Bài tập môn lập trình mạng - Cách 2

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<b>BÀI T</b>

<b>Ậ</b>

<b>P </b>

<b>ð</b>

<b>I</b>

<b>Ề</b>

<b>U KI</b>

<b>Ệ</b>

<b>N </b>

Môn : L

<b>Ậ</b>

<b>P TRÌNH M</b>

<b>Ạ</b>

<b>NG </b>

(cách 2)

<b>CÂU H</b>

<b>Ỏ</b>

<b>I </b>

Gi

ả

i ph

ươ

ng trình b

ậ

c 2 dùng giao th

ứ

c TCP: Client g

ở

i pt b

ậ

c 2

→

Server gi

ả

i.

Client nh

ậ

p A, B, C g

ở

i cho Server, Server gi

ả

i xong g

ở

i k

ế

t qu

ả

v

ề

cho Client.

<b>BÀI LÀM </b>

Gi

ả

s

ử

máy Server có tên là

<b>thienthanh</b>

. Server k

ế

t n

ố

i

ở

c

ổ

ng

<b>1234</b>

.

*

ð

o

ạ

n ch

ươ

ng trình t

ạ

i Server nh

ư

sau:

<b>Server.java </b>

package baitap3;

import java.io.*;
import java.net.*;
import java.util.*;

public class Server {

public static ServerSocket servsock ;
public static final int PORT = 1234;
public static void main(String[] args)

{

try
{

/* Tao doi tuong ServerSocket dung de lang nghe ket noi
tu cac may client gui den cong 1234 */

servsock = new ServerSocket(PORT);

int localPort = servsock.getLocalPort();

System.out.println("\n Server dang mo port " +localPort+".");
}

catch(IOException ioEx)
{

System.out.println("\n Khong mo duoc port: " +PORT);
System.exit(1);

}
do
{

handleClient();
}while(true);
}

public static void handleClient()
{

Socket clientsock = null;
String kq = "";

try
{

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/* Co ket noi xay ra. Lay cac thong tin tu may client in ra man hinh
*/

//lay ten may client

String hostname = clientsock.getInetAddress().getHostName();
// lay dia chi IP cua may client

String destAdd = clientsock.getInetAddress().getHostAddress();
// lay cong cua may client

int destPort = clientsock.getPort();

System.out.println(" Chap nhan ket noi tu "+hostname+"
("+destAdd+") tai port "+destPort+".");

PrintWriter out = new PrintWriter(clientsock.getOutputStream(),
true);

BufferedReader in = new BufferedReader(new
InputStreamReader(clientsock.getInputStream()));

while (true)
{

String aStr=in.readLine();

System.out.println("\n Nhan tu Client ("+hostname+") gia tri A =
"+aStr);

if (aStr.equalsIgnoreCase("quit")) break;
String bStr=in.readLine();

System.out.println(" Nhan tu Client ("+hostname+") gia tri B =
"+bStr);

if (bStr.equalsIgnoreCase("quit")) break;
String cStr=in.readLine();

System.out.println(" Nhan tu Client ("+hostname+") gia tri C =
"+cStr);

if (cStr.equalsIgnoreCase("quit")) break;
float a,b,c;

try{

a = Float.parseFloat(aStr);

b = Float.parseFloat(bStr);
c = Float.parseFloat(cStr);
}catch(NumberFormatException e)

{out.println(" So khong hop le");continue;}
if (a==0)

if (b==0)

if (c==0) kq=" Ph/trinh co vo so nghiem";
else

kq=" Ph/trinh vo nghiem";

else kq=" Ph/trinh co nghiem x="+(- c/b);
else

{

double delta = b*b-4*a*c;

double x1 = (-b+Math.sqrt(delta))/(2*a);
double x2 = (-b-Math.sqrt(delta))/(2*a);

if (delta>0) kq = " Ph/trinh co 2 nghiem: x1="+x1+",
x2="+x2;

else

if (delta==0) kq= " Ph/trinh co nghiem kep:

x1=x2="+(-b/(2*a));

else kq=" Ph/trinh vo nghiem";
}

System.out.println("Ket qua:" +kq);
out.println("Ket qua tu Server:" +kq);
}

}

catch(IOException ioEx)
{

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}

finally
{
try
{

clientsock.close();
servsock.close();

System.out.println("\n Da ngat ket noi, thoat khoi chuong
trinh");

System.exit(1);

}

catch(IOException ioEx)
{

System.out.println("\n Khong ngat duoc ket noi!");
System.exit(1);

}
}
}
}

*

ð

o

ạ

n ch

ươ

ng trình t

ạ

i Client nh

ư

sau:

<b>Client.java </b>

package baitap3;

import java.io.*;
import java.net.*;
import java.util.*;
public class Client {

public static void main(String[] args) {
try{

/* Gia su ten may chu la thienthanh,

co the thay bang dia chi IP cua may Server */

Socket clientsock = new Socket("thienthanh", 1234);

PrintWriter out = new PrintWriter(clientsock.getOutputStream(), true);
BufferedReader in = new BufferedReader(new

InputStreamReader(clientsock.getInputStream()));
BufferedReader stdIn = new BufferedReader(new
InputStreamReader(System.in));

System.out.println("\n ---");
System.out.println(" Giai phuong trinh bac hai dung giao thuc TCP");
System.out.println(" ---");
System.out.println(" Hay cho biet gia tri cua A, B va C hoac type QUIT
de thoat");

while (true)
{

System.out.print("\n Nhap vao he so A = ");
String aStr = stdIn.readLine();

out.println(aStr);

//So sanh chuoi nhan duoc. Neu la "quit" thi ket thuc
if (aStr.equalsIgnoreCase("quit")) break;

System.out.print(" Nhap vao he so B = ");
String bStr = stdIn.readLine();

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//So sanh chuoi nhan duoc. Neu la "quit" thi ket thuc
if (bStr.equalsIgnoreCase("quit")) break;

System.out.print(" Nhap vao he so C = ");
String cStr = stdIn.readLine();

out.println(cStr);

//So sanh chuoi nhan duoc. Neu la "quit" thi ket thuc
if (cStr.equalsIgnoreCase("quit")) break;

System.out.println(in.readLine());
}

// Dong luong va ngat ket noi
out.close();

in.close();

clientsock.close();

System.out.println("\n Da ngat ket noi khoi Server, thoat khoi
chuong trinh");

System.exit(1);
}catch(IOException e){

//Neu co loi thi in ra man hinh
System.out.println(e);

System.exit(1);
}

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