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Question

This is reference to an earlier post :-
http://forum.java.sun.com/thread.jsp?forum=54&thread=344129&tstart=0&trange=15
The idea behind the program as a whole is to create a client sever type of program that allows the client to send messages to a server and then retrieve a reply from the server. I have got that sussed out. But i want to make the program so it can connect to a server at different addresses. At the moment in the code it can only search for the server at the loop back address, or local server.
cpSocket = new Socket("localhost", 9111);
what i want to do is make the "localhost" a variable so when the program starts it will ask the user for a ip address, and then fill in the value of the variable instead of the "localhost".
I thought that this would work but it doesn't compile
public static void main(String[] args) throws IOException {
Socket cpSocket = null;
PrintWriter out = null;
BufferedReader in = null;
try{
BufferedReader ha = new BufferedReader(
new InputStreamReader(System.in));
String input = ha.readLine();
System.out.println(" Host Address :" + ha);
}catch(IOException e){
System.out.println(e);
try {
cpSocket = new Socket(ha, 9111);
out = new PrintWriter(cpSocket.getOutputStream(), true);
in = new BufferedReader(new InputStreamReader(cpSocket.getInputStream()));
} catch (UnknownHostException e) {
System.err.println("Don't know about host: localhost.");
System.exit(1);
} catch (IOException e) {
System.err.println("Couldn't get I/O for the connection to: localhost.");
System.exit(1);
It gives an error related to the ha variable in the cpSocket line of code.
Can you help?
Thankyou

Answer 1

>
public static void main(String[] args) throws
ows IOException {
Socket cpSocket = null;
PrintWriter out = null;
BufferedReader in = null;
try{
BufferedReader ha = new BufferedReader(
new InputStreamReader(System.in));
String input = ha.readLine();--> that's the variable containing some value like "localhost"
System.out.println(" Host Address :" + ha);--> so here you should write the following:
System.out.println(" Host Address :" + input);
>
}catch(IOException e){
System.out.println(e);
try {
cpSocket = new Socket(ha, 9111);--> same here, try:
cpSocket = new Socket(input, 9111);
But i think, you will get a compiler error like "Variable "input" may not have been initialized" That is because you have declared and used the variable in two different try blocks. So just use one big try block.
public static void main(String[] args)
throws IOException
Socket cpSocket = null;
PrintWriter out = null;
BufferedReader in = null;
try
BufferedReader ha = new BufferedReader(
new InputStreamReader(System.in));
String input = ha.readLine();
System.out.println(" Host Address :" + input);
cpSocket = new Socket(input, 9111);
out = new PrintWriter(cpSocket.getOutputStream(), , true);
in = new BufferedReader(new dReader
(new InputStreamReader(cpSocket.getInputStream()));
catch (UnknownHostException e)
System.err.println("Don't know about host: " + input);
System.exit(1);
catch (IOException e)
System.err.println("Couldn't get I/O for the connection to:" + input);
System.exit(1);
}