login xml

login.xml

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@color/colorPrimary"
    android:fitsSystemWindows="true">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:focusable="true"
        android:focusableInTouchMode="true"
        android:paddingTop="56dp"
        android:paddingLeft="24dp"
        android:paddingRight="24dp">

        <ImageView android:src="@android:drawable/ic_menu_gallery"
            android:layout_width="130dp"
            android:layout_height="130dp"
            android:layout_marginBottom="24dp"
            android:layout_gravity="center_horizontal" />

        <!-- Email Label -->
        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:layout_marginBottom="8dp">
            <EditText android:id="@+id/input_email"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:inputType="textEmailAddress"
                android:hint="Email" />
        </android.support.design.widget.TextInputLayout>

        <!-- Password Label -->
        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:layout_marginBottom="8dp">
            <EditText android:id="@+id/input_password"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:inputType="textPassword"
                android:hint="Password"/>
        </android.support.design.widget.TextInputLayout>

        <android.support.v7.widget.AppCompatButton
            android:id="@+id/btn_login"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="24dp"
            android:layout_marginBottom="24dp"
            android:padding="12dp"
            android:text="Login"/>

        <TextView android:id="@+id/link_signup"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="24dp"
            android:text="No account yet? Create one"
            android:gravity="center"
            android:textSize="16dip"/>

    </LinearLayout>
</ScrollView>

                                                        ///////Java Code/////////




import android.app.ProgressDialog;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import android.util.Patterns;
import android.widget.EditText;
import android.widget.Toast;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;
import org.json.JSONException;
import org.json.JSONObject;
import in.prayaninfotech.mynotes.NotesActivity;
import in.prayaninfotech.mynotes.R;

public class LoginActivity extends AppCompatActivity {

    private EditText input_email, input_password;
    private ProgressDialog progressDialog;
    private String email = "";
    private String password = "";
    private String TAG=LoginActivity.class.getSimpleName();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        progressDialog = new ProgressDialog(this);
        progressDialog.setMessage("Please wait..");
        input_email = findViewById(R.id.input_email);
        input_password = findViewById(R.id.input_password);
        findViewById(R.id.btn_login).setOnClickListener(view -> {
            if (validated()) {
                onclick();
            }
        });
    }

    @Override
    protected void onPause() {
        super.onPause();
        if (progressDialog != null && progressDialog.isShowing()) {
            progressDialog.dismiss();
        }
    }

    boolean validated() {
        email = input_email.getText().toString();
        password = input_password.getText().toString();
        if (TextUtils.isEmpty(email) || !Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
            Toast.makeText(this, "Please enter a valid email", Toast.LENGTH_SHORT).show();

            return false;
        }
        if (TextUtils.isEmpty(password)) {
            Toast.makeText(this, "Please enter password", Toast.LENGTH_SHORT).show();
            return false;
        }

        return true;
    }

    private void onclick() {
        if (progressDialog != null) {
            progressDialog.show();
        }

        JSONObject jsonObject = new JSONObject();
        try {
            jsonObject.put("email", email);
            jsonObject.put("password", password);
        } catch (JSONException e) {
            e.printStackTrace();
        }


        JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.POST,
                Constants.URL, jsonObject, response -> {
            Log.d(TAG, response.toString());
            if (progressDialog != null && progressDialog.isShowing()) {
                progressDialog.dismiss();
            }
            startActivity(new Intent(LoginActivity.this, NotesActivity.class).putExtra(Constants.KEY_EXTRA, String.valueOf(response)));
            finish();

        }, error -> {
            Log.d(TAG, error.toString());
            if (progressDialog != null && progressDialog.isShowing()) {
                progressDialog.dismiss();
            }
        });

        RequestQueue requestQueue = Volley.newRequestQueue(this);
        requestQueue.add(jsonObjReq);
    }
}