Parse method of JAXP DocumentBuilder using InputStream

Question

I am having some problem. I am working on a generic XML messaging client server pair. The crux of it is that I am using the Transformer object to send data from the client to the server, using a Socket InputStream. The I do exactly the same from the server side to the client side.
Example (client side):
OutputStream out = socket.getOutputStream();
Transformer transformer =
TransformerFactory.newInstance().newTransformer();
transformer.transform(new DOMSource(request),
new StreamResult(out));
Example (server side, in the thread for the connection):
InputStream in = socket.getInputStream();
DocumentBuilder builder =
DocumentBuilderFactory.newInstance
().newDocumentBuilder();
Document request = builder.parse(in);
The problem I am experiencing is that the parse method on the server side is never completing. The parse method does not return at all. I can understand that this is due to the InputStream still being open, and need to know how can I let the parse method know that I am done writing to the OutputStream at the client side. Should I be sending an EOF character of sorts? If I should, what byte value represents this, and what do I need to do?
Thank you
Heinrich Pool

Answer 1

Sorry hadn't noticed the Code Tags before. So the code formatted
package de.gaskin.xml;
import de.gaskin.buf.Buffer;
import de.gaskin.io.LineArray;
import de.gaskin.util.Debug;
import java.net.Socket;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.ByteArrayOutputStream;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.util.Vector;
import org.w3c.dom.Document;
A Simple to use generic XML Document transfer based on sockets.
<H2>Theory of Operation.</h2>
<p>A client sends an array of lines (an XML document) prepended by a line
that ONLY contains an integer (the number of lines in the document that
follows).
<p>The server reads the first line (so that it knows how many lines belong to
the next document) it then reads the specified number of lines into memory and
when all lines have been read in passes them (as an InputStream) to an
XMLParser to produce an XML DOM that is made available through the<br>
<code>getDocument()</code> method.
<h2>API</h2>
The API is very simple to use as the following templates demonstrate.
<h3>Client</h3>
<pre>
    public class MyXmlSocketClient extends XmlSocket {
       MyXmlSocketClient(String serverAddress, String fileName) {
          super(serverAddress, 4711);
          run(fileName);
</pre>
<h3>Server Worker</h3>
    <pre>
    public class MyXmlSocketServer extends XmlSocket {
       MyXmlSocketServer(Socket s) {
          super(s);
       public void run() {
          Document doc = getDocument();
          // Process document
    </pre>
<h3>Server Listener</h3>
    <pre>
    public class MyXmlServer {
       ServerSocket ss;
       boolean      stop;
       MyXmlSocketServer() {
          stop = false;
          try {
             ss = new ServerSocket(4711);
             while (! stop) {
                Socket s = ss.accept();
                new Thread(new MyXmlServerSocket(s));
          catch (Exception x) {
             x.printStackTrace();
    </pre>
<P>Last updated 10th Jan 2001.
@author  David. M. Gaskin.
@version Version 1.0 Oct 2000
@since    Version 1.0
public class XmlSocket implements Runnable {
   final static boolean debug = false;
   protected BufferedReader  data;
  /* protected */ public PrintWriter     pw;
             Socket          socket;
   public XmlSocket(String domain, int port) {
      try {
         socket = new Socket(domain, port);
         common(socket);
      catch (Exception x) {
//       x.printStackTrace();
         throw new Error(x.toString());
   public XmlSocket(Socket s) {
      socket = s;
      common(s);
   void common(Socket s) {
      try {
         data = new BufferedReader(new InputStreamReader(s.getInputStream()));
         pw   = new PrintWriter(s.getOutputStream(), true);
      catch (Exception x) {
//       x.printStackTrace();
         throw new Error(x.toString());
   public Document getDocument() {
      Document rc = null;
      try {
         String line = data.readLine();
         int    linesInDoc = Integer.parseInt(line.trim());
         if (linesInDoc != -1) {
            ByteArrayOutputStream os = new ByteArrayOutputStream();
            for (int i = 0;i < linesInDoc;i++) {
               line = data.readLine();
               System.out.println(line);
               byte[] byteLine = line.getBytes();
               os.write(byteLine, 0, byteLine.length);
//          System.out.println("END");
            rc = XmlFactory.readIn(new ByteArrayInputStream(os.toByteArray()));
      catch (Exception x) {
         x.printStackTrace();
      return rc;
   public void run(Vector lines) {
      int loopCnt = lines.size();
      if (debug) {
         println("" + loopCnt);
         for (int i = 0;i < loopCnt;i++) {
            println((String)lines.elementAt(i));
//       pw.flush();
         println("-1");
      else {
         pw.println("" + loopCnt);
         for (int i = 0;i < loopCnt;i++) {
            pw.println((String)lines.elementAt(i));
//       pw.flush();
         pw.println("-1");
      pw.flush();
   void println(String s) {
      System.out.println(s);
      pw.println(s);
   public void run() {
      Debug.d(this, "run", "S H O U L D   N E V E R   B E   I N V O K E D");
   public void run(String filename) {
      Buffer[] input = LineArray.readIn(filename);
      send(input);
   public void run(File file) {
      Buffer[] input = LineArray.readIn(file.getAbsolutePath());
      send(input);
   void send(Buffer[] input) {
      int loopCnt = input.length;
      pw.println("" + loopCnt);
      for (int i = 0;i < loopCnt;i++) {
         pw.println(input.toString());
pw.flush();
pw.println("-1");
pw.flush();
public int getDocIdx(String[] roots, Document doc) {
int rc = -1;
String rootName = doc.getDocumentElement().getTagName();
int loopCnt = roots.length;
for (int i = 0;i < loopCnt;i++) {
if (rootName.equals(roots[i])) {
rc = i;
break;
if (rc < 0)
System.out.println(rootName + " N O T F O U N D");
return rc;
public Socket getSocket() {
return socket;
For testing only
public static void main(String[] args) {
XmlSocket xmlS = new XmlSocket("localhost", 36);
xmlS.getDocument();