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Android Studio – No adapter attached; skipping layout while using volley

i am using volley here to get data from xampp server through my api(works fine on postman)
but getting this on running the code,Toast defined onErrorResponse is shown on display as soon as the app opens and app does not crash.
read many solutions to this ,many were related to fragments..i didn’t use fragments…
also in my code i think when i have called the setAdapter method on recyclerview ,i have just above it defined myAdapter

MyAdapter myAdapter = new MyAdapter(data);
recyclerView.setAdapter(myAdapter);

main activity.java

package com.example.poetryapp;

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;

import com.android.volley.AuthFailureError;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import com.example.poetryapp.adapter.MyAdapter;
import com.example.poetryapp.model.PoetryModel;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

import java.util.HashMap;
import java.util.Map;

public class MainActivity extends AppCompatActivity {
    RecyclerView recyclerView;


    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        recyclerView = findViewById(R.id.poetry_recyclerView);
        recyclerView.setLayoutManager(new LinearLayoutManager(MainActivity.this));


        loaddata();
    }

    private void loaddata() {

        String url = "http://192.168.137.198/poetryapi/getPoetryRead.php.php";

        StringRequest stringRequest = new StringRequest(Request.Method.POST, url, new com.android.volley.Response.Listener<String>() {
            @Override
            public void onResponse(String response) {

                GsonBuilder gsonBuilder = new GsonBuilder();
                Gson gson = gsonBuilder.create();

                PoetryModel data[]=gson.fromJson(response,PoetryModel[].class);

                MyAdapter myAdapter = new MyAdapter(data);
                recyclerView.setAdapter(myAdapter);
                myAdapter.notifyDataSetChanged();

                Log.e("success",response);
            }
        }, new com.android.volley.Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Toast.makeText(getApplicationContext(),error.toString(),Toast.LENGTH_LONG).show();
            }
        }){
            @Override
            protected Map<String, String> getParams() throws AuthFailureError {
                Map<String,String> params=new HashMap<>();
                return params;
            }
        };
        RequestQueue requestQueue = Volley.newRequestQueue(this);
        requestQueue.add(stringRequest);



    }
    }

MyAdapter.java

package com.example.poetryapp.adapter;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import com.example.poetryapp.R;
import com.example.poetryapp.model.PoetryModel;

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.viewHolder> {

    PoetryModel data[];

    public MyAdapter(PoetryModel[] data) {
        this.data = data;
    }

    @NonNull
    @Override
    public viewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.poetry_list_view,parent,false);
        return new viewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull viewHolder holder, int position) {
        holder.t1_name.setText(data[position].getPoet_name());
        holder.t2_data.setText(data[position].getPoetry_data());
        holder.t3_date_time.setText(data[position].getDate_time());
    }

    @Override
    public int getItemCount() {
        return data.length;
    }

    class viewHolder extends RecyclerView.ViewHolder{
        TextView t1_name,t2_data,t3_date_time;
        public viewHolder(@NonNull View itemView) {
            super(itemView);

            t1_name=itemView.findViewById(R.id.tv_poetName);
            t2_data=itemView.findViewById(R.id.tv_poetryData);
            t3_date_time=itemView.findViewById(R.id.tv_poet_dateTime);

        }
    }


}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/main_toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="@color/black" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@id/main_toolbar"
        android:orientation="vertical"
        >

        <androidx.recyclerview.widget.RecyclerView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/poetry_recyclerView"
            />

    </LinearLayout>

</RelativeLayout>

logcat error message

2021-09-09 09:38:45.963 29496-29496/com.example.poetryapp E/RecyclerView: No adapter attached; skipping layout
2021-09-09 09:38:46.004 29496-29496/com.example.poetryapp E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.poetryapp, PID: 29496
    com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2 path $
        at com.google.gson.Gson.fromJson(Gson.java:944)
        at com.google.gson.Gson.fromJson(Gson.java:897)
        at com.google.gson.Gson.fromJson(Gson.java:846)
        at com.google.gson.Gson.fromJson(Gson.java:817)
        at com.example.poetryapp.MainActivity$1.onResponse(MainActivity.java:53)
        at com.example.poetryapp.MainActivity$1.onResponse(MainActivity.java:46)
        at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:82)
        at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:29)
        at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:102)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:223)
        at android.app.ActivityThread.main(ActivityThread.java:7868)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:981)
     Caused by: java.lang.IllegalStateException: Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2 path $
        at com.google.gson.stream.JsonReader.beginArray(JsonReader.java:349)
        at com.google.gson.internal.bind.ArrayTypeAdapter.read(ArrayTypeAdapter.java:70)
        at com.google.gson.Gson.fromJson(Gson.java:932)
        at com.google.gson.Gson.fromJson(Gson.java:897) 
        at com.google.gson.Gson.fromJson(Gson.java:846) 
        at com.google.gson.Gson.fromJson(Gson.java:817) 
        at com.example.poetryapp.MainActivity$1.onResponse(MainActivity.java:53) 
        at com.example.poetryapp.MainActivity$1.onResponse(MainActivity.java:46) 
        at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:82) 
        at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:29) 
        at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:102) 
        at android.os.Handler.handleCallback(Handler.java:938) 
        at android.os.Handler.dispatchMessage(Handler.java:99) 
        at android.os.Looper.loop(Looper.java:223) 
        at android.app.ActivityThread.main(ActivityThread.java:7868) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:981) 

my url returns this

{
    "status": "1",
    "message": "record is not empty",
    "data": [
        {
            "id": "1",
            "poetry_data": "shdoqw djwaiood aand od sodnh asisd d ashd asidhas das das doaisdhas dsa d as diwdhw xs dw wh codfj e",
            "poet_name": "abcd efg",
            "date_time": "2021-09-02 08:32:10"
        },
        {
            "id": "2",
            "poetry_data": "updating this",
            "poet_name": "abc",
            "date_time": "2021-09-04 10:38:22"
        },
        {
            "id": "4",
            "poetry_data": "aaaaaaaaaaaa bbbbbbbbbbbbb cccccccccccccc",
            "poet_name": "abc",
            "date_time": "2021-09-02 10:11:08"
        },
        {
            "id": "5",
            "poetry_data": "aaaaaaaaaaaaaaaaaaaaa",
            "poet_name": "aa",
            "date_time": "2021-09-03 10:16:08"
        },
        {
            "id": "6",
            "poetry_data": "aaaaaaaaaaaaaaaaaaaaa",
            "poet_name": "aa",
            "date_time": "2021-09-03 10:16:22"
        },
        {
            "id": "7",
            "poetry_data": "aaaaaaaaaaaaaaaaaaaaa",
            "poet_name": "aa",
            "date_time": "2021-09-03 10:17:04"
        },
        {
            "id": "8",
            "poetry_data": "",
            "poet_name": "",
            "date_time": "2021-09-06 09:19:39"
        },
        {
            "id": "9",
            "poetry_data": "",
            "poet_name": "",
            "date_time": "2021-09-06 09:23:38"
        },
        {
            "id": "10",
            "poetry_data": "",
            "poet_name": "",
            "date_time": "2021-09-06 09:24:00"
        },
        {
            "id": "11",
            "poetry_data": "bhdjasvjguuuuuuuuuuuuuuuu",
            "poet_name": "nameisname",
            "date_time": "2021-09-06 09:29:59"
        },
        {
            "id": "12",
            "poetry_data": "bhdjasvjguuuuuuuuuuuuuuuu",
            "poet_name": "abara",
            "date_time": "2021-09-06 09:42:43"
        },
        {
            "id": "13",
            "poetry_data": "bhdjasvjguuuuuuuuuuuuuuuu",
            "poet_name": "kkkkkkkhgvghytu",
            "date_time": "2021-09-06 09:52:21"
        }
    ]
}

the second error is related to gson but i dont know how to write it correctly to parse json to gson for the structure my url returns.

thanks!

Tags:

2

Answers


  1. 0

    did you try

    myAdapter.notifyDataSetChanged()

    after this line in your main activity?

    recyclerView.setAdapter(myAdapter);
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  2. 0

    Seeing your error log and your api response json, you are parsing it wrong.
    Your response class should look like this.

    class PoetryResponse() {
   @Serializable("status")
   String status;

   @Serializable("message")
   String message;

   @Serializable("data")
   Poetry[] data;

}

    Your data object class

    class Poetry() {
 @Serializable("id")
   String id;

   @Serializable("poetry_data")
   String poetryData;

   @Serializable("poet_name")
   String poetName;
   
   @Serializable("date_time")
   String dateTime;
}

    Get response from json with below code

    PoetryResponse poetryResponse = gson.fromJson(response,PoetryResponse.class);

    Now pass the arraylist of poetry like below in your adapter

    MyAdapter myAdapter = new MyAdapter(poetryResponse.data);
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