import org.json.JSONException;
import org.json.JSONObject;

import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.AsyncHttpResponseHandler;
import com.loopj.android.http.RequestParams;



import cz.msebera.android.httpclient.Header;

public class LoginUser extends AppCompatActivity
{
// Progress Dialog Object
ProgressDialog prgDialog;
// Error Msg TextView Object
TextView errorMsg;
// Email Edit View Object
EditText emailET;
// Passwprd Edit View Object
EditText pwdET;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.content_main);
    // Find Error Msg Text View control by ID
    errorMsg = (TextView) findViewById(R.id.login_error);
    // Find Email Edit View control by ID
    emailET = (EditText) findViewById(R.id.edtemail);
    // Find Password Edit View control by ID
    pwdET = (EditText) findViewById(R.id.edtpass);
    // Instantiate Progress Dialog object
    prgDialog = new ProgressDialog(this);
    // Set Progress Dialog Text
    prgDialog.setMessage("Please wait...");
    // Set Cancelable as False
    prgDialog.setCancelable(false);
}




/**
 * Method gets triggered when Login button is clicked
 *
 * @param view
 */
public void loginUser(View view) {
    // Get Email Edit View Value
    String email = emailET.getText().toString();
    // Get Password Edit View Value
    String password = pwdET.getText().toString();

    // Instantiate Http Request Param Object
    RequestParams params = new RequestParams();

    // When Email Edit View and Password Edit View have values other than Null
    if (Utility.isNotNull(email) && Utility.isNotNull(password)) {
        // When Email entered is Valid
        if (Utility.validate(email)) {
            // Put Http parameter username with value of Email Edit         View control
            params.put("Username", email);
            // Put Http parameter password with value of Password Edit Value control
            params.put("Pass", password);
            // Invoke RESTful Web Service with Http parameters
            Login(params);
        }
        // When Email is invalid
        else {
            Toast.makeText(getApplicationContext(), "Please enter valid email address with no spaces!", Toast.LENGTH_LONG).show();
        }
    } else {
        Toast.makeText(getApplicationContext(), "Please fill the form, don't leave any field blank!", Toast.LENGTH_LONG).show();
    }


}



/**
 * Method that performs RESTful webservice invocations
 *
 * @param params
 */
public void Login(RequestParams params){
    // Show Progress Dialog
    prgDialog.show();

    // Make RESTful webservice call using AsyncHttpClient object
    final AsyncHttpClient client = new AsyncHttpClient();
    client.get("MY URL IS HERE", params, new AsyncHttpResponseHandler() {



        // When the response returned by REST has Http response code '200'
        @Override
        public void onSuccess(int statusCode, Header[] headers, byte[] responseBody)
        {

            // Hide Progress Dialog
            prgDialog.hide();
            try {

                JSONObject obj = new JSONObject(new String(responseBody));

                // When the JSON response has status boolean value assigned with true
                if (obj.getBoolean("status")) {
                    Toast.makeText(getApplicationContext(), "You are successfully logged in!", Toast.LENGTH_LONG).show();
                    // Navigate to Home screen
                    navigatetoMyLocationActivity();
                }
                // Else display error message
                else {
                    errorMsg.setText(obj.getString("error_msg"));
                    Toast.makeText(getApplicationContext(),     obj.getString("error_msg"), Toast.LENGTH_LONG).show();
                }
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                Toast.makeText(getApplicationContext(), "Error Occurred [Server's JSON response might be invalid]!", Toast.LENGTH_LONG).show();
                e.printStackTrace();

            }

        }


        // When the response returned by REST has Http response code other than '200'
        @Override
        public void onFailure(int statusCode, Header[] headers, byte[] responseBody, Throwable error) {
            // Hide Progress Dialog
            prgDialog.hide();
            // When Http response code is '404'
            if (statusCode == 404) {
                Toast.makeText(getApplicationContext(), "Requested resource not found", Toast.LENGTH_LONG).show();
            }
            // When Http response code is '500'
            else if (statusCode == 500) {
                Toast.makeText(getApplicationContext(), "Something went wrong at server end", Toast.LENGTH_LONG).show();
            }
            // When Http response code other than 404, 500
            else {
                Toast.makeText(getApplicationContext(), "Unexpected Error occurred! [Most common Error: Device might not be connected to Internet or remote server is not up and running]", Toast.LENGTH_LONG).show();
            }

        }
    });
}




/**
 * Method which navigates from Login Activity to Home Activity
 */
public void navigatetoMyLocationActivity(){
    Intent homeIntent = new Intent(getApplicationContext(),MyLocation.class);
    homeIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    startActivity(homeIntent);
}

public class LoginUserDTO
{
private String UserName;
private String Pass;


public LoginUserDTO(String UserName, String Pass)
{
this.UserName = UserName;
this.Pass = Pass;

}


public String getUsername()
{
    return UserName;
}

public void setUserName(String UserName)
{
    this.UserName = UserName;
}



public String getPass()
{
    return Pass;
}

public void setPass(String Pass)
{
    this.Pass = Pass;
}

<uses-permission android:name="android.permission.INTERNET" />