Extract binaries line by line in JAVA without saving to a string

Question

I have the following method, but this one has a problem and it is that in a part of the file there are some special characters where the character with hexadecimal value 81(.) when the program generates the export of the file is 3F(?) and with that it damages the binary:

public static void exportbinary() {
        List<String> files = listFiles(source,1);
        System.out.println("Reviewing files to extract data");
        String registro = null;
        String contenido = "";
        for (String s : files) {
            //The name of the files to be processed is adjusted
            String ogName=s;
            System.out.println("Renaming files to extract binary data...");
            File sFile = new File(source, s);
            sFile.renameTo(new File(source,s+"ext"));
            s = s+"ext";
            
            //Start binary extraction process
            File sourceFile = new File(source, s);
            File destFile = new File(destination, ogName);
            if (destFile.exists()) {
                destFile.delete();
            }
            if (!dctmp.exists()) {
                try {
                    dctmp.createNewFile();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            Writer w = null;
            try {
                w = new BufferedWriter(new FileWriter(dctmp, true));
            } catch (IOException e1) {
                e1.printStackTrace();
            }
            System.out.println("Processing" + sourceFile + " en " + destFile);
            try (BufferedReader br = new BufferedReader(new FileReader(sourceFile))) {
                String data;
                while ((data = br.readLine()) != null) {
                    String line = data;
                    if (line.substring(0, 6).equals("924007")) {
                        // Valores binarios
                        String binarios = line.substring(585, 586 + 82);
                        line = line.substring(0, 585) + (new String(new char[83]).replace('\0', '0'))
                                + line.substring((586 + 82), line.length());
                        // TID
                        String TID = line.substring(1005, 1020);
                        registro = TID + ";" + binarios + "\n";
                        contenido = contenido + registro;
                    }
                    BufferedWriter wrtr = new BufferedWriter(new FileWriter(destFile, true));
                    wrtr.append(line + "\n");
                    wrtr.close();
                    line = null;
                }
                System.out.println("Data is added to the temporary");
                w.append(contenido);
                w.close();
                br.close();
                System.out.println("Successfully complete process");
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                sourceFile.delete();
            }
        }
    }

I did an exercise treating the file with FileInputStream() and it worked and kept the value, and it is the following code:

private void testBinary(File filename) {
   try {

     FileInputStream FileOrigin = new FileInputStream(filename);

     // Arrays
     byte[] biyeFile = new byte[(int) filename.length()];
     int[] intArray = new int[biyeFile.length];
     char[] CharArrayBit = new char[intArray.length];

     FileOrigin.read(biyeFile);

     for (int i = 0; i < biyeFile.length; i++) {
       // Converting each char into its byte equivalent
       intArray[i] = (int) Byte.toUnsignedInt(biyeFile[i]);
     }

     File temp = new File("C:/MOVIMIENTO/ebcdic/ascii/", filename.getName() + ".TMP");

     temp.createNewFile();
     FileOutputStream fileOutputStream = new FileOutputStream(temp);

     for (int j = 0; j < charArrayBit.length; ++j) {

       charArrayBit[j] = (char) intArray[j];

       try {
         if ((intArray[j] != 10) && (intArray[j] != 13)) {
           fileOutputStream.write(charArrayBit[j]);
         }
       } catch (IOException e) {
         e.printStackTrace();
       }

     }

     FileOrigin.close();
     fileOutputStream.close();
     filename.delete();
     temp.renameTo(filename);
   } catch (IOException e) {
     e.printStackTrace();
   }

 }

But I can't seem to implement the logic I made with the one that is already there and I'm getting stuck :( on how I can deal line by line in bytes. Try this Java - Read line using InputStream

The mess I have is that by using String I already lose the value String data; data = br.readLine() String line = data;

Update: The idea is that the temporary file where I am printing the TID and binary is as follows: file dc.tmp

200232133:..3....¢...€ . ...  
300232133:.....Þù...€ ....€  
400232133:ù....Þù...€ ....€ ....
etc

This is some VB.net code that I'm basing on pulling out the binary:

While POS < inputFile.Length
            While reg < rowlen
                dato1 = inputFile.ReadByte()
                POS = POS + 1
                reg = reg + 1
                dato11 = BitConverter.GetBytes(dato1)
                If (binary  = 1 And (reg > 589 And reg <= 589 + 53 + 53)) Then
                    ' here you should read two bytes and convert it to one
                    byte1 = dato1
                    ' now read the second byte
                    byte2 = inputFile.ReadByte()
                    reg = reg + 1
                    POS = POS + 1
                    final = CInt("&H" & (Chr(byte1) + Chr(byte2)))
                Else
                    dato2 = Encoding.Convert(source, DEST, dato11)
                    final = dato2(0)
                End If
                Print(1, Chr(final))
                If (reg < 7) Then 'the first positions give us the type of message
                    MTI = MTI + Chr(dato1)
                End If
                If reg = 7 Then
                    binary = 0
                    rowlen = 1400
                    If (MTI = "924007") Then ' binary
                        binary  = 1
                        rowlen = 1400 + 53
                    End If
                    MTI = ""
                End If
            End While
            POS = POS + 2
            reg = 0
        End While

Thank you.