Java Network Programming using socket (1)

Java supports stream-based communication and packet-based Communication,and the first is universal.
Create ServerSocket
1.Create serversocket

ServerSocket serversocket=new ServerSocket (port);

2.Listen to the Connect

Socket socket=serversocket.accept ();

3.We need create inputstream and outputstream to transmit data

InputStream Inputfromclient=socket.getinputsream ();
OutputStream Outputtoclient=socket.getoutputstream ();

(We can also use DataInputStream and DataOutputStream, BufferedReader and PrintWriter to get the data types is int,double and string.)

Create Client Socket
1.Create Client Socket

Socket socket=new socket (servername,port);

(The serverName can be host name or the host IP address.)
2.We need create inputstream and outputstream to transmit data

Inputsream Inputfromserver=socket.getinputstream ();
OutputStream Outputtoserver=socket.getoutputstream ();

(We can also use DataInputStream and DataOutputStream, BufferedReader and PrintWriter to get the data type is int,double or string.)

Now,there is a example that Client send radius to server and server compute area and return to Client.

Server.java

ImportJava.awt.BorderLayout;ImportJava.io.DataInputStream;ImportJava.io.DataOutputStream;ImportJava.io.IOException;ImportJava.net.ServerSocket;ImportJava.net.Socket;ImportJava.util.Date;ImportJavax.swing.JFrame;ImportJavax.swing.JScrollPane;ImportJavax.swing.JTextArea; Public  class Server extends JFrame {    PrivateJTextArea Jta=NewJTextArea (); Public Static void Main(string[] args) {NewServer (); } Public Server() {setlayout (NewBorderLayout ()); AddNewJScrollPane (JTA), borderlayout.center); Settitle ("Server"); SetSize ( -, -);        Setdefaultcloseoperation (Jframe.exit_on_close); SetVisible (true);Try{//create a server socketServerSocket serversocket=NewServerSocket (8000); Jta.append ("Server started at"+NewDate () +"\ n");//listen for a connection requestSocket socket=serversocket.accept ();//create data input and output streamsDataInputStream inputfromclient=NewDataInputStream (Socket.getinputstream ()); DataOutputStream outputtoclient=NewDataOutputStream (Socket.getoutputstream ()); while(true) {//receive radius from the client                DoubleRadius=inputfromclient.readdouble ();//compute Area                DoubleArea=radius*radius*math.pi;//send area back to the clientOutputtoclient.writedouble (area); Jta.append ("Radius received from client:"+radius +' \ n '); Jta.append ("area found:"+area+' \ n '); }        }Catch(IOException ex)        {System.err.println (ex); }    }}

Client.java

ImportJava.awt.BorderLayout;ImportJava.awt.event.ActionEvent;ImportJava.awt.event.ActionListener;ImportJava.io.DataInputStream;ImportJava.io.DataOutputStream;ImportJava.io.IOException;Importjava.net.InetAddress;ImportJava.net.Socket;ImportJavax.swing.JFrame;ImportJavax.swing.JLabel;ImportJavax.swing.JPanel;ImportJavax.swing.JScrollPane;ImportJavax.swing.JTextArea;ImportJavax.swing.JTextField; Public  class Client extends JFrame {    //text filed for receiving RADIUS    PrivateJTextField jtf=NewJTextField ();//text area to display contents    PrivateJTextArea Jta=NewJTextArea ();//io streams    PrivateDataOutputStream Toserver;PrivateDataInputStream fromserver; Public Static void Main(string[] args) {NewClient (); } Public Client(){//panel Panel to hold the label and text fieldJPanel panel=NewJPanel (); Panel.setlayout (NewBorderLayout ()); Panel.add (NewJLabel ("Enter radius"), borderlayout.west);        Panel.add (Jtf,borderlayout.center);        Jtf.sethorizontalalignment (Jtextfield.right); SetLayout (NewBorderLayout ());        Add (Panel,borderlayout.north); AddNewJScrollPane (JTA), borderlayout.center); Jtf.addactionlistener (NewTextfieldlistener ()); Settitle ("Client"); SetSize ( -, -);        Setdefaultcloseoperation (Jframe.exit_on_close); SetVisible (true);//it is necessary to show the frame here        Try{//create a socket to connect to the serverSocket socket=NewSocket ("localhost",8000);//socket Socket =new socket ("130.254.204.36", 8000);            //socket Socket =new socket ("Drake. Armstrong.edu ", 8000);System.out.println ("Local port:"+socket.getlocalport ());//test inetaddressInetAddress inetaddress=socket.getinetaddress (); System.out.println ("Client s host name is"+inetaddress.gethostname ()); System.out.println ("Client's IP address is"+inetaddress.gethostaddress ());//            //create an input stream to receive data from the serverFromserver=NewDataInputStream (Socket.getinputstream ());//create an output stream to send data from the serverToserver=NewDataOutputStream (Socket.getoutputstream ()); }Catch(IOException ex) {Jta.append (ex.tostring () +' \ n '); }    }Private  class Textfieldlistener implements ActionListener{         Public void actionperformed(ActionEvent e) {Try{//get the radius from the text field                DoubleRadius=double.parsedouble (Jtf.gettext (). Trim ());//send The RADIUS to the serverToserver.writedouble (RADIUS); Toserver.flush ();//get area from the server                DoubleArea=fromserver.readdouble ();//display to the text serverJta.append ("Radius is"+radius+"\ n"); Jta.append ("area received from the server is"+area +' \ n '); }Catch(IOException ex)            {System.err.println (ex); }        }    }}

Java Network Programming using socket (1)