1-) Android RMOS - yazıcıdan fiş çıkarmak

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.NFC" />

<uses-feature android:name="android.hardware.camera.autofocus" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.nfc" />



<supports-screens
    android:anyDensity="true"
    android:largeScreens="true"
    android:normalScreens="true"
    android:resizeable="true"
    android:smallScreens="true"
    android:xlargeScreens="true" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme"
    android:usesCleartextTraffic="true">

...

package com.webpos.ramazan.rmos.rmosbarpos.Printer;

import android.util.Log;

import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;
import java.nio.charset.StandardCharsets;

public class Printer {
    private String PrinterName;
    private int BosSatirSayisi;
    private String IpAddress;
    private int PortNumber;


    public String getPrinterName() {
        return PrinterName;
    }

    public void setPrinterName(String printerName) {
        PrinterName = printerName;
    }

    public int getBosSatirSayisi() {
        return BosSatirSayisi;
    }

    public void setBosSatirSayisi(int bosSatirSayisi) {
        BosSatirSayisi = bosSatirSayisi;
    }

    public String getIpAddress() {
        return IpAddress;
    }

    public void setIpAddress(String ipAddress) {
        IpAddress = ipAddress;
    }

    public int getPortNumber() {
        return PortNumber;
    }

    public void setPortNumber(int portNumber) {
        PortNumber = portNumber;
    }




    /*public void PrintString(String Document) {
        try {
            Socket sock = new Socket(IpAddress, PortNumber); //9100
            PrintWriter oStream = new PrintWriter(sock.getOutputStream());
            oStream.println(Document);
            oStream.close();
            sock.close();
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }*/

    public void PrintString(String Document) {
        try {
            //  Document.getBytes("ISO-8859-1");

            String ESC = String.valueOf((char) 27);
            String GS = String.valueOf((char) 29);

            String COMMAND = "";
            COMMAND = ESC + "@";
            COMMAND += GS + "V" + (char)1;

            String COMMAND2 = "";
            COMMAND2 = ESC + "@";
            COMMAND2 = ESC +"B"+(char)3 +(char)2;

            Document = Document + COMMAND + " " +COMMAND2 ;


            Socket sock = new Socket(IpAddress, PortNumber); //9100
            PrintWriter  pstream = new PrintWriter(new OutputStreamWriter(sock.getOutputStream(), StandardCharsets.ISO_8859_1),true);
            //pstream.format(new Locale("tr","TR"),"windows-1254",null);

            Log.d("Printer",Document);

            pstream.println(Document);
            pstream.close();
            sock.close();

        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

-------------------

public void SiparisPrint(int Fisno) {
    try {
        ArrayList<Printer> printers = (ArrayList<Printer>) getSiparisPrinter(Fisno);
        for (Printer mprinter : printers)
        {
            StringBuilder sb = new StringBuilder();

            sb.append(".");
            sb.append(System.getProperty("line.separator"));
            sb.append("      SIPARIS FISI     ");
            sb.append(System.getProperty("line.separator"));
            sb.append(".");
            sb.append(System.getProperty("line.separator"));
            sb.append("Departman : " );
            sb.append(System.getProperty("line.separator"));
            sb.append("Tarih:" );
            sb.append(System.getProperty("line.separator"));
            sb.append("Saat :" );
            mprinter.PrintString(sb.toString());
        }
    } catch (Exception e) {
        throw new RuntimeException("FisPrDAL -> "+e.getMessage());
    }
}

-------------------------------

private List<Printer> getSiparisPrinter(int Fisno) {
    ArrayList<Printer> mList = new ArrayList<Printer>();
    Printer s = new Printer();
    s.setPrinterName("üst-icecek");
    s.setBosSatirSayisi(4);
    s.setIpAddress("192.168.2.240");
    s.setPortNumber(9100);
    mList.add(s);
    return mList;
}

---------------

@Override
protected void onCreate(Bundle savedInstanceState) {
    StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
    StrictMode.setThreadPolicy(policy);
    super.onCreate(savedInstanceState);