De bai:TCP DOi chuoi Client //TCP2C.java import java.io.*; import java.net.*; class TCP2C{ public static void main(String[] args) { Socket cl=null; BufferedReader inp=null,key=null; PrintWriter outp=null; String s; String ipserver="localhost"; int pserver=3456; //begin try{ cl=new Socket(ipserver,pserver); inp=new BufferedReader( new InputStreamReader(cl.getInputStream())); outp=new PrintWriter(cl.getOutputStream(),true); key=new BufferedReader( new InputStreamReader(System.in)); while(true) { System.out.print("Nhap chuoi:"); s=key.readLine().trim(); outp.println(s); if(s.equalsIgnoreCase("Quit")) break; s=inp.readLine(); System.out.println("ket qua nhan tu server:"+s); } } catch(IOException e) { System.out.println(e); } finally { if(cl!=null) cl=null; } } }

//TCPServer.java import java.net.*; import java.io.*; class TCPServer{ public static void main(String[] args) { ServerSocket svr=null; Socket cl=null; BufferedReader inp=null; PrintWriter outp=null; String s; int pserver=3456; InetAddress addr; int pclient; try{ //Tao doi tuong ServerSocket svr=new ServerSocket(pserver); //Dat svr o trang thai "nghe", neu co tin hieu ket noi // tra ve socket cl cl=svr.accept(); //Tao luong nhap xuat cho cl inp=new BufferedReader(new InputStreamReader(cl.getInputStream())); outp=new PrintWriter(cl.getOutputStream(),true); //Lay dia chi client addr=cl.getInetAddress(); pclient=cl.getPort(); //nhan chuoi tu client gui toi s=inp.readLine().trim(); System.out.println("Thong tin cllient:"); System.out.println("-Name:"+addr.getHostName()); System.out.println("-IP:"+addr.getHostAddress()); System.out.println("-Port:"+pclient); System.out.println("Data:"+s); s=s.toUpperCase(); //gui chuoi ve client outp.println(s); System.out.println("Da gui chuoi "+s+" ve client"); inp.close(); outp.close(); cl.close(); svr.close(); } catch(IOException e) { System.out.println(e); } } }