MainActivity.java

/*
* Copyright (c) 2018 Faruk Ahmed
* License Under MIT
* Not use for commercial perpose
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*/

public class MainActivity extends AppCompatActivity {

    private Button getApiBtn, postApiBtn;
    private TextView resultTextView;
    RequestQueue requestQueue;
    private static final String TAG = MainActivity.class.getSimpleName();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        resultTextView = (TextView) findViewById(R.id.resultTextView);
        getApiBtn = (Button) findViewById(R.id.getApiBtn);
        postApiBtn = (Button)findViewById(R.id.postApiBtn);

        // RequestQueue For Handle Network Request
        RequestQueue requestQueue = Volley.newRequestQueue(getApplicationContext());
        //Click Listner for GET JSONObject
        getApiBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                getData();
            }
        });
        //Click Listner for POST JSONObject
        postApiBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                postData();
            }
        });
    }

    // Post Request For JSONObject 
    public void postData() {
        RequestQueue requestQueue = Volley.newRequestQueue(getApplicationContext());
        JSONObject object = new JSONObject();
        try {
            //input your API parameters
            object.put("parameter","value");
            object.put("parameter","value");
        } catch (JSONException e) {
            e.printStackTrace();
        }
        // Enter the correct url for your api service site
        String url = getResources().getString(R.string.url);
        JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.POST, url, object,
                new Response.Listener<JSONObject>() {
                    @Override
                    public void onResponse(JSONObject response) {
                        resultTextView.setText("String Response : "+ response.toString());
                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                resultTextView.setText("Error getting response");
            }
        });
        requestQueue.add(jsonObjectRequest);
    }

    // Get Request For JSONObject 
    public void getData(){
        RequestQueue requestQueue = Volley.newRequestQueue(getApplicationContext());
        try {
            String url = getResources().getString(R.string.url);
            JSONObject object = new JSONObject();
            JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
                @Override
                public void onResponse(JSONObject response) {
                    resultTextView.setText("Resposne : " + response.toString());
                    Toast.makeText(getApplicationContext(), "I am OK !" + response.toString(), Toast.LENGTH_LONG).show();
                }
            }, new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    Toast.makeText(getApplicationContext(), "Error", Toast.LENGTH_LONG).show();
                }
            });
            requestQueue.add(jsonObjectRequest);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}