MainActivity.java

package com.nophp.attendancescanner;

import android.app.Activity;
import android.content.Intent;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffColorFilter;
import android.graphics.drawable.Drawable;
import android.media.Image;
import android.media.MediaPlayer;
import android.os.StrictMode;
import android.support.annotation.Nullable;
import android.support.v4.content.ContextCompat;
import android.support.v4.graphics.drawable.DrawableCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import com.google.zxing.Result;
import com.google.zxing.ResultPoint;
import com.google.zxing.client.android.BeepManager;
import com.google.zxing.integration.android.IntentIntegrator;
import com.google.zxing.integration.android.IntentResult;
import com.journeyapps.barcodescanner.BarcodeCallback;
import com.journeyapps.barcodescanner.BarcodeResult;
import com.journeyapps.barcodescanner.BarcodeView;
import com.journeyapps.barcodescanner.CaptureManager;
import com.journeyapps.barcodescanner.DecoratedBarcodeView;
import com.journeyapps.barcodescanner.camera.CameraSettings;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.Scanner;

public class MainActivity extends AppCompatActivity
{

    public BeepManager beep;
    public static android.support.v4.app.FragmentManager fragman;
    private DecoratedBarcodeView barcodeView = null;

    CaptureManager capture;

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

        View decorView = getWindow().getDecorView();
        int uiOptions = View.SYSTEM_UI_FLAG_FULLSCREEN;
        decorView.setSystemUiVisibility(uiOptions);

        barcodeView = (DecoratedBarcodeView) findViewById(R.id.barcode_scanner);
        barcodeView.getViewFinder().setVisibility(View.VISIBLE);
        barcodeView.setStatusText("");

        CameraSettings cameraSettings = new CameraSettings();
        cameraSettings.setRequestedCameraId(1);
        barcodeView.getBarcodeView().setCameraSettings(cameraSettings);

        BarcodeCallback callback = new BarcodeCallback()
        {
            @Override
            public void barcodeResult(BarcodeResult result)
            {
                if (result.getText() != null) {
                    scanner(result);
                }
            }

            @Override
            public void possibleResultPoints(List<ResultPoint> resultPoints)
            {

            }
        };

        barcodeView.decodeContinuous(callback);

        //setContentView(barcodeView);
        if (android.os.Build.VERSION.SDK_INT > 9)
        {
            StrictMode.ThreadPolicy policy = new
                    StrictMode.ThreadPolicy.Builder().permitAll().build();
            StrictMode.setThreadPolicy(policy);
        }
    }

    @Override
    protected void onResume() {
        super.onResume();
        barcodeView.resume();
    }

    @Override
    protected void onPause() {
        super.onPause();
        barcodeView.pause();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        capture.onDestroy();
    }


    protected void scanner(BarcodeResult result)
    {
        if (result != null)
        {
            if (result.getText() == null)
            {
                Toast.makeText(this, "Scanning Cancelled", Toast.LENGTH_LONG).show();
            }
            else
            {
                String text = "https://ziemni.me/rwp/scanner.php?qr=" + result.getText();
                System.out.println(text);

                String textReturn = readWeb(text.toLowerCase());
                String errorCheckedText = errorCheck(textReturn);
                if (errorCheckedText == "Success!")
                {
                    MediaPlayer mediaPlayer = MediaPlayer.create(this, R.raw.beep);
                    mediaPlayer.start();
                    ImageView image = (ImageView)findViewById(R.id.circle);
                    image.setImageResource(R.drawable.green);
                }
                else if (errorCheckedText == "Late!")
                {
                    ImageView image = (ImageView)findViewById(R.id.circle);

                    image.setImageResource(R.drawable.orange);
                }
                else
                {
                    ImageView image = (ImageView)findViewById(R.id.circle);

                    image.setImageResource(R.drawable.red);
                }
                Toast.makeText(this, errorCheckedText, Toast.LENGTH_LONG).show();
            }
        }
    }

    public String errorCheck(String hashed)
    {

        String segments[] = hashed.split("\"");

        String text = segments[segments.length - 3];
        System.out.println(text);

        String toastMessage = "?";

        if (text.contains("0"))
        {
            toastMessage = "Success!";
        }

        else if (text.contains("1"))
        {
            toastMessage = "Error 1: Incorrect hash";
        }

        else if (text.contains("2"))
        {
            toastMessage = "Error 2: Scanner ID is not an integer";
        }

        else if (text.contains("3"))
        {
            toastMessage = "Error 3: Issue reaching database, try again!";
        }

        else if (text.contains("4"))
        {
            toastMessage = "Error 4: QR code does not match";
        }

        else if (text.contains("5"))
        {
            toastMessage = "Error 5: QR code expired";
        }
        else if (text == "FAIL")
        {
            toastMessage = "Error A1: Failure to establish internet connection";
        }

        return toastMessage;
    }

    public String readWeb(String text)
    {
        try (Scanner scanner = new Scanner(new URL(text).openStream(), StandardCharsets.UTF_8.toString()))
        {
            scanner.useDelimiter("\\A");
            return scanner.hasNext() ? scanner.next() : "";
        }
        catch (MalformedURLException e)
        {
            System.out.println("Malformed URL: " + e.getMessage());
        }
        catch (IOException e)
        {
            System.out.println("I/O Error: " + e.getMessage());
        }
        return "FAIL";
    }

}