Socket TCP/UDP

TCP

TCPClient

 1 package com.tcp;
 2 
 3 import java.io.*;
 4 import java.net.*;
 5 
 6 class TCPClient 
 7 {
 8     public static void main(String argv[]) throws Exception
 9     {
10         String sentence;
11         String modifiedSentence;
12         BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));
13   
14         Socket clientSocket = new Socket("127.0.0.1", 6789);
15         DataOutputStream outToServer = 
　　　　　　　　new DataOutputStream(clientSocket.getOutputStream());
16         BufferedReader inFromServer = 
　　　　　　　　new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
17         sentence = inFromUser.readLine();
18         outToServer.writeBytes(sentence + '
');
19         modifiedSentence = inFromServer.readLine();
20         System.out.println("FROM SERVER: " + modifiedSentence);
21         clientSocket.close();
22     }
23 }

TCPServer

 1 package com.tcp;
 2 
 3 import java.io.*;
 4 import java.net.*;
 5 
 6 class TCPServer 
 7 {
 8    public static void main(String argv[]) throws Exception
 9       {
10          String clientSentence;
11          String capitalizedSentence;
12          ServerSocket welcomeSocket = new ServerSocket
13          (6789);
14 
15          while(true) 
16          {
17             Socket connectionSocket = welcomeSocket.accept();
18             
19             BufferedReader inFromClient =
　　　　　　　　　　　new BufferedReader
　　　　　　　　　　(new InputStreamReader(connectionSocket.getInputStream()));
20             
21             DataOutputStream outToClient =
　　　　　　　　　　　new DataOutputStream(connectionSocket.getOutputStream());
22             clientSentence = inFromClient.readLine();
23             capitalizedSentence =  clientSentence.toUpperCase() + '
';
24             outToClient.writeBytes(capitalizedSentence);
25          }
26       }
27 }

UDP

UDPClient

 1 package com.udp;
 2 
 3 import java.io.*;
 4 import java.net.*;
 5 
 6 class UDPClient 
 7 {
 8    public static void main(String args[]) throws Exception
 9    {
10       BufferedReader inFromUser =
　　　　　　　　new BufferedReader(new InputStreamReader(System.in));
11       DatagramSocket clientSocket = new DatagramSocket();
12       InetAddress IPAddress = InetAddress.getByName("localhost");
13       byte[] sendData = new byte[1024];
14       byte[] receiveData = new byte[1024];
15       String sentence = inFromUser.readLine();
16       sendData = sentence.getBytes();
17       DatagramPacket sendPacket =
　　　　　　　　new DatagramPacket(sendData, sendData.length, IPAddress, 9876);
18       clientSocket.send(sendPacket);
19       DatagramPacket receivePacket =
　　　　　　　　new DatagramPacket(receiveData,receiveData.length);
20       clientSocket.receive(receivePacket);
21       String modifiedSentence = new String(receivePacket.getData());
22       System.out.println("FROM SERVER:" +modifiedSentence);
23       clientSocket.close();
24    }
25 }

UDPServer

 1 package com.udp;
 2 
 3 import java.io.*;
 4 import java.net.*;
 5 
 6 class UDPServer 
 7 {
 8    public static void main(String args[]) throws Exception
 9       {
10          DatagramSocket serverSocket = new
11                               DatagramSocket(9876);
12             byte[] receiveData = new byte[1024];
13             byte[] sendData = new byte[1024];
14             while(true)
15                {
16                   DatagramPacket receivePacket =
　　　　　　　　　　　　　　new DatagramPacket(receiveData, receiveData.length);
17                   serverSocket.receive(receivePacket);
18                   String sentence = new String(receivePacket.getData());
19                   InetAddress IPAddress = receivePacket.getAddress();
20                   int port = receivePacket.getPort();
21                   String capitalizedSentence = sentence.toUpperCase();
22                   sendData = capitalizedSentence.getBytes();
23                   DatagramPacket sendPacket =
　　　　　　　　　　　　　　new DatagramPacket(sendData,sendData.length, IPAddress, port);
24                   serverSocket.send(sendPacket);
25                }
26       }
27 }