Internet TCPとUDPプロトコル
5477 ワード
一.概念
:
：HTTP/WebSocket(Html)、DNS、FTP、SMTP/POP3/IMAP、XMPP/MQTT、TELNET/SSH
：TCP/UDP(Socket)、DCCP、RTP、PPTP
：IP、ICMP(ping)、IGMP、RIP
: IP
: bit , ,
MTU( )：
FDDI ：4352
Ethernet ：1500
PPPoE(ADSL) ：1492
X.25 (Dial Up/Modem)：576
Point-to-Point：4470
MTU, IP ,IP ！
TCP , 576 , IP ！
( ),UDP 1472 ！
, , MTU 576 ,UDP 576 ！
TCP : , , , ;
,
java : Socket/ServerSocket
UDP : , , ;
,
,
java : DatagramSocket/DatagramPacket
HTTP :
HTTP TCP , ,
: , ( ) ,
, ！
, , , ！
HTTP1.1 ( TCP ), , !
HTTP TCP , ！
: , , !
，Html5 WebSocket Http ！
TCP , , ip , ( )
// TCP
public class TCPClient{
public static void main(String args[]) throws Exception{
// 1. IP ，
String ip = args[0];
int port = Integer.parseInt(args[1]);
String filePath = args[2];
Socket socket = new Socket(ip, port);
// 2. TCP ，
new DataOutputStream(socket.getOutputStream()).writeUTF(filePath);
// 3. ， ，
DataInputStream sin = new DataInputStream(socket.getInputStream());
FileOutputStream fou = new FileOutputStream(System.currentTimeMillis()+"_"+sin.readUTF());
long len = sin.readLong();
int pro=0;
int l;
byte[] b = new byte[1024*1024];
while ((l = sin.read(b)) != -1) {
fou.write(b,0,l);
pro += l;
System.out.println(" "+String.format("%.2f",pro/1024f/1024)+"MB, "+
" "+String.format("%.2f",pro*100f/len)+"%");
}
sin.close();
fou.close();
socket.close();
}
}
// TCP
public class TCPServer{
public static void main(String arg[]) throws Exception{
// 1.
String port = arg[0];
ServerSocket serverSocket = new ServerSocket(Integer.parseInt(port));
while (true) {
// 2. ,
System.out.println(" "+port+" 。。。
");
Socket socket = serverSocket.accept();
// 3.TCP ，
String filePath = new DataInputStream(socket.getInputStream()).readUTF();
File file = new File(filePath);
FileInputStream fin = new FileInputStream(file);
System.out.println("TCP ， "+filePath);
// 4.
DataOutputStream sou = new DataOutputStream(socket.getOutputStream());
sou.writeUTF(file.getName());
sou.writeLong(file.length());
byte[] b = new byte[1024*1024];
int l;
while ((l = fin.read(b)) != -1) {
sou.write(b, 0, l);
System.out.println(" 。。。");
}
System.out.println("
");
fin.close();
sou.close();
socket.close();
}
}
}
// UDP
public class UDPClient{
public static void main(String[] args)throws IOException{
// 1. ( )
DatagramSocket dsocket = new DatagramSocket();
byte[] sen = " ! UDP ".getBytes("utf-8");
dsocket.send(new DatagramPacket(sen,sen.length,InetAddress.getByName("localhost"),9999));
System.out.println(" ");
// 2.
DatagramPacket rec = new DatagramPacket(new byte[100],100);
dsocket.receive(rec);
dsocket.close();
System.out.println(" :" + new String(rec.getData(),0,rec.getLength()));
}
}
// UDP
public class UDPServer{
public static void main(String[] args)throws IOException{
DatagramSocket dsocket = new DatagramSocket(9999);
DatagramPacket rec = new DatagramPacket(new byte[100], 100);
while (true) {
// 1.
System.out.println(" ...");
dsocket.receive(rec); // ,
// 2.
System.out.println(" :"+new String(rec.getData(), 0, rec.getLength()));
// 3.
byte[] sec = " ! ".getBytes("utf-8");
dsocket.send(new DatagramPacket(sec, sec.length, rec.getAddress(), rec.getPort()));
System.out.println(" !");
}
}