Socket Stream Communication Problem

Question

[My Server code]:
import java.io.*;
import java.net.*;
import java.util.*;
public class testserv {
public testserv() {
public static void main(String[] args) {
try {
ServerSocket ss = new ServerSocket(8999);
Socket so = ss.accept();
System.out.println("accept");
InputStream a = so.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(a));
System.out.println(br.readLine());
System.out.println(br.readLine());
ObjectInputStream ois = new ObjectInputStream(a);
String aa = (String)ois.readObject();
System.out.println(aa);
so.close();
} catch (Exception e) {e.printStackTrace();}
[My Client code]:
import java.io.*;
import java.net.*;
import java.util.*;
public class testcli {
public testcli() {
public static void main(String[] args) {
try {
Socket so = new Socket("140.114.79.236", 8999);
OutputStream out = so.getOutputStream();
PrintWriter pw = new PrintWriter(out, true);
pw.println("test");
pw.println("test2");
ObjectOutputStream oos = new ObjectOutputStream(out);
oos.writeObject(new String("test3"));
oos.flush();
so.close();
} catch (Exception e) {e.printStackTrace();}
When i use client connect to server, the output should be
accept
test
test2
test3
but the output is
accept
test
test2
java.io.EOFException
at java.io.ObjectInputStream$PeekInputStream.readFully(ObjectInputStream.java:2165)
at java.io.ObjectInputStream$BlockDataInputStream.readShort(ObjectInputStream.java:2634)
at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:734)
at java.io.ObjectInputStream.<init>(ObjectInputStream.java:253)
at core.test.testserv.main(testserv.java:20)
Is this stream's bug??
Or what mistake do i make??
Can somebody give me some advice??
Thank you in advance :)

Answer 1

you should have made a new thread of this.
Hello All,
Can anyone help?
I'm implementing a chat program with swing, sockets
and threads. I have got a basic version working
perfectly. I decided to upgrade it to include a
configuration (which is loaded and saved to file one
way or another). This configuration makes a record of
the users' favourite font.
i assume this part works. :)
In version.1 fonts were not implemented, so I was just
reading and writing (printing) from and to the
socket's I/O streams - no problem there.
In version.2 I have implemented a Message class, which
when sent contains the name of the sender (ie. what
the sender signed in as) the actually message as a
String, and a Font which is the font the sender uses.
I have tried to use the socket I/O streams :
1). to create Object I/O streams;
2). to create Bean XMLEncoders and XMLDecoders.
Neither of these two methods work and they are the
only way I can think of achieving what I want to do.
To be honest I don't know what happens - the JVM
doesn't throw an exception, just the instance acting
as the client hangs, while the instance acting as the
server ticks over as per usual. If I end the client
process (through task manager) an exception is thrown
in the server.it sounds like:
1. your server isn't very robust. :) any server operating in the real world should expect and deal with broken messages.
2. you need to read up on ObjectInputStreams and ObjectOutputStreams. if you want to go that route, they're what you need to look at.
personally, i'd recommend that you provide methods in the Message class to convert to and from a String, and send the Strings through a Writer attached to the socket. it's easier to recover from errors that way: you could throw a MessageFormatException or other such error without trashing your input stream. plus, it'd be easier to write non-java clients, in case you ever decide to go that route.