Read input stream

Question

My function tried to parse a inputstream(xml format) but I keep getting exception: Exception org.xml.sax.SAXParseException: The root element is required in a well-formed document. I checked my XML format, it looks correct. Is there a way I can print out the input stream but still be able to parse it later with the sam input stream? Thanks.
public static final Document getDOMTree(InputStream input) throws Exception
try
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
     DocumentBuilder builder = factory.newDocumentBuilder();
     Document doc = builder.parse(input);
return doc;
} catch(DOMException de) {
System.out.println("parse error " +de);
     throw new Exception(de.toString());
} catch(Exception e)
System.out.println("Exception " +e);
     throw new Exception(e.toString());
}

Answer 1

Here's a class that I use for viewing outputstreams in a similar way - you can either adjust it to work as an input stream, or do a quick web search on TeeInputStream - I suspect you'll find some code.
Cheers,
- K
* Copyright (c) 2001 Matthew Feldt. All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided the copyright notice above is
* retained.
* THIS SOFTWARE IS PROVIDED ''AS IS'' AND WITHOUT ANY EXPRESSED OR
* IMPLIED WARRANTIES.
* TeeOutputStream.java
* Java Examples In A Nutshell Copyright (c) 2000 David Flanagan
* Exercise 3-7:
* Write a subclass of OutputStream named TeeOutputStream that acts like a T
* joint in a pipe; the stream sends its output to two different output streams,
* specified when the TeeOutputStream is created. Write a simple test program
* that uses two TeeOutputStream objects to send text read from System.in to
* System.out and to two different test files.
* @author Matthew Feldt <[email protected]>
* @version 1.0, 02/12/2001 08:23
import java.io.*;
public class TeeOutputStream extends OutputStream {
    OutputStream ostream1, ostream2;
    /** sole TeeOutputStream constructor */
    public TeeOutputStream(OutputStream o1, OutputStream o2) throws IOException {
        ostream1 = o1;
        ostream2 = o2;
    public void close() throws IOException {
        ostream1.close();
        ostream2.close();
    public void flush() throws IOException {
        ostream1.flush();
        ostream2.flush();
    public void write(int b) throws IOException {
        byte[] buf = new byte[1];
        buf[0] = (byte)b;
        write(buf, 0, 1);
    public void write(byte[] b, int off, int len) throws IOException {
        ostream1.write(b, off, len);
        ostream2.write(b, off, len);
    /** test class */
    static class Test {
        public static void main (String args[]) {
            final String f1 = "tee1.out", f2 = "tee2.out";
            int ch;
            try {
                // create a TeeOutputStream with System.out and a file
                // as output streams
                TeeOutputStream t1 = new TeeOutputStream(
                    System.out, new FileOutputStream(f1));
                // create a TeeOutputStream with t1 and a second file as
                // output streams
                TeeOutputStream tee = new TeeOutputStream(
                    t1,    new FileOutputStream(f2));
                // read characters from System.in and write to the tee
                while ((ch = System.in.read()) != -1) {
                    tee.write(ch);
                tee.close(); // close the tee
            } catch(FileNotFoundException e) {
                System.err.println(e.getMessage());
            } catch(IOException e) {
                System.err.println(e.getMessage());
}