Java WS file upload service - soap

Question

I am currently working on a Java Web Service project. It is deployed on an Apache Tomcat 7 server and I need to provide a service for uploading files to the server. Also, the web service should be available to systems that may not use java. Thus, I need to make my web service universally available for all clients (i.e. C#, php etc.).
After browsing the web, I have found many solutions, but none of them does not explain how can I fulfill the aforementioned criteria. To be more specific, I have come across MTOM and Java WS Annotations that are referenced to be essential in order to specify universally accepted data stuctures, such as Java's DataHandler.
Let me post a sample code of my web service:
public class DataFileServer extends AbstractFileServer {
private int _buffer_size;
public DataFileServer() {
_buffer_size = 100000;
}
public DataFileServer(int bufferSize) {
_buffer_size = bufferSize;
}
#Override
public void uploadFile(String AbsoluteFilePath, FileObject FileInfo) {
DataHandler _handler = FileInfo.getHandler();
try {
InputStream is = _handler.getInputStream();
OutputStream os = new FileOutputStream(new File(AbsoluteFilePath +
"/" + FileInfo.getName() + "." +
FileInfo.getType()));
byte[] b = new byte[_buffer_size];
int bytesRead = 0;
while((bytesRead = is.read()) != -1) {
os.write(b, 0, bytesRead);
}
}catch(IOException e) {
e.printStackTrace();
}
}
}
The DataFileServer is the class that will to the upload operation, and the Web Service interface will be as follows:
#WebService()
public class ETL_WS {
private DataHandler _handler;
private String server_dir = "/home/user/Desktop/FileServer";
public int fileUpload(String FileName, DataHandler CsvFile) {
FileObject _file = new FileObject(FileName, CsvFile);
_handler.uploadFile(this.server_dir, _file);
return 0;
}
}
My question is, how am I going to ensure that the DataHandler object provided to my web service is going to be of the right type. Also, can I improve the security and the performance of the file upload operation with any way?
Thank you