Reputation: 1092
I am developing an application where I want to hit the web services and get the data. I am using Google Volley
to hit the web service. I am doing it all right but unable to parse JSON
using GSON
. I am unable to understand where I am doing it wrong.
Here is the URL of Web Services
Here is what I am doing
RequestQueue requestQueue = Volley.newRequestQueue(this);
JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(
Request.Method.GET,
"https://api.github.com/repos/crashlytics/secureudid/issues",
null,
new MyListner(),
new MyErrorListner()
);
requestQueue.add(jsonObjectRequest);
}
class MyListner implements Response.Listener<JSONObject>
{
@Override
public void onResponse(JSONObject response) {
Gson gson = new Gson();
Results results = gson.fromJson(response.toString(), Results.class);
for(Test t : results.getmResults())
{
Log.e("Tag", t.toString());
}
}
}
class MyErrorListner implements Response.ErrorListener
{
@Override
public void onErrorResponse(VolleyError error) {
Log.e("Error", error.getMessage());
}
}
The other classes are given below
public class Results {
private ArrayList<Test> mResults;
public void setResults(ArrayList<Test> results)
{
mResults = results;
}
public ArrayList<Test> getmResults()
{
return mResults;
}
}
public class Test {
@SerializedName("title")
private String mTitle;
@SerializedName("user")
private User mUser;
@SerializedName("created_at")
private String mCreatedAt;
@SerializedName("body")
private String mBody;
@SerializedName("updated_at")
private String mUpdatedAt;
public String getmBody() {
return mBody;
}
public void setmBody(String mBody) {
this.mBody = mBody;
}
public String getmUpdatedAt() {
return mUpdatedAt;
}
public void setmUpdatedAt(String mUpdatedAt) {
this.mUpdatedAt = mUpdatedAt;
}
public String getmCreatedAt() {
return mCreatedAt;
}
public void setmCreatedAt(String mCreatedAt) {
this.mCreatedAt = mCreatedAt;
}
public User getmUser() {
return mUser;
}
public void setmUser(User mUser) {
this.mUser = mUser;
}
public String getmTitle() {
return mTitle;
}
public void setmTitle(String mTitle) {
this.mTitle = mTitle;
}
@Override
public String toString() {
return mTitle + " " + mBody + " " + mCreatedAt + " " + mUpdatedAt + " " + mUser.getmLogin() + " ";
}
}
public class User {
@SerializedName("login")
private String mLogin;
public String getmLogin() {
return mLogin;
}
public void setmLogin(String mLogin) {
this.mLogin = mLogin;
}
}
Here is the error what I am getting
org.json.JSONException: Value [{"url":"https:\/\/api.github.com\/repos\/crashlytics\/secureudid\/issues\/28","repository_url":"https:\/\/api.github.com\/repos\/crashlytics\/secureudid","labels_url":"https:\/\/api.github.com\/repos\/crashlytics\/secureudid\/issues\/28\/labels{\/name}","comments_url":"https:\/\/api.github.com\/repos\/crashlytics\/secureudid\/issues\/28\/comments","events_url":"https:\/\/api.github.com\/repos\/crashlytics\/secureudid\/issues\/28\/events","html_url":"https:\/\/github.com\/crashlytics\/secureudid\/pull\/28","id":222258999,"number":28,"title":"Fix broken headings in Markdown files","user":{"login":"bryant1410","id":3905501,"avatar_url":"https:\/\/avatars3.githubusercontent.com\/u\/3905501?v=4","gravatar_id":"","url":"https:\/\/api.github.com\/users\/bryant1410","html_url":"https:\/\/github.com\/bryant1410","followers_url":"https:\/\/api.github.com\/users\/bryant1410\/followers","following_url":"https:\/\/api.github.com\/users\/bryant1410\/following{\/other_user}","gists_url":"https:\/\/api.github.com\/users\/bryant1410\/gists{\/gist_id}","starred_url":"https:\/\/api.github.com\/users\/bryant1410\/starred{\/owner}{\/repo}","subscriptions_url":"https:\/\/api.github.com\/users\/bryant1410\/subscriptions","organizations_url":"https:\/\/api.github.com\/users\/bryant1410\/orgs","repos_url":"https:\/\/api.github.com\/users\/bryant1410\/repos","events_url":"https:\/\/api.github.com\/users\/bryant1410\/events{\/privacy}","received_events_url":"https:\/\/api.github.com\/users\/bryant1410\/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":0,"created_at":"2017-04-17T23:26:47Z","updated_at":"2017-04-17T23:26:47Z","closed_at":null,"author_association":"NONE","pull_request":{"url":"https:\/\/api.github.com\/repos\/crashlytics\/secureudid\/pulls\/28","html_url":"https:\/\/github.com\/crashlytics\/secureudid\/pull\/28","diff_url":"https:\/\/github.com\/crashlytics\/secureudid\/pull\/28.diff","patch_url":"https:\/\/github.com\/crashlytics\/secureudid\/pull\/28.patch"},"body":"GitHub changed the way Markdown headings are parsed, so this change fixes it.\n\nSee [bryant1410\/readmesfix](https:\/\/github.com\/bryant1410\/readmesfix) for more information.\n\nTackles bryant1410\/readmesfix#1\n"},{"url":"https:\/\/api.github.com\/repos\/crashlytics\/secureudid\/issues\/13","repository_url":"https:\/\/api.github.com\/repos\/crashlytics\/secureudid","labels_url":"https:\/\/api.github.com\/repos\/crashlytics\/secureudid\/issues\/13\/labels{\/name}","comments_url":"https:\/\/api.github.com\/repos\/crashlytics\/secureudid\/issues\/13\/comments","events_url":"https:\/\/api.github.com\/repos\/crashlytics\/secureudid\/issues\/13\/events","html_url":"https:\/\/github.com\/crashlytics\/secureudid\/issues\/13","id":3923240,"number":13,"title":"Not working with ARC","user":{"login":"SaschaMoellering","id":1321549,"avatar_url":"https:\/\/avatars0.githubusercontent.com\/u\/1321549?v=4","gravatar_id":"","url":"https:\/\/api.github.com\/users\/SaschaMoellering","html_url":"https:\/\/github.com\/SaschaMoellering","followers_url":"https:\/\/api.github.com\/users\/SaschaMoellering\/followers","following_url":"https:\/\/api.github.com\/users\/SaschaMoellering\/following{\/other_user}","gists_url":"https:\/\/api.github.com\/users\/SaschaMoellering\/gists{\/gist_id}","starred_url":"https:\/\/api.github.com\/users\/SaschaMoellering\/starred{\/owner}{\/repo}","subscriptions_url":"https:\/\/api.github.com\/users\/SaschaMoellering\/subscriptions","organizations_url":"https:\/\/api.github.com\/users\/SaschaMoellering\/orgs","repos_url":"https:\/\/api.github.com\/users\/SaschaMoellering\/repos","events_url":"https:\/\/api.github.com\/users\/SaschaMoellering\/events{\/privacy}","received_events_url":"https:\/\/api.github.com\/users\/SaschaMoellering\/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":10,"created_at":"20
Upvotes: 1
Views: 6418
Reputation: 12347
You are trying to parse an array of object (from your webservices) to an object containing a property mResults
which is an array of object (Test
);
Instead of using Results
class during parsing you need to directly use an ArrayList
of Test
:
Results results = gson.fromJson(response.toString(), Results.class);
should be
ArrayList<Test> results = gson.fromJson(response.toString(), new TypeToken<ArrayList<Test>>(){}.getType());
As ArrayList is a generic it's not possible to use ArrayList<Test>.class
to get a representation of the data type, we must use TypeToken. What is TypeToken?
TypeToken represents a generic type T. Java doesn't yet provide a way to represent generic types, so this class does. Forces clients to create a subclass of this class which enables retrieval the type information even at runtime.
getType
returns the type of the class used to build TypeToken and so we can use it in gson fromJson()
parsing method.
--
Second problem:
Your are using JsonObjectRequest
but server response is a Json array so you need to use JsonArrayRequest
and so update MyListner
to use JSONArray
instead of JSONObject
.
BUT
As your are parsing server response manually you can use StringRequest
and so avoid parsing step of Volley
.
StringRequest jsonObjectRequest = new StringRequest(
Request.Method.GET,
"https://api.github.com/repos/crashlytics/secureudid/issues",
new MyListner(),
new MyErrorListner()
);
and MyListner
is now directly using String
:
class MyListner implements Response.Listener<String> {
@Override
public void onResponse(String response) {
Gson gson = new Gson();
ArrayList<Test> results = gson.fromJson(response, new TypeToken<ArrayList<Test>>() {}.getType());
for (Test t : results) {
Log.e("Tag", t.toString());
}
}
}
Upvotes: 1