Servlet cannot receive message from applet after sent message to applet

Question

In my Applet-Servlet communication, my servlet can not receive message from the applet after the servlet sent message to the applet. It will throw java.io.EOFException: Expecting code
Can someone tell me what is wrong?
==============
This is relevant code on applet side:
String inMsg = "";
try {
_owner.textArea.append("run start...please wait......\n");
String location = "http://111.111.11.111:8080/mdo/servlet/BLServlet";
URL servletURL = new URL(location);
URLConnection servletConnection = servletURL.openConnection();
     _owner.textArea.append("URL = "+location+"\n");
servletConnection.setDoOutput(true);
servletConnection.setDoInput(true);
servletConnection.setUseCaches(false);
servletConnection.setDefaultUseCaches(false);
servletConnection.setRequestProperty("Content-Type", "application/octet-stream");
_owner.textArea.append("servlet connection: \n  "+servletConnection.toString()+"\n");
outputToServlet = new ObjectOutputStream(servletConnection.getOutputStream());
_owner.textArea.append("output to servelt:  "+outputToServlet.toString()+"\n");
_owner.textArea.append("Send msg: Register\n");
outputToServlet.writeObject("Register");
_owner.textArea.append("Sent. \n");
outputToServlet.flush();
_owner.textArea.append("Flush. \n");
try {
Thread.sleep(3000);
} catch (InterruptedException exc) {
_owner.textArea.append("Cannot Sleep.\n");
return;
inputFromServlet = new ObjectInputStream(servletConnection.getInputStream());
_owner.textArea.append("input from servlet:   "+inputFromServlet.toString()+"\n");
Object inMessage = new Object();
inMessage = (Object) inputFromServlet.readObject();
inMsg = inMessage.toString();
_owner.textArea.append("Receive: "+inMsg+"\n");
_owner.textArea.append("output-to-servelt:  "+outputToServlet.toString()+"\n");
_owner.textArea.append("input-from-servlet: "+inputFromServlet.toString()+"\n");
_owner.textArea.append("Send msg: Hello\n");
outputToServlet.writeObject("Hello");
_owner.textArea.append("Sent. \n");
outputToServlet.flush();
_owner.textArea.append("Flush. \n");
try {
Thread.sleep(3000);
} catch (InterruptedException exc) {
_owner.textArea.append("Cannot Sleep.\n");
return;
_owner.textArea.append("output-to-servelt:  "+outputToServlet.toString()+"\n");
_owner.textArea.append("input-from-servlet: "+inputFromServlet.toString()+"\n");
inMessage = new Object();
inMessage = (Object) inputFromServlet.readObject();
inMsg = inMessage.toString();
_owner.textArea.append("Receive: "+inMsg+"\n");
_owner.textArea.append("End of run\n");
} catch (Exception e) {
_owner.textArea.append("Exception:  "+e.toString()+"\n");
Code on Servlet side:
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String inMsg;
try {
textArea.append("start of main\n");
inputFromApplet = new ObjectInputStream(request.getInputStream());
inMsg = (String) inputFromApplet.readObject();
textArea.append(" - BLServlet - from Applet: "+inMsg+"\n");
if (inMsg.equals("Register")) {
outMsg = "Register Accept";
} else {
outMsg = "MISTAKE2";
textArea.append("output message: "+outMsg+"\n");
outputToApplet = new ObjectOutputStream(response.getOutputStream());
textArea.append("object output stream: "+outputToApplet.toString()+"\n");
outputToApplet.writeObject(outMsg);
outputToApplet.flush();
try {
Thread.sleep(3000);
} catch (InterruptedException exc) {
return;
inMsg = (String) inputFromApplet.readObject();//Throw java.io.EOFException: Expecting code
textArea.append(" - BLServlet - from Applet: "+inMsg+"\n");
inputFromApplet.close();
if (inMsg.equals("Hello")) {
outMsg = "Hello! How are you!";
else {
outMsg = "MISTAKE3";
textArea.append("output message: "+outMsg+"\n");
outputToApplet.writeObject(outMsg);
outputToApplet.flush();
} catch (Exception exc) {
textArea.append("Exception: "+exc.toString()+"\n");
return;
} // end of try/catch
} // end of doPost method

Answer 1

I have the same problem. I'm trying to send an ImageIcon through an ObjectOutputStream from an Applet to a Servlet. Here is my code:
URL url = new URL(getCodeBase(),"/License/SnapshotServlet");
URLConnection con = url.openConnection();
con.setDoOutput(true);
con.setUseCaches(false);
con.setRequestProperty("Content-Type", "application/x-java-serialized-object");
OutputStream os = con.getOutputStream();
BufferedOutputStream bos = new BufferedOutputStream(os);
ObjectOutputStream oos = new ObjectOutputStream(bos);
oos.writeObject(icon);
oos.flush();
oos.close();
Here is my error:
[5/6/02 17:41:31:312 CDT] 7f8b8205 SystemOut     U service() called
java.io.EOFException
at java.io.DataInputStream.readFully(DataInputStream.java:168)
at java.io.ObjectInputStream.readFully(ObjectInputStream.java:2076)
at java.io.ObjectInputStream.inputArray(ObjectInputStream.java:1085)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:380)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:242)
at javax.swing.ImageIcon.readObject(ImageIcon.java:373)
at java.lang.reflect.Method.invoke(Native Method)
at java.io.ObjectInputStream.invokeObjectReader(ObjectInputStream.java:2219)
at java.io.ObjectInputStream.inputObject(ObjectInputStream.java:1416)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:392)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:242)
at dps.license.webcam.SnapshotServlet.doPost(SnapshotServlet.java:39)
at dps.license.webcam.SnapshotServlet.service(SnapshotServlet.java:75)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at com.ibm.servlet.engine.webapp.StrictServletInstance.doService(ServletManager.java:827)
at com.ibm.servlet.engine.webapp.StrictLifecycleServlet._service(StrictLifecycleServlet.java:167)
at com.ibm.servlet.engine.webapp.IdleServletState.service(StrictLifecycleServlet.java:297)
at com.ibm.servlet.engine.webapp.StrictLifecycleServlet.service(StrictLifecycleServlet.java:110)
at com.ibm.servlet.engine.webapp.ServletInstance.service(ServletManager.java:472)
at com.ibm.servlet.engine.webapp.ValidServletReferenceState.dispatch(ServletManager.java:1012)
at com.ibm.servlet.engine.webapp.ServletInstanceReference.dispatch(ServletManager.java:913)
at com.ibm.servlet.engine.webapp.WebAppRequestDispatcher.handleWebAppDispatch(WebAppRequestDispatcher.java:523)
at com.ibm.servlet.engine.webapp.WebAppRequestDispatcher.dispatch(WebAppRequestDispatcher.java:282)
at com.ibm.servlet.engine.webapp.WebAppRequestDispatcher.forward(WebAppRequestDispatcher.java:112)
at com.ibm.servlet.engine.srt.WebAppInvoker.doForward(WebAppInvoker.java:91)
at com.ibm.servlet.engine.srt.WebAppInvoker.handleInvocationHook(WebAppInvoker.java:184)
at com.ibm.servlet.engine.invocation.CachedInvocation.handleInvocation(CachedInvocation.java:67)
at com.ibm.servlet.engine.invocation.CacheableInvocationContext.invoke(CacheableInvocationContext.java:106)
at com.ibm.servlet.engine.srp.ServletRequestProcessor.dispatchByURI(ServletRequestProcessor.java:125)
at com.ibm.servlet.engine.oselistener.OSEListenerDispatcher.service(OSEListener.java:315)
at com.ibm.servlet.engine.http11.HttpConnection.handleRequest(HttpConnection.java:60)[5/6/02 17:41:31:859 CDT] 7f8b8205 SystemOut     U saving image...
[5/6/02 17:41:31:859 CDT] 7f8b8205 SystemOut     U ERROR: Image is null!
at com.ibm.ws.http.HttpConnection.readAndHandleRequest(HttpConnection.java:323)
at com.ibm.ws.http.HttpConnection.run(HttpConnection.java:252)
at com.ibm.ws.util.CachedThread.run(ThreadPool.java:122)
Does anyone have any idea what is going on here?