mk.persia
Reputation: 49
java socket programming problem
what's wrong with my code? sorry about my bad English
package sockettest;
import java.io.*;
import java.net.*;
class sevr implements Runnable{
public void run() {
ServerSocket sSkt = null;
Socket skt = null;
BufferedReader br = null;
BufferedWriter bw = null;
try{
System.out.println("Server: is about to create socket");
sSkt = new ServerSocket(6666);
System.out.println("Server: socket created");
}
catch(IOException e){
System.out.println("Server: socket creation failure");
}
try{
System.out.println("Server: is listening");
skt = sSkt.accept();
System.out.println("Server: Connection Established");
}
catch(IOException e){
System.out.println("Server: listening failed");
}
try{
System.out.println("Server: creating streams");
br = new BufferedReader(new InputStreamReader(skt.getInputStream()));
bw = new BufferedWriter(new OutputStreamWriter(skt.getOutputStream()));
System.out.println("Server: stream done");
}
catch(IOException e){
System.out.println("Server: stream failed");
}
System.out.println("Server: reading the request");
try{
String line = null;
while((line =br.readLine()) != null){
System.out.println("Server: client said-> "+ line);
}
}
catch(IOException e){
System.out.println("Server: reading failed");
}
System.out.println("Server: reading fished");
System.out.println("Server: responding");
try{
bw.write("Hi! I am server!");
}
catch(IOException e){
System.out.println("Server: responding failed");
}
System.out.println("Server: responding finished");
System.out.println("Server: is finishing");
try {
br.close();
bw.close();
skt.close();
sSkt.close();
} catch (IOException e) {
System.out.println("Server: finishing failed");
}
System.out.println("Server: done");
}
}
class clnt implements Runnable{
public void run() {
Socket skt = null;
BufferedReader br = null;
BufferedWriter bw = null;
try{
System.out.println("Client: about to create socket");
skt = new Socket(InetAddress.getLocalHost(),6666);
System.out.println("Client: socket created");
}
catch(IOException e){
System.out.println("Client: socket creation failure");
}
try{
System.out.println("Client: creating streams");
br = new BufferedReader(new InputStreamReader(skt.getInputStream()));
bw = new BufferedWriter(new OutputStreamWriter(skt.getOutputStream()));
System.out.println("Client: stream done");
}
catch(IOException e){
System.out.println("Client: stream failed");
}
System.out.println("Client: requesting");
try{
bw.write("Hi! I am Client!");
}
catch(IOException e){
System.out.println("Client: requesting failed");
}
System.out.println("Client: requesting finished");
System.out.println("Client: reading the respond");
try{
String line = null;
while((line =br.readLine()) != null){
System.out.println("Client: server said-> "+ line);
}
}
catch(IOException e){
System.out.println("Client: reading failed");
}
System.out.println("Client: reading fished");
System.out.println("Clientrver: is finishing");
try {
br.close();
bw.close();
skt.close();
} catch (IOException e) {
System.out.println("Client: finishing failed");
}
System.out.println("Client: done");
}
}
public class Main {
public static void main(String[] args) {
System.out.println("Main started");
Thread sThread = new Thread(new sevr());
Thread cThread = new Thread(new clnt());
sThread.start();
cThread.start();
try {
sThread.join();
cThread.join();
} catch (InterruptedException ex) {
System.out.println("joining failed");
}
System.out.println("Main done");
}
}
output:
Main started Server: is about to create socket Client: about to create socket Client: socket created Client: creating streams Server: socket created Server: is listening Server: Connection Established Server: creating streams Server: stream done Server: reading the request Client: stream done Client: requesting Client: requesting finished Client: reading the respond
and it waits here forever!
Upvotes: 1
Views: 1529
Answers (3)
Peter Lawrey
Reputation: 533510
The program is using a BufferedWriter but this is not flushed (it will sit in the buffer until it is flushed, the buffer fills or closed) and there is no newline sent (the readLine will wait until you send a newline)
try
bw.write("I am the Client!!\n");
bw.flush();
Upvotes: 3
mk.persia
Reputation: 49
now it works
package sockettest;
import java.io.*;
import java.net.*;
class sevr implements Runnable{
public void run() {
ServerSocket sSkt = null;
Socket skt = null;
BufferedReader br = null;
BufferedWriter bw = null;
try{
System.out.println("Server: is about to create socket");
sSkt = new ServerSocket(6666);
System.out.println("Server: socket created");
}
catch(IOException e){
System.out.println("Server: socket creation failure");
}
try{
System.out.println("Server: is listening");
skt = sSkt.accept();
System.out.println("Server: Connection Established");
}
catch(IOException e){
System.out.println("Server: listening failed");
}
try{
System.out.println("Server: creating streams");
br = new BufferedReader(new InputStreamReader(skt.getInputStream()));
bw = new BufferedWriter(new OutputStreamWriter(skt.getOutputStream()));
System.out.println("Server: stream done");
}
catch(IOException e){
System.out.println("Server: stream failed");
}
System.out.println("Server: reading the request");
try{
String line = null;
line = br.readLine();
System.out.println("Server: client said-> "+ line);
}
catch(IOException e){
System.out.println("Server: reading failed");
}
System.out.println("Server: reading fished");
System.out.println("Server: responding");
try{
bw.write("Hi! I am server!\n");
bw.flush();
}
catch(IOException e){
System.out.println("Server: responding failed");
}
System.out.println("Server: responding finished");
System.out.println("Server: is finishing");
try {
br.close();
bw.close();
skt.close();
sSkt.close();
} catch (IOException e) {
System.out.println("Server: finishing failed");
}
System.out.println("Server: done");
}
}
class clnt implements Runnable{
public void run() {
Socket skt = null;
BufferedReader br = null;
BufferedWriter bw = null;
try{
System.out.println("Client: about to create socket");
skt = new Socket(InetAddress.getLocalHost(),6666);
System.out.println("Client: socket created");
}
catch(IOException e){
System.out.println("Client: socket creation failure");
}
try{
System.out.println("Client: creating streams");
br = new BufferedReader(new InputStreamReader(skt.getInputStream()));
bw = new BufferedWriter(new OutputStreamWriter(skt.getOutputStream()));
System.out.println("Client: stream done");
}
catch(IOException e){
System.out.println("Client: stream failed");
}
System.out.println("Client: requesting");
try{
bw.write("Hi! I am Client!\n");
bw.flush();
}
catch(IOException e){
System.out.println("Client: requesting failed");
}
System.out.println("Client: requesting finished");
System.out.println("Client: reading the respond");
try{
String line = null;
line =br.readLine();
System.out.println("Client: server said-> "+ line);
}
catch(IOException e){
System.out.println("Client: reading failed");
}
System.out.println("Client: reading fished");
System.out.println("Client: is finishing");
try {
br.close();
bw.close();
skt.close();
} catch (IOException e) {
System.out.println("Client: finishing failed");
}
System.out.println("Client: done");
}
}
public class Main {
public static void main(String[] args) {
System.out.println("Main started");
Thread sThread = new Thread(new sevr());
Thread cThread = new Thread(new clnt());
sThread.start();
cThread.start();
try {
sThread.join();
cThread.join();
} catch (InterruptedException ex) {
System.out.println("joining failed");
}
System.out.println("Main done");
}
}
output:
Main started
Server: is about to create socket
Client: about to create socket
Client: socket created
Client: creating streams
Server: socket created
Server: is listening
Server: Connection Established
Server: creating streams
Client: stream done
Server: stream done
Server: reading the request
Client: requesting
Client: requesting finished
Client: reading the respond
Server: client said-> Hi! I am Client!
Server: reading fished
Server: responding
Server: responding finished
Server: is finishing
Client: server said-> Hi! I am server!
Client: reading fished
Client: is finishing
Client: done
Server: done
Main done
Upvotes: -1
