Code below demonstrates how read and write a file using an applet.
Java Code:
	int arrlen = 10000;
	byte[] infile = new byte[arrlen];
	Frame parent = new Frame();
	FileDialog fd = new FileDialog(parent, "Please choose a file:",
	           FileDialog.LOAD);
	fd.show();
	String selectedItem = fd.getFile();
	if (selectedItem == null) {
		// no file selected
	} else {
		File ffile = new File( fd.getDirectory() + File.separator +
		        fd.getFile());
		// read the file
		System.out.println("reading file " + fd.getDirectory() +
		                         File.separator + fd.getFile() );
		try {
			FileInputStream fis = new FileInputStream(ffile); 
			BufferedInputStream bis = new BufferedInputStream(fis);
			DataInputStream dis = new DataInputStream(bis);
			try {
				int filelength = dis.read(infile);
				String filestring = new String(infile, 0, filelength);
				System.out.println("FILE CONTENT=" + filestring);
			} catch(IOException iox) {
				System.out.println("File read error...");
				iox.printStackTrace();
			}
		} catch (FileNotFoundException fnf) {
			System.out.println("File not found...");
			fnf.printStackTrace();
		}
	}