Joining two files together

Question

I'm kinda new to Java, but i'm trying to create a program which joins 2 files together. It works fine with .txt files, but when i try to join two .wmv files, only the one it processes first will show, though the output file will have the size of the two files together. Here's my code for joining them together:
try {
                    JFileChooser location = new JFileChooser();
                    location.showDialog(this, "Save file");
                    File videoout = location.getSelectedFile();
                    OutputStream os = new FileOutputStream(videoout);
                    BufferedOutputStream out = new BufferedOutputStream(os);
                    InputStream is = null;
                    BufferedInputStream in = null;
                    ListIterator pathsIterator = paths.listIterator();
                    while(pathsIterator.hasNext()) {
                        File part = new File(pathsIterator.next().toString());
                        is = new FileInputStream(part);
                        in = new BufferedInputStream(is);
                        int line;
                        while((line = in.read()) != -1) {
                            out.write(line);
                    in.close();
                    out.close();
                    JOptionPane.showMessageDialog(this, "Done");
                } catch(IOException io) {
                    System.out.println("IO: " + io);
                }Any idea what i'm doing wrong?
Thanks

Answer 1

Just because you put 2 files in the same file doesn't mean some application can understand that it's 2 files in 1. Meaning, the player of the merged WMV can't know that there's 2 files and that it should play both back to back. You have to read the WMV files knowing the WMV format and then generate 1 file that combines the 2, which typically would include updating header information in the file. Java's I/O classes are not going to provide that sort of thing for you.