I'm trying to get a json response from api call.But some errors has occurred. Please tell me what is wrong with my code...My code is like this.
private JSONObject responseJson;
private void apiRequest() {
mQueue = Volley.newRequestQueue(MainActivity.this);
String mRequestUrl = "http://hogehoge";
JsonObjectRequest jsonOR = new JsonObjectRequest(Request.Method.GET, mRequestUrl, null, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
try {
if (response.getJSONObject("response").has("error")) {
throw new NoSuchElementException(msg);
}else{
responseJson = response;
}
} catch (JSONException e) {
e.printStackTrace();
}
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
// error
}
});
jsonOR.setRetryPolicy(new DefaultRetryPolicy(5000, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
mQueue.add(jsonOR);
}
and error messages are this.
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.user.mymaterialapp/com.example.user.mymaterialapp.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String org.json.JSONObject.toString()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String org.json.JSONObject.toString()' on a null object reference
at com.example.user.mymaterialapp.MainActivity.onCreate(MainActivity.java:75)
at android.app.Activity.performCreate(Activity.java:5933)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)