MY app crashes. I am using custom list view using card View Card View.
My JSON:
{"College":[{"Name":"NITK","Logo":"http:\/\/192.168.43.164\/Webapp\/Collegelogos\/nitk.jpg"},{"Name":"IITR","Logo":"http:\/\/192.168.43.164\/Webapp\/Collegelogos\/iitr.jpg"},{"Name":"NITT","Logo":"http:\/\/192.168.43.164\/Webapp\/Collegelogos\/nitt.jpg"},{"Name":"IITB","Logo":"http:\/\/192.168.43.164\/Webapp\/Collegelogos\/iitb.png"},{"Name":"IITG","Logo":"http:\/\/192.168.43.164\/Webapp\/Collegelogos\/iitg.png"},{"Name":"IITD","Logo":"http:\/\/192.168.43.164\/Webapp\/Collegelogos\/iitd.png"},{"Name":"BITS","Logo":"http:\/\/192.168.43.164\/Webapp\/Collegelogos\/bits.png"}]}
My code:
public class MainActivity extends AppCompatActivity {
private List<College> listcollege;
//Creating Views
private RecyclerView recyclerView;
private RecyclerView.LayoutManager layoutManager;
private RecyclerView.Adapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Initializing Views
recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
recyclerView.setHasFixedSize(true);
layoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
listcollege = new ArrayList<>();
adapter = new CardAdapter(this, listcollege);
recyclerView.setAdapter(adapter);
getData();
}
private void getData(){
//Showing a progress dialog
final ProgressDialog loading = ProgressDialog.show(this,"Loading Data", "Please wait...",false,false);
//Creating a json array request
JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET,Config.DATA_URL,null,
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
//Dismissing progress dialog
Toast.makeText(MainActivity.this, "sachin", Toast.LENGTH_SHORT).show();
loading.dismiss();
try {
// College
JSONArray jsonArrayCollege = response.getJSONArray("College");
// calling method to parse json array
parseData(jsonArrayCollege);
}
catch (JSONException e)
{
e.printStackTrace();
}
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
});
RequestQueue requestQueue = Volley.newRequestQueue(this);
requestQueue.add(jsonObjectRequest);
}
public void parseData(JSONArray array) {
for (int i = 0; i < array.length(); i++) {
College college = new College();
JSONObject json = null;
try {
json = array.getJSONObject(i);
college.setImageUrl(json.getString(Config.TAG_IMAGE_URL));
String s = (json.getString(Config.TAG_NAME));
Toast.makeText(this, s, Toast.LENGTH_SHORT).show();
college.setName(s);
} catch (JSONException e) {
e.printStackTrace();
}
listcollege.add(college);
}
adapter.notifyDataSetChanged();
}
}
RequestQueue requestQueue = Volley.newRequestQueue(this);
requestQueue.add(jsonObjectRequest);
}
public void parseData(JSONArray array) {
for (int i = 0; i < array.length(); i++) {
College college = new College();
JSONObject json = null;
try {
json = array.getJSONObject(i);
college.setImageUrl(json.getString(Config.TAG_IMAGE_URL));
String s = (json.getString(Config.TAG_NAME));
Toast.makeText(this, s, Toast.LENGTH_SHORT).show();
college.setName(s);
} catch (JSONException e) {
e.printStackTrace();
}
listcollege.add(college);
}
adapter.notifyDataSetChanged();
}
}
Errors, Android Monitor:
FATAL EXCEPTION: main Process: com.example.sachin.volleyrecycle, PID: 6825 java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.String.hashCode()' on a null object reference at com.android.volley.Request.(Request.java:136) at com.android.volley.toolbox.ImageRequest.(ImageRequest.java:71) at com.android.volley.toolbox.ImageLoader.get(ImageLoader.java:219) at com.android.volley.toolbox.ImageLoader.get(ImageLoader.java:171) at com.example.sachin.volleyrecycle.CardAdapter.onBindViewHolder(CardAdapter.java:48) at com.example.sachin.volleyrecycle.CardAdapter.onBindViewHolder(CardAdapter.java:24) at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6356) at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6389) at android.support.v7.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5335) at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5598) at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5440) at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5436) at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2224) at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1551) at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1511) at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:595) at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3583) at android.support.v7.widget.RecyclerView.onMeasure(RecyclerView.java:3025) at android.view.View.measure(View.java:19857) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083) at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1464) at android.widget.LinearLayout.measureVertical(LinearLayout.java:758) at android.widget.LinearLayout.onMeasure(LinearLayout.java:640) at android.view.View.measure(View.java:19857) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083) at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:139) at android.view.View.measure(View.java:19857) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083) at android.support.v7.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:393) at android.view.View.measure(View.java:19857) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083) at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) at android.view.View.measure(View.java:19857) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083) at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1464) at android.widget.LinearLayout.measureVertical(LinearLayout.java:758) at android.widget.LinearLayout.onMeasure(LinearLayout.java:640) at android.view.View.measure(View.java:19857) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083)
