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Commit d88322ee authored by Brutzman, Don's avatar Brutzman, Don
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explicitly catch InterruptedException, rename variable for clarity

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examples/src/TcpExamples/Assignment1TCPExample3ClientChange.java
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package TcpExamples;
import java.io.*;
import java.net.*;
/**
* This is Assignment 1 where I have modified the given code from TCPExample3Client
* -sleep time has been extended to give more time in between loops
* -Initial print line has been altered to reflect assingnment 1
* -Loop only runs a finite number of times ,10.
* Before, we always used telnet (netcat) to connect to the server. Here we are
* now writing our own program to do the connection.
*
* As you will see, when we run this after we start the server we will see the
* same string telnet printed, sent by the server. The output at the server will
* show different socket pairs for each time the loop iterates.
*
* @author mcgredo
* @author brutzman
*/
public class Assignment1TCPExample3ClientChange {
/** IPv6 String constant for localhost address, similarly IPv4 127.0.0.1
* @see <a href="https://en.wikipedia.org/wiki/localhost">https://en.wikipedia.org/wiki/localhost</a>
* @see <a href="https://en.wikipedia.org/wiki/IPv6_address">https://en.wikipedia.org/wiki/IPv6_address</a>
*/
public final static String LOCALHOST = "0:0:0:0:0:0:0:1";
/**
* Program invocation, execution starts here
* @param args command-line arguments
*/
public static void main(String[] args) throws InterruptedException {
// Local variables/fields
Socket socket = null;
InputStream is;
Reader isr;
BufferedReader br;
String serverMessage;
int clientLoopCount = 0;
int numbLoops = 10;
try {
while (clientLoopCount < numbLoops)
{
clientLoopCount++; // increment at beginning of loop for reliability
System.out.println(Assignment1TCPExample3ClientChange.class.getName() + " creating socket...");
// We request an IP to connect to ("localhost") and
// port number at that IP (2317). This establishes
// a connection to that IP in the form of a Socket
// object; the server uses a ServerSocket to wait for
// connections.
socket = new Socket(LOCALHOST, 2317); // locohost?
// Now hook everything up (i.e. set up the streams), Java style:
is = socket.getInputStream();
isr = new InputStreamReader(is);
br = new BufferedReader(isr);
// Read a single line written by the server. We'd
// do things a bit differently if there were many lines to be read
// from the server instead of one only.
serverMessage = br.readLine();
System.out.println("======================Assignment1===========================");
System.out.print ("Client loop " + clientLoopCount + ": ");
System.out.println("now we're talking!");
System.out.println("The message the server sent was: '" + serverMessage + "'");
// socket gets closed, either automatically/silently by this code (or possibly by the server)
Thread.sleep(800l); // slow things down, for example 500l (long) = 500 msec
} // end while(true) // infinite loops are dangerous, be sure to kill this process!
}
catch (IOException e)
{
System.err.println("Problem with " + TcpExample3Client.class.getName() + " networking:"); // describe what is happening
System.err.println("Error: " + e);
// Provide more helpful information to user if exception occurs due to running twice at one time
if (e instanceof java.net.BindException) {
System.err.println("*** Be sure to stop any other running instances of programs using this port!");
}
}
finally // occurs after any other activity when shutting down
{
try {
if (socket != null)
socket.close();
} catch (IOException e) {}
// program exit: tell somebody about that happening. Likely cause: server drops connection.
System.out.println();
System.out.println(TcpExample3Client.class.getName() + " exit");
}
}
}
package TcpExamples;
import java.io.*;
import java.net.*;
/**
* This is Assignment 1 where I have modified the given code from TCPExample3Client
* -sleep time has been extended to give more time in between loops
* -Initial print line has been altered to reflect assingnment 1
* -Loop only runs a finite number of times ,10.
* Before, we always used telnet (netcat) to connect to the server. Here we are
* now writing our own program to do the connection.
*
* As you will see, when we run this after we start the server we will see the
* same string telnet printed, sent by the server. The output at the server will
* show different socket pairs for each time the loop iterates.
*
* @author mcgredo
* @author brutzman
*/
public class Assignment1TCPExample3ClientChange {
/** IPv6 String constant for localhost address, similarly IPv4 127.0.0.1
* @see <a href="https://en.wikipedia.org/wiki/localhost">https://en.wikipedia.org/wiki/localhost</a>
* @see <a href="https://en.wikipedia.org/wiki/IPv6_address">https://en.wikipedia.org/wiki/IPv6_address</a>
*/
public final static String LOCALHOST = "0:0:0:0:0:0:0:1";
/**
* Program invocation, execution starts here
* @param args command-line arguments
*/
public static void main(String[] args)
{
// Local variables/fields
Socket socket = null;
InputStream is;
Reader isr;
BufferedReader br;
String serverMessage;
int clientLoopCount = 0;
int numberOfLoops = 10;
try {
while (clientLoopCount < numberOfLoops)
{
clientLoopCount++; // increment at beginning of loop for reliability
System.out.println(Assignment1TCPExample3ClientChange.class.getName() + " creating socket...");
// We request an IP to connect to ("localhost") and
// port number at that IP (2317). This establishes
// a connection to that IP in the form of a Socket
// object; the server uses a ServerSocket to wait for
// connections.
socket = new Socket(LOCALHOST, 2317); // locohost?
// Now hook everything up (i.e. set up the streams), Java style:
is = socket.getInputStream();
isr = new InputStreamReader(is);
br = new BufferedReader(isr);
// Read a single line written by the server. We'd
// do things a bit differently if there were many lines to be read
// from the server instead of one only.
serverMessage = br.readLine();
System.out.println("======================Assignment1===========================");
System.out.print ("Client loop " + clientLoopCount + ": ");
System.out.println("now we're talking!");
System.out.println("The message the server sent was: '" + serverMessage + "'");
// socket gets closed, either automatically/silently by this code (or possibly by the server)
Thread.sleep(800l); // slow things down, for example 500l (long) = 500 msec
} // end while(true) // infinite loops are dangerous, be sure to kill this process!
}
catch (IOException | InterruptedException e)
{
System.err.println("Problem with " + TcpExample3Client.class.getName() + " networking:"); // describe what is happening
System.err.println("Error: " + e);
// Provide more helpful information to user if exception occurs due to running twice at one time
if (e instanceof java.net.BindException) {
System.err.println("*** Be sure to stop any other running instances of programs using this port!");
}
}
finally // occurs after any other activity when shutting down
{
try {
if (socket != null)
socket.close();
} catch (IOException e) {}
// program exit: tell somebody about that happening. Likely cause: server drops connection.
System.out.println();
System.out.println(TcpExample3Client.class.getName() + " exit");
}
}
}
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