Aide à comprendre Classe Java
salut
je suis débutant en langage Java et je suis entrain d'apprendre de jour en jour a programmer cependant sur mes recherches j'ai trouvé une Classe java sur Web que je n'arrive pas a comprendre , il ne s' agit pas de copier coller mais je veut juste comprendre cette Classe
il s'agit de la Classe suivante Chat Server programmer pour creer un serveur d'une application :
je veut juste comprendre comment elle marche ?
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| import java.net.*;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class ChatServer {
DatagramSocket ds;
byte[] recbuf = new byte[1024];
DatagramPacket rec = new DatagramPacket(recbuf, recbuf.length);
int port;
String newAddress = "";
String addressList = "";
String sendAddressList = "";
public ChatServer(int port) {
this.port = port;
}
public void init() throws Exception {//DatagramSocket
if (port < 1024 || port > 65535) {
System.out.println("initialisation du port a la valeur 2008 ");
ds = new DatagramSocket(2008);
} else {
ds = new DatagramSocket(port);
}
}
public void start() throws Exception {
println("demarrage du port");
println("valeur du port" + port);
init();
receive();
}
public void receive() {
for ( ; ; ) {
try {
ds.receive(rec);
String msg = new String(rec.getData(), rec.getOffset(), rec.getLength());
String natAddress = rec.getAddress().toString().substring(1);
int natPort = rec.getPort();
String Num = msg.substring(0,1);
msg = msg.substring(2);
String line;
switch(Integer.parseInt(Num)){//
case 1 : {
line = "Ò»¸öеÄÓû§µÇ¼: " + msg + " NATµØÖ·: " + natAddress + " ¹ÜÀí¶Ë¿Ú: " + natPort;
sendAddressList = sendAddressList + natAddress + " " + natPort + " ";
newAddress = msg + ":" + natAddress + ":" + natPort;
println(line);
break;
}
case 2 : {
line = "ÒôƵ¶Ë¿Ú: " + natPort;
newAddress = newAddress + ":" + natPort;
println(line);
break;
}
case 3 : {
line = "ÒôƵRTCP¶Ë¿Ú: " + natPort;
newAddress = newAddress + ":" + natPort;
println(line);
break;
}
case 4 : {
line = "ÊÓƵ¶Ë¿Ú: " + natPort;
newAddress = newAddress + ":" + natPort;
println(line);
break;
}
case 5 : {
line = "ÊÓƵRTCP¶Ë¿Ú: " + natPort;
newAddress = newAddress + ":" + natPort;
println(line);
if (!sendAddressList.equals(""))
doSend("1 " + newAddress, sendAddressList);
if(!addressList.equals("")){
String address[] = newAddress.split(":");
doSend("7 " + addressList,
address[1] + " " + address[2]);
}
addressList = addressList + newAddress + " ";
break;
}
case 6 : {
line = "Ò»¸ö¿Í»§À뿪: " + msg + " NATµØÖ·: " + natAddress + " ¹ÜÀí¶Ë¿Ú: " + natPort;
println(line);
delAddress(msg, natAddress, natPort);
if(!sendAddressList.equals(""))
doSend("6 " + msg + ":" + natAddress, sendAddressList);
break;
}
case 7 : break;
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
public void doSend(String msgSend, String sendAddressList) throws Exception {
String[] s = sendAddressList.split(" ");
byte[] data = msgSend.getBytes();
for(int i =0; i < s.length; i++){
DatagramPacket pack = new DatagramPacket(data, data.length, InetAddress.getByName(s[i]), Integer.parseInt(s[++i]));
ds.send(pack);
}
}
public void delAddress(String msg, String natAddress, int ctrlPort){
String regEx = msg + ":" + natAddress + ":" + ctrlPort + ":.{1,5}:.{1,5}:.{1,5}:.{1,5} ";
Pattern p = Pattern.compile(regEx);
Matcher m=p.matcher(addressList);
String s = m.replaceAll("");
addressList = s;
regEx = natAddress + " " + ctrlPort + " ";
p = Pattern.compile(regEx);
m = p.matcher(sendAddressList);
s = m.replaceAll("");
sendAddressList = s;
}
public void println(String s) {
Date nowTime = new Date();
SimpleDateFormat fmt = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss aa", Locale.US);
System.out.println(fmt.format(nowTime) + "----" + s);
}
public static void main(String[] args) throws Exception {
new ChatServer(2008).start();
}
} |
