SOAP WS attachment issue

Question

I'm facing an issue with a Java SOAP web service that receives an attachment and saves its content to a local file. The problem is that even though the file is being saved, the resulting content is not readable, despite it being a text file.

Here's the code I'm using:

@WebMethod
public String scan(@WebParam(name = "peticion") String peticion,
    @WebParam(name = "fichero") DataHandler fichero) throws RemoteException {

    String tempFolderPath = "/path/to/my/temporary/directory";
    File tempFile = new File(tempFolderPath + File.separator + "temp.txt");
    try (InputStream input = fichero.getInputStream();
         OutputStream output = new FileOutputStream(tempFile);) {
        byte[] b = new byte[100000];
        int bytesRead = 0;
        while ((bytesRead = input.read(b)) != -1) {
            output.write(b, 0, bytesRead);
        }
        // Additional logic
    } catch (Exception e) {
        e.printStackTrace();
    }

    try {
        //return getEjb().scan(peticion, fichero);
        return "scanned";
    } catch (final Exception e) {
        LOGGER.error(ERROR_PROCESSING, e);
        if (!(e instanceof PeticionException)) {
            throw new RemoteException("Error processing the request");
        } else {
            throw new RemoteException(e.getMessage(), e);
        }
    }
}

When I send a SOAP request that includes a text file, the file gets saved to the specified temporary directory, but the content is not readable. Can someone help me understand why this is happening and how I can ensure that the file is saved in a readable format?

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ws="http://msps/antivirus/ws">
   <soapenv:Header/>
   <soapenv:Body>
      <ws:scan>
         <peticion><![CDATA[<peticion xmlns="http://xml.antivirus.msps/Peticion"><acceso><id_aplicacion>APP</id_aplicacion></acceso><fichero><nombre>Prueba.txt</nombre></fichero></peticion>]]></peticion>
         <fichero>cid:Prueba.txt</fichero>
      </ws:scan>
   </soapenv:Body>
</soapenv:Envelope>

Any guidance you can provide would be appreciated. Thanks.