PostresultActivity.java

package id.co.kopkarbsm.votingsystem;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.webkit.JavascriptInterface;
import android.webkit.WebChromeClient;
import android.webkit.WebResourceRequest;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.TextView;
import android.widget.Toast;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Method;
import java.net.URLEncoder;
import java.util.Set;
import java.util.UUID;

public class PostresultActivity extends AppCompatActivity {

    TextView textView;
    WebView webView;
    BluetoothAdapter bluetoothAdapter;
    BluetoothSocket socket;
    BluetoothDevice bluetoothDevice;
    OutputStream outputStream;
    InputStream inputStream;
    Thread workerThread;
    byte[] readBuffer;
    int readBufferPosition;
    volatile boolean stopWorker;
    String value = "";

    @Override
    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.postresult_activity);
        textView = findViewById(R.id.textView);
        webView = findViewById(R.id.webView);
        WebSettings webSettings = webView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        webView.addJavascriptInterface(new MyJavascript(PostresultActivity.this),"androidJS");
        webView.setWebViewClient(new webCallBack());
        webView.setWebChromeClient(new webChromeClientCallback());

        webView.setVisibility(View.INVISIBLE);
        textView.setText("BEFORE POST RESULT");


        if(getIntent().getExtras()!=null)
        {
            textView.setText("POST RESULT");
            textView.setText(getIntent().getExtras().getString("code"));
             String code=getIntent().getExtras().getString("code");
            String postData = "code=" + URLEncoder.encode(code);
            webView.postUrl(CustomString.url_aktivasi,postData.getBytes());
            webView.setVisibility(View.VISIBLE);
        }

    }

    private class webCallBack extends WebViewClient
    {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request)
        {
            return super.shouldOverrideUrlLoading(view,request);
        }
        @Override
        public void onPageFinished(WebView view, String url)
        {
            super.onPageFinished(view,url);
        }
    }

    private class webChromeClientCallback extends WebChromeClient {
        @Override
        public void onReceivedTitle(WebView webView,String title){
            super.onReceivedTitle(webView,title);
        }
    }

    public class MyJavascript {
        Context mContext;
        MyJavascript(Context context) {
            mContext = context;
        }
        @JavascriptInterface
        public void loadMainActivity(String url) {
            Toast.makeText(PostresultActivity.this,"Reload", Toast.LENGTH_SHORT).show();
            Intent intent=new Intent(mContext,MainActivity.class);
            intent.putExtra("url",url);
            startActivity(intent);
            finish();
        }
        @JavascriptInterface
        public void print(String textPrint,String namaPrinter) {
            Toast.makeText(PostresultActivity.this,"PRINTING: "+textPrint,Toast.LENGTH_LONG).show();
            IntentPrint(textPrint,namaPrinter);
        }
    }

    public void IntentPrint(String txtvalue,String namaPrinter)
    {
        byte[] buffer = txtvalue.getBytes();
        byte[] PrintHeader = { (byte) 0xAA, 0x55,2,0 };
        PrintHeader[3]=(byte) buffer.length;
        InitPrinter(namaPrinter);
        if(PrintHeader.length>128)
        {
            value+="\nValue is more than 128 size\n";
            Toast.makeText(PostresultActivity.this, value, Toast.LENGTH_LONG).show();
        }
        else
        {
            try
            {

                outputStream.write(txtvalue.getBytes());
                outputStream.close();
                socket.close();
            }
            catch(Exception ex)
            {
                value+=ex.toString()+ "\n" +"Excep IntentPrint \n";
                Toast.makeText(PostresultActivity.this, value, Toast.LENGTH_LONG).show();
            }
        }
    }
    public void InitPrinter(String namaPrinter)
    {
        bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        try
        {
            if(!bluetoothAdapter.isEnabled())
            {
                Intent enableBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
                startActivityForResult(enableBluetooth, 0);
            }

            Set<BluetoothDevice> pairedDevices = bluetoothAdapter.getBondedDevices();

            if(pairedDevices.size() > 0)
            {
                for(BluetoothDevice device : pairedDevices)
                {
                    if(device.getName().equals(namaPrinter)) //Note, you will need to change this to match the name of your device
                    {
                        bluetoothDevice = device;
                        Toast.makeText(this, "DEVICE FOUND: "+device.getName()+" "+bluetoothDevice, Toast.LENGTH_LONG).show();
                        break;
                    }
                }

                UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); //Standard SerialPortService ID
                Method m = bluetoothDevice.getClass().getMethod("createRfcommSocket", new Class[]{int.class});
                socket = (BluetoothSocket) m.invoke(bluetoothDevice, 1);
                bluetoothAdapter.cancelDiscovery();
                socket.connect();
                outputStream = socket.getOutputStream();
                inputStream = socket.getInputStream();
                beginListenForData();
            }
            else
            {
                value+="No Devices found";
                Toast.makeText(PostresultActivity.this, value, Toast.LENGTH_LONG).show();
                return;
            }
        }
        catch(Exception ex)
        {
            value+=ex.toString()+ "\n" +" InitPrinter \n";
            Toast.makeText(PostresultActivity.this, value, Toast.LENGTH_LONG).show();
        }
    }
    void beginListenForData() {
        try {
            final Handler handler = new Handler();

            // this is the ASCII code for a newline character
            final byte delimiter = 10;

            stopWorker = false;
            readBufferPosition = 0;
            readBuffer = new byte[1024];

            workerThread = new Thread(new Runnable() {
                public void run() {

                    while (!Thread.currentThread().isInterrupted() && !stopWorker) {

                        try {

                            int bytesAvailable = inputStream.available();

                            if (bytesAvailable > 0) {

                                byte[] packetBytes = new byte[bytesAvailable];
                                inputStream.read(packetBytes);

                                for (int i = 0; i < bytesAvailable; i++) {

                                    byte b = packetBytes[i];
                                    if (b == delimiter) {

                                        byte[] encodedBytes = new byte[readBufferPosition];
                                        System.arraycopy(
                                                readBuffer, 0,
                                                encodedBytes, 0,
                                                encodedBytes.length
                                        );

                                        // specify US-ASCII encoding
                                        final String data = new String(encodedBytes, "US-ASCII");
                                        readBufferPosition = 0;

                                        // tell the user data were sent to bluetooth printer device
                                        handler.post(new Runnable() {
                                            public void run() {
                                                Log.d("e", data);
                                            }
                                        });

                                    } else {
                                        readBuffer[readBufferPosition++] = b;
                                    }
                                }
                            }
                        } catch (IOException ex) {
                            stopWorker = true;
                        }
                    }
                }
            });

            workerThread.start();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }


}