FileInputStream fis = new FileInputStream("a.jpg");
ps.setBlob(4,fis);

Blob photo = rs.getBlob("photo");
InputStream bis = photo.getBinaryStream();
FileOutputStream fos = new FileOutputStream("a.jpg");
byte[] buf = new byte[1024];
int len=0;
while ((len=bis.read(buf))!=-1){
    fos.write(buf,0,len);
}