code

 private GoogleApiClient client;

    private EditText username;
    private EditText password;
    private EditText email;
    private EditText signup;
    private EditText name;

    private Button btnSignup;
    private ProgressBar pb;
    private int mStatusCode;


    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_signup);
        pb = (ProgressBar) findViewById(R.id.progressbar);


        getSupportActionBar().setTitle((Html.fromHtml("<font color=\"#3e3e3e\">Sign Up</font>")));
        getSupportActionBar().setBackgroundDrawable(new ColorDrawable(0xffffff));










            getSupportActionBar().setDisplayHomeAsUpEnabled(true);

//        final Drawable upArrow = getResources().getDrawable(R.drawable.abc_ic_ab_back_mtrl_am_alpha);
//        upArrow.setColorFilter(Color.parseColor("#FF3e3e3e"), PorterDuff.Mode.SRC_ATOP);
//        getSupportActionBar().setHomeAsUpIndicator(upArrow);



            username = (EditText) findViewById(R.id.edit);
            password = (EditText) findViewById(R.id.edit1);

            email= (EditText) findViewById(R.id.edit2);
            name =(EditText)findViewById(R.id.edit3);
            btnSignup = (Button) findViewById(R.id.btn);
            pb = (ProgressBar) findViewById(R.id.progressbar);

            btnSignup.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    final String usernameTxt = username.getText().toString();
                    final String passwordText = password.getText().toString();
                    final String emailText = email.getText().toString();
                    final String nameText = name.getText().toString();

                    if (!usernameTxt.matches("[a-zA-Z0-9.\\-_]{3,}")) {
                        View parentLayout = findViewById(android.R.id.content);
                        Snackbar sb = Snackbar.make(parentLayout, "User name is invalid", Snackbar.LENGTH_LONG)
                                .setAction("CLOSE", new View.OnClickListener() {
                                    @Override
                                    public void onClick(View view) {

                                    }
                                })
                                .setActionTextColor(getResources().getColor(android.R.color.white ));
                        View sbView = sb.getView();
                        sbView.setBackgroundColor(ContextCompat.getColor(SignupActivity.this, R.color.Pink));
                        sb.show();
//                            .setActionTextColor(getResources().getColor(android.R.color.holo_red_light ))
//                            .show();


//                    Toast.makeText(SignUp.this, "Username is invalid", Toast.LENGTH_LONG).show();
                        return;
                    }

                    if (!emailText.matches("^[A-Za-z0-9+_.-]+@(.+)$")) {
                        View parentLayout = findViewById(android.R.id.content);
                        Snackbar sb = Snackbar.make(parentLayout, "invalid email address", Snackbar.LENGTH_LONG)
                                .setAction("", new View.OnClickListener() {
                                    @Override
                                    public void onClick(View view) {

                                    }
                                })
                                .setActionTextColor(getResources().getColor(android.R.color.white ));
                        View sbView = sb.getView();
                        sbView.setBackgroundColor(ContextCompat.getColor(SignupActivity.this, R.color.Pink));
                        sb.show();
//                            .setActionTextColor(getResources().getColor(android.R.color.holo_red_light ))
//                            .show();



//                    Toast.makeText(SignUp.this, "Invalid email address", Toast.LENGTH_LONG).show();
//                    return;

                    }
                    RequestQueue requestQueue = Volley.newRequestQueue(getApplicationContext());
                    StringRequest request = new StringRequest(Request.Method.POST, "http://loupe.kulchan.com/api/signup", new Response.Listener<String>() {
                        @Override
                        public void onResponse(String response) {
                            Log.v("#status", response);

                            pb.setVisibility(View.GONE);

                            Intent intent = new Intent(SignupActivity.this, HomeActivity.class);
                            startActivity(intent);
                            finish();

                        }
                    }, new Response.ErrorListener() {
                        @Override
                        public void onErrorResponse(VolleyError error) {

                            if(null != error){
                                Log.v("#status",error.getMessage());
                                try {
                                    JSONObject obj = new JSONObject(error.getMessage().toString());

//                                Toast.makeText(SignUp.this, obj.getString("error"), Toast.LENGTH_LONG).show();
                                    View parentLayout = findViewById(android.R.id.content);
                                    Snackbar sb = Snackbar.make(parentLayout, obj.getString("error"), Snackbar.LENGTH_LONG)
                                            .setAction("", new View.OnClickListener() {
                                                @Override
                                                public void onClick(View view) {

                                                }
                                            })
                                            .setActionTextColor(getResources().getColor(android.R.color.white ));
                                    View sbView = sb.getView();
                                    sbView.setBackgroundColor(ContextCompat.getColor(SignupActivity.this, R.color.Pink));
                                    sb.show();

                                } catch (JSONException e) {
                                    e.printStackTrace();
                                }
                            }
                        }
                    }) {
                        @Override

                        protected Map<String, String> getParams() {
                            Map<String, String> params = new HashMap<String, String>();
                            params.put("username", usernameTxt);
                            params.put("name", nameText);
                            params.put("password", passwordText);
                            params.put("email", emailText);

                            Log.v("#status", params.toString());
                            return params;


                        }

                        @Override
                        protected VolleyError parseNetworkError(VolleyError volleyError) {
                            String json;
                            if (volleyError.networkResponse != null && volleyError.networkResponse.data != null) {
                                try {
                                    json = new String(volleyError.networkResponse.data,
                                            HttpHeaderParser.parseCharset(volleyError.networkResponse.headers));
                                } catch (UnsupportedEncodingException e) {
                                    return new VolleyError(e.getMessage());
                                }
                                return new VolleyError(json);
                            }
                            return volleyError;
                        }
                    };


                    requestQueue.add(request);
                    requestQueue.start();

                }
            });
        }
    }