Học web giới thiệu tiếp tục bài tập lập trình service tính toán 2 số bằng UDP
Code trên server
/*
*tinh tong 2 so a + b gui tu CLient len server
* tren Client can tao 2 goi gui 2 so a va b , va tao 1 goi de nhan 1 ket qua ve
* tren Server can tao 2 goi nhan 2 so a va b, va tao 1 goi de gui ket qua ve
*/
package UDP_home;
import java.io.DataInputStream;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.UnknownHostException;
/**
*
* @author Nguyen Anh Tuan
*/
public class Client {
public static void main(String []args) throws IOException
{
//tao moi socket client
DatagramSocket ClientSocket = new DatagramSocket();
System.out.println("Connected to server");
//nhap yeu cau tu nguoi dung
DataInputStream inFromUser = new DataInputStream(System.in);
int a,b,tong;
try
{
System.out.println("Nhap vao so a :");
a = Integer.parseInt(inFromUser.readLine());
System.out.println("Nhap vao so b :");
b = Integer.parseInt(inFromUser.readLine());
//Khai bao mang byte de chua du lieu gui di server
byte outToServer1[];
byte outToServer2[];
//chuyen kieu du lieu : int -> String
String s1 = String.valueOf(a);
String s2 = String.valueOf(b);
//chuyen kieu du lieu : String -> byte va dua vao mang byte da khai bao o tren
outToServer1 = s1.getBytes();
outToServer2 = s2.getBytes();
//lay kich thuoc cua mang
int leng1 = outToServer1.length;
int leng2 = outToServer2.length;
//dia chi may chu
InetAddress address = InetAddress.getByName("Localhost");
// so port
int port = 1024;
// tao goi de gui di
DatagramPacket toServer1 = new DatagramPacket(outToServer1, leng1, address, port);
DatagramPacket toServer2 = new DatagramPacket(outToServer2, leng2, address, port);
// gui goi len server
ClientSocket.send(toServer1);
ClientSocket.send(toServer2);
//tao goi de nhan du lieu ve
byte inFromServer[];
inFromServer = new byte[256];
//kich thuoc mang nhan du lieu ve
leng1 = inFromServer.length;
// tao goi nhan du lieu ve
DatagramPacket fromServer = new DatagramPacket(inFromServer, leng1);
// nhan goi tra ve tu server
ClientSocket.receive(fromServer);
//khai bao bien de chuyen tu kieu byte sang kieu String
String data;
// dua du lieu tu mang byte vao bien data, lay tu vi tri so 0.
data = (new String(fromServer.getData(),0,fromServer.getLength())).trim();
//in ket qua ra man hinh
System.out.println("Ket Qua :"+data);
ClientSocket.close();
}catch (UnknownHostException e)
{
System.out.println("Server Not Found");
System.exit(1);
}catch (IOException e)
{
System.out.println("Cannot connect to server");
System.exit(1);
}
}
}
Code trên client:
/*
*tinh tong 2 so a + b gui tu CLient len server
* tren Client can tao 2 goi gui 2 so a va b , va tao 1 goi de nhan 1 ket qua ve
* tren Server can tao 2 goi nhan 2 so a va b, va tao 1 goi de gui ket qua ve
*/
package UDP_home;
import java.io.DataInputStream;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.UnknownHostException;
/**
*
* @author Nguyen Anh Tuan
*/
public class Client {
public static void main(String []args) throws IOException
{
//tao moi socket client
DatagramSocket ClientSocket = new DatagramSocket();
System.out.println("Connected to server");
//nhap yeu cau tu nguoi dung
DataInputStream inFromUser = new DataInputStream(System.in);
int a,b,tong;
try
{
System.out.println("Nhap vao so a :");
a = Integer.parseInt(inFromUser.readLine());
System.out.println("Nhap vao so b :");
b = Integer.parseInt(inFromUser.readLine());
//Khai bao mang byte de chua du lieu gui di server
byte outToServer1[];
byte outToServer2[];
//chuyen kieu du lieu : int -> String
String s1 = String.valueOf(a);
String s2 = String.valueOf(b);
//chuyen kieu du lieu : String -> byte va dua vao mang byte da khai bao o tren
outToServer1 = s1.getBytes();
outToServer2 = s2.getBytes();
//lay kich thuoc cua mang
int leng1 = outToServer1.length;
int leng2 = outToServer2.length;
//dia chi may chu
InetAddress address = InetAddress.getByName("Localhost");
// so port
int port = 1024;
// tao goi de gui di
DatagramPacket toServer1 = new DatagramPacket(outToServer1, leng1, address, port);
DatagramPacket toServer2 = new DatagramPacket(outToServer2, leng2, address, port);
// gui goi len server
ClientSocket.send(toServer1);
ClientSocket.send(toServer2);
//tao goi de nhan du lieu ve
byte inFromServer[];
inFromServer = new byte[256];
//kich thuoc mang nhan du lieu ve
leng1 = inFromServer.length;
// tao goi nhan du lieu ve
DatagramPacket fromServer = new DatagramPacket(inFromServer, leng1);
// nhan goi tra ve tu server
ClientSocket.receive(fromServer);
//khai bao bien de chuyen tu kieu byte sang kieu String
String data;
// dua du lieu tu mang byte vao bien data, lay tu vi tri so 0.
data = (new String(fromServer.getData(),0,fromServer.getLength())).trim();
//in ket qua ra man hinh
System.out.println("Ket Qua :"+data);
ClientSocket.close();
}catch (UnknownHostException e)
{
System.out.println("Server Not Found");
System.exit(1);
}catch (IOException e)
{
System.out.println("Cannot connect to server");
System.exit(1);
}
}
}