gunakan library :
implementation 'com.android.volley:volley:1.1.0'



Kemudian ketika tombol login di klik, panggail fungsi di bawah ini. cara panggil cuman ketik : Login();
public void Login(){
    EditText username = (EditText)findViewById(R.id.username);
    EditText    password = (EditText)findViewById(R.id.password);
        StringRequest postRequest = new StringRequest(Request.Method.POST, 'https://xerjo.com/xerjain/home/login',
                new Response.Listener<String>()
                {
                    @Override
                    public void onResponse(String response) {
                        try {
                            JSONObject data = new JSONObject(response);
                            if(data.getString("status").equals("success")){
                                JSONObject result = new JSONObject(data.getString("data"));
                                //Login berhasil

                                /**** SIMPAN DATA USERNAME KE TELPON ****/
                                pref = getSharedPreferences("mysharepref", MODE_PRIVATE);
                                SharedPreferences.Editor editor = pref.edit();
                                editor.putString("username", result.getString("user_real_name").toString());

                                Toast.makeText(getApplication(),"Berhasil masuk.",Toast.LENGTH_LONG).show();
                                finish();
                                Intent intentLog = new Intent(getApplicationContext(), MainActivity.class);
                                startActivity(intentLog);
                            }else{
                                Toast.makeText(getApplication(),data.getString("message"),Toast.LENGTH_LONG).show();
                            }
                        } catch (JSONException e) {
                            Toast.makeText(getApplication(),e.getMessage(),Toast.LENGTH_LONG).show();
                        }
                    }
                },
                new Response.ErrorListener()
                {
                    @Override
                    public void onErrorResponse(VolleyError volleyError) {
                        String message = null;
                        if (volleyError instanceof NetworkError) {
                            message = "Tidak dapat terhubung ke internet... Cek koneksi internet anda!";
                        } else if (volleyError instanceof ServerError) {
                            message = "Tidak dapat menemukan server!";
                        } else if (volleyError instanceof AuthFailureError) {
                            message = "Tidak dapat terhubung ke internet... Cek koneksi internet anda!";
                        } else if (volleyError instanceof ParseError) {
                            message = "Parsing data gagal! Cobalah beberapa saat lagi!";
                        } else if (volleyError instanceof NoConnectionError) {
                            message = "Tidak dapat terhubung ke internet... Cek koneksi internet anda!";
                        } else if (volleyError instanceof TimeoutError) {
                            message = "Koneksi TimeOut! Internet anda lemah, silahkan beralih ke wifi.";
                        }
                        Toast.makeText(getApplication(),message,Toast.LENGTH_LONG).show();
                    }
                }
        ) {
            @Override
            public Map<String, String> getHeaders() {
                Map<String, String> mHeaders = new ArrayMap<String, String>();
                mHeaders.put("X-API-KEY", Globals.API_KEY);
                return mHeaders;
            }

            @Override
            protected Map<String, String> getParams()
            {
                Map<String, String>  params = new HashMap<String, String>();
                params.put("username", username.getText().toString());
                params.put("password", password.getText().toString());
                return params;
            }
        };
        Volley.newRequestQueue(getApplicationContext()).add(postRequest);
    }