GetCNCCourseDefByorgResult");
//Arrays.sort(new JSONArray[]{jsonArray});
if(obj.isNull("GetCNCCourseDefByorgResult"))
{
Toast.makeText(getApplicationContext(),"No Course Found",Toast.LENGTH_SHORT).show();
}
else if (!obj.equals(null)) {
String cata="";
Log.d("Resul3", jsonArray.toString());
for (int i = 0; i < jsonArray.length(); i++) {
final CourseCatagory catagoryModel = new CourseCatagory();
JSONObject course = jsonArray.getJSONObject(i);
CourseList courselist = new CourseList();
if(cata!=course.getString("CategoryName"))
{
Log.d("Catagory",cata);
catagoryModel.setCategoryName(course.getString("CategoryName"));
arrayListcatagory.add(catagoryModel);
for (int j=0;j<jsonArray.length();j++)
{
JSONObject cat1 = jsonArray.getJSONObject(j);
cata=cat1.getString("CategoryName");
Log.d("cat",cata);
if(cat1.getString("CategoryName")==course.getString("CategoryName"))
{
courselist.setCourseName(cat1.getString("CourseName"));
courselist.setCourseCode(cat1.getString("CourseCode"));
courselist.setWishFlag(cat1.getInt("WishFlag"));
Log.d("Course",cat1.getString("CourseName"));
arrayListcourse.add(courselist);
}
else {
}
}
}
catagoryModel.setCourseList(arrayListcourse);
}
adapter.notifyDataSetChanged();
}
} catch (JSONException e1) {
e1.printStackTrace();
}
}
});
}
`
I want as catagory, under catagory course shown which match catagory name.
Accounting>Introduction Accounting,Advance accounting
Finance>Introduction Finance
You can Use HashMap<String,ArrayList<CategoryDetails>> to resolve your Problem.
First Create CategoryDetails POJO class
class CategoryDetails {
private courseName;
private courseCode;
private wishFlag;
//make setter and getter methods for above fields.
}
Then use category Name as key in HashMap to differentiate as mentioned in first line of my answer.
Map<String,ArrayList<CategoryDetails>> listCategory = new HashMap<String,ArrayList<CategoryDetails>>;

I have difficulty printing java json data

I currently received the json file in java, turned the json file on the formun, debugged it, and tried sysout.
The problem is, I try to output to the table in jsp, but only the last source from json comes out.
How can we solve this?
#RequestMapping(value = "spaghettiSub", method = RequestMethod.POST)
public String spaghetti(ModelMap modelMap) {
JSONParser jsonParser = new JSONParser();
try{
JSONArray page = (JSONArray) jsonParser.parse(new FileReader("d:\\spaghetti.json"));
int pageCnt = page.size();
Map<String,String> map = new HashMap<String,String>();
List<Map<String,String>> spaghettiList = new ArrayList<Map<String,String>>();
for(int i = 0; i < pageCnt; i++) {
Object obj = page.get(i);
JSONObject jsonObject = (JSONObject) obj;
String no = (String) jsonObject.get("no");
String name = (String) jsonObject.get("name");
String explanation= (String) jsonObject.get("explanation");
map.put("no", no);
map.put("name", name);
map.put("explanation", explanation);
spaghettiList.add(map);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
}
return "sub/" + this.urlbase + "/spaghetti";
}
json
[
{
"no": "1",
"name": "Spaghettoni",
"explanation": "It is commonly used in the Carbonara Spaghetti, which is about 2mm thick."
},
{
"no": "2",
"name": "Spaghettini",
"explanation": "Spaghetti 1.6mm thick"
},
{
"no": "3",
"name": "Fedelini",
"explanation": "Spaghetti from 1.3mm to 1.5mm thick"
}]
you have to move this Map<String,String> map = new HashMap<String,String>(); inside your for loop.
Note:
As JB Nizet mentioned start using objects instead of JsonArray.
First thing first
Solve Issue
You are only getting last row in your JSP is because you have declared your Map outside of for loop.
If you are in hurry and have no time in world just move this
Map<String,String> map = new HashMap<String,String>();
inside
for(int i = 0; i < pageCnt; i++) {
This will solve your problem.
Improve your Code
But you can make it way more better and efficient by doing something like this
Define a DTO class
public class MyData {
private String no;
private String name;
private String explanation;
// getter setter
}
Use this DTO class to fill values like you did for Map
The whole code looks something like this.
#RequestMapping(value = "spaghettiSub", method = RequestMethod.POST)
public String spaghetti(ModelMap modelMap) {
JSONParser jsonParser = new JSONParser();
try{
JSONArray page = (JSONArray) jsonParser.parse(new FileReader("d:\\spaghetti.json"));
int pageCnt = page.size();
List<MyData> spaghettiList = new ArrayList<MyData>();
for(int i = 0; i < pageCnt; i++) {
MyData mydata = new MyData();
Object obj = page.get(i);
JSONObject jsonObject = (JSONObject) obj;
String no = (String) jsonObject.get("no");
String name = (String) jsonObject.get("name");
String explanation= (String) jsonObject.get("explanation");
mydata.setNo(no);
mydata.setName(name);
mydata.setExplanation(explanation);
spaghettiList.add(mydata);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
}
return "sub/" + this.urlbase + "/spaghetti";
}

Parse multiple items in JSON into an array

I have a client that retrieves some json from this page. The json content looks like this:
{
"0": {
"name": "McDonalds 2",
"address": "892 West 75th Street, Naperville, IL 60540"
},
"1": {
"name": "McDonalds 1",
"address": "1298 South Naper Boulevard, Naperville, IL 60540"
},
"2": {
"name": "Burger King 1",
"address": "2040 Aurora Avenue, Naperville, IL, 60540"
}
}
I'm having problems parsing it. I always get an exception when trying to parse anything. It's my first time doing json so I might be doing something really bad. This is my code:
public static void parse(String jsonData)
{
JSONObject jsonObject = new JSONObject();
try
{
jsonObject = new JSONObject(jsonData);
}
catch (JSONException e)
{
e.printStackTrace();
}
try
{
// exception happens here when trying to access data
JSONObject name = ((JSONArray)jsonObject.get("0")).getJSONObject(0)
.getJSONObject("name");
JSONObject address = ((JSONArray)jsonObject.get("0")).getJSONObject(0)
.getJSONObject("address");
} catch (JSONException e) {}
}
How an I retrieve the name and address of each json item to convert it into a restaurant object?
The format of the JSON is wrong. Please refer to this link and the right code is below. You will know what to do.
public static void parse(String jsonData) {
ArrayList<Restaurant> restaurantList= new ArrayList<Restaurant>();
JSONObject jsonObject;
JSONObject jsonRestaurant;
try {
jsonObject= new JSONObject(jsonData);
for(int i=0;i<3;i++) {
Restaurant restaurant= new Restaurant();
jsonRestaurant= jsonObject.getJSONObject(Integer.toString(i));
restaurant.name= jsonRestaurant.getString("name");
restaurant.address= jsonRestaurant.getString("address");
restaurantList.add(restaurant);
}
}
catch(JSONException e) {
e.printStackTrace();
}
}

How to modify values of JsonObject / JsonArray directly?

Once i have parsed a JSON String into a GSON provided JsonObject class, (assume that i do not wish to parse it into any meaningful data objects, but strictly want to use JsonObject), how am i able to modify a field / value of a key directly?
I don't see an API that may help me.
https://static.javadoc.io/com.google.code.gson/gson/2.6.2/com/google/gson/JsonObject.html
Strangely, the answer is to keep adding back the property. I was half expecting a setter method. :S
System.out.println("Before: " + obj.get("DebugLogId")); // original "02352"
obj.addProperty("DebugLogId", "YYY");
System.out.println("After: " + obj.get("DebugLogId")); // now "YYY"
This works for modifying childkey value using JSONObject.
import used is
import org.json.JSONObject;
ex json:(convert json file to string while giving as input)
{
"parentkey1": "name",
"parentkey2": {
"childkey": "test"
},
}
Code
JSONObject jObject = new JSONObject(String jsoninputfileasstring);
jObject.getJSONObject("parentkey2").put("childkey","data1");
System.out.println(jObject);
output:
{
"parentkey1": "name",
"parentkey2": {
"childkey": "data1"
},
}
Since 2.3 version of Gson library the JsonArray class have a 'set' method.
Here's an simple example:
JsonArray array = new JsonArray();
array.add(new JsonPrimitive("Red"));
array.add(new JsonPrimitive("Green"));
array.add(new JsonPrimitive("Blue"));
array.remove(2);
array.set(0, new JsonPrimitive("Yelow"));
Another approach would be to deserialize into a java.util.Map, and then just modify the Java Map as wanted. This separates the Java-side data handling from the data transport mechanism (JSON), which is how I prefer to organize my code: using JSON for data transport, not as a replacement data structure.
It's actually all in the documentation.
JSONObject and JSONArray can both be used to replace the standard data structure.
To implement a setter simply call a remove(String name) before a put(String name, Object value).
Here's an simple example:
public class BasicDB {
private JSONObject jData = new JSONObject;
public BasicDB(String username, String tagline) {
try {
jData.put("username", username);
jData.put("tagline" , tagline);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public String getUsername () {
String ret = null;
try {
ret = jData.getString("username");
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return ret;
}
public void setUsername (String username) {
try {
jData.remove("username");
jData.put("username" , username);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public String getTagline () {
String ret = null;
try {
ret = jData.getString("tagline");
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return ret;
}
public static JSONObject convertFileToJSON(String fileName, String username, List<String> list)
throws FileNotFoundException, IOException, org.json.simple.parser.ParseException {
JSONObject json = new JSONObject();
String jsonStr = new String(Files.readAllBytes(Paths.get(fileName)));
json = new JSONObject(jsonStr);
System.out.println(json);
JSONArray jsonArray = json.getJSONArray("users");
JSONArray finalJsonArray = new JSONArray();
/**
* Get User form setNewUser method
*/
//finalJsonArray.put(setNewUserPreference());
boolean has = true;
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
finalJsonArray.put(jsonObject);
String username2 = jsonObject.getString("userName");
if (username2.equals(username)) {
has = true;
}
System.out.println("user name are :" + username2);
JSONObject jsonObject2 = jsonObject.getJSONObject("languages");
String eng = jsonObject2.getString("Eng");
String fin = jsonObject2.getString("Fin");
String ger = jsonObject2.getString("Ger");
jsonObject2.put("Eng", "ChangeEnglishValueCheckForLongValue");
System.out.println(" Eng : " + eng + " Fin " + fin + " ger : " + ger);
}
System.out.println("Final JSON Array \n" + json);
jsonArray.put(setNewUserPreference());
return json;
}

How to loop through json data in android

As mentioned in the title. How can I loop through my json data that I am getting from server. My getting this kind of json data
{
"tag":"home",
"success":1,
"error":0,
"uid":"4fc8f94f1a51c5.32653037",
"name":"Saleem",
"profile_photo":"http:\/\/example.info\/android\/profile_photos\/profile1.jpg",
"places":
{
"place_photo":"http:\/\/example.info\/android\/places_photos\/place1.jpg",
"created_at":"2012-06-02 00:00:00",
"seeked":"0"
}
}
{
"tag":"home",
"success":1,
"error":0,
"uid":"4fc8f94f1a51c5.32653037",
"name":"Name",
"profile_photo":"http:\/\/example.info\/android\/profile_photos\/profile1.jpg",
"places":
{
"place_photo":"http:\/\/example.info\/android\/places_photos\/place1.jpg",
"created_at":"2012-06-02 00:00:00",
"seeked":"0"
}
}
{
"tag":"home",
"success":1,
"error":0,
"uid":"4fc8f94f1a51c5.32653037",
"name":"Name",
"profile_photo":"http:\/\/example.info\/android\/profile_photos\/profile1.jpg",
"places":
{
"place_photo":"http:\/\/example.info\/android\/places_photos\/place1.jpg",
"created_at":"2012-06-02 00:00:00",
"seeked":"0"
}
}
here is where I am getting my json data
public class Home extends Activity {
Button btnLogout;
ScrollView svHome;
UserFunctions userFunctions;
LoginActivity userid;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
userid = new LoginActivity();
svHome = (ScrollView)findViewById(R.id.svHome);
setContentView(R.layout.home);
userFunctions = new UserFunctions();
/***********************************************************/
//here is where my above mentioned json data is
JSONObject json = userFunctions.homeData();
try {
if(json != null && json.getString("success") != null) {
//login_error.setText("");
String res = json.getString("success");
//userid = json.getString("uid").toString();
if(Integer.parseInt(res) == 1) {
//currently this only shows the first json object
Log.e("pla", json.toString());
} else {
//login_error.setText(json.getString("error_msg"));
}
} else {
Toast.makeText(getBaseContext(), "No data", Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
/*******************************************************/
}
}
Update
After make changes accroding to the link given in the answer. Here are my changes
/***********************************************************/
JSONObject json = userFunctions.homeData();
String jsonData = json.toString();
try {
if(json != null && json.getString("success") != null) {
//login_error.setText("");
String res = json.getString("success");
//userid = json.getString("uid").toString();
if(Integer.parseInt(res) == 1) {
JSONArray jsonArray = new JSONArray(jsonData);
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
Log.e("Object", jsonObject.getString("places"));
//Log.i(ParseJSON.class.getName(), jsonObject.getString("text"));
}
Log.e("pla", json.toString());
} else {
//login_error.setText(json.getString("error_msg"));
}
} else {
Toast.makeText(getBaseContext(), "No data", Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
Please look over the link
http://www.androidhive.info/2012/01/android-json-parsing-tutorial/
an if possible made the changes in json, as there is no array braces "[" "]" in json and you need that to itrate in loop
json should be like that
{
"arrayKey": [
{
"tag": "home",
"success": 1,
"error": 0,
"uid": "4fc8f94f1a51c5.32653037",
"name": "Saleem",
"profile_photo": "http://example.info/android/profile_photos/profile1.jpg",
"places": {
"place_photo": "http://example.info/android/places_photos/place1.jpg",
"created_at": "2012-06-02 00:00:00",
"seeked": "0"
}
},
{
"tag": "home",
"success": 1,
"error": 0,
"uid": "4fc8f94f1a51c5.32653037",
"name": "Saleem",
"profile_photo": "http://example.info/android/profile_photos/profile1.jpg",
"places": {
"place_photo": "http://example.info/android/places_photos/place1.jpg",
"created_at": "2012-06-02 00:00:00",
"seeked": "0"
}
}
]
}
You could use the json libraries like the following:
import org.json.JSONArray;
import org.json.JSONObject;
which allows you to read json data into array like this:
JSONArray jsonArray = new JSONArray([your json data]);
Try this tutorial: http://www.vogella.com/articles/AndroidJSON/article.html
one other way I'll recommend is Use GSON library, It is easy end pain less. for well formatted Json
As your logcat states, you're trying to convert a JSONObject to a JSONArray:
org.json.JSONException: Value {"uid":"4fc8f94f1a51c5.32653037","places":{"place_photo":"http://example.info/android/places_photos/place1.jpg","created_at":"2012-06-02 00:00:00","seeked":"0","longitude":"24.943514","latitude":"60.167112"},"error":0,"success":1,"tag":"home","profile_photo":"http://example.info/android/profile_photos/profile1.jpg","name":"Zafar Saleem"} of type org.json.JSONObject cannot be converted to JSONArray
Try to debug the code - find out where the exception is thrown, and make a JSONObject there instead of a JSONArray.

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