Java Network Programming 2

package cn.itcast.tcp;import java.io.fileoutputstream;import java.io.ioexception;import  java.io.inputstream;import java.net.inetaddress;import java.net.socket;import  java.net.unknownhostexception;//download picture of client public class imageclient {     Public static void main (String[] args)  throws Exception{         //establishing a TCP service         socket socket =  new socket (Inetaddress.getlocalhost (), 9090);         // Gets the input stream object of the socket         InputStream inputStream =  Socket.getinputstream ();         //gets the output stream object of the file          fileoutputstream fileoutputstream = new fileoutputstream ("F:\\3. JPG ");         //Read and write         byte[] buf = new byte[1024];         int length = 0 ;                  while ((length =  Inputstream.read (BUF))!=-1) {             Fileoutputstream.write (buf,0,length);        }         //Close Resource         fileoutputstream.close ();         socket.close ();     }}

package cn.itcast.tcp;import java.io.fileinputstream;import java.io.filenotfoundexception; Import java.io.ioexception;import java.io.outputstream;import java.net.serversocket;import  java.net.Socket;import java.util.HashSet;/*1.  writing a server can send pictures to multiple clients.   (multithreading) */public class imageserver extends thread {    socket The collection used by  socket ;    //is used to store IP addresses.     static HashSet<String> ips = new HashSet<String> ( );     public  imageserver (Socket socket)  {     this.socket = socket;    }     @Override      public void run ()  {        try {             //gets the socket output stream object              outputstream outputstream = socket.getoutputstream ()             //gets the input stream object of the picture              FileInputStream fileInputStream = new  FileInputStream ("f:\\ Belle \\3.jpg");             // Read the image data and write the data out             byte[] buf =  new byte[1024];            int  Length = 0 ;             while ((Length = fileinputstream.read (BUF))!=-1) {                 Outputstream.write (buf,0,length);             }            string ip =  Socket.getinetaddress (). gethostaddress ();    // socket.getinetaddress ()   Get the IP address of each other             if (Ips.add (IP)) {                 system.out.println ("Congratulations" +ip+ " Students successfully downloaded, the current number of downloads is: "+ ips.size ());             }             //Close Resources              fileinputstream.close ();             socket.close ();             }catch  (ioexception e)  {        }     }   &Nbsp;public static void main (String[] args)  throws IOException {         //establish TCP service   and listen to a port          serversocket serversocket  = new serversocket (9090);         while (true) {            // Accept the user's link.             Socket socket =  Serversocket.accept ();            new  Imageserver (socket). Start ();         }    }}

package cn.itcast.tcp;import java.io.bufferedreader;import java.io.ioexception;import  java.io.inputstreamreader;import java.io.outputstreamwriter;import java.net.inetaddress;import  java.net.socket;/*2.   implements login and registration   function.    Client connection with the server, it is necessary to prompt the client please select the function. Client registration, the user name and password are sent to the server  , the server needs to save the data to the server side of the file. Login:  Login When the client input user name and password sent to the server, the server needs to verify, return the results to the client. */public class loginclinet {    public static void main ( String[] args)  throws ioexception {        socket  socket = new socket (Inetaddress.getlocalhost (), 9090);         //gets the output stream object of the socket         OutputStreamWriter   Socketout = new outputstreamwriter (Socket.getoutputstream ());         //gets the input stream object to the socket     &NBSp;   bufferedreader socketreader = new bufferedreader (new  InputStreamReader (Socket.getinputstream ()))         //gets the input stream object to the keyboard         BufferedReader keyReader = new  BufferedReader (New inputstreamreader (system.in));         while ( true) {            system.out.println ("Please select the function:  A (login)   b (registration) ");            string  Option = keyreader.readline ();                         if ("a". EqualsIgnoreCase (option)) {                getinfo ( socketout, keyreader, option);                 //read the information of server feedback                  string line  = socketreader.readline ();                 system.out.println (line);             }else if ("B". Equalsignorecase (option)) {                 getinfo (socketout, keyreader, option);                 //read the information of server feedback                  String line =  Socketreader.readline ();                 system.out.println(line);            }         }    }    public static void getinfo ( Outputstreamwriter  socketout,bufferedreader keyreader, string option)  throws  ioexception {        system.out.println ("Please enter user name:");         string username = keyreader.readline ();         system.out.println ("Please enter password:");         string password = keyreader.readline ();         string info = option + " " +username+ " " +password+ "\ r \ n";         socketout.write (info);         socketout.flush ( );     }} 

package cn.itcast.tcp;import java.io.bufferedreader;import java.io.file;import  java.io.filereader;import java.io.filewriter;import java.io.ioexception;import  Java.io.inputstreamreader;import java.io.outputstreamwriter;import java.net.serversocket;import  java.net.Socket;import java.util.Properties;public class LoginServer extends  Thread {    socket socket;    static file file  = new file ("F:\\users.properties");         public  loginserver (Socket socket)  {        this.socket =  socket;    }    static {         try {            if  (! File.exists ())  {      &Nbsp;         file.createnewfile ();             }        } catch  ( Ioexception e)  {             E.printstacktrace ();           }     }     @Override     public void run ()  {         while (True) {             try {            //  Gets the input stream object of the socket             BufferedReader  Bufferedreader = new bufferedreader (             new inputstreamreader (SOcket.getinputstream ()));                       //  get the output stream object of the socket              outputstreamwriter socketout = new outputstreamwriter ( Socket.getoutputstream ());            //  Read the client input information             string info =  bufferedreader.readline ();             string [] datas = info.split (" ");             //  get to User   selection features              string option = datas[0];             //  Registration             string username = datas[1];             String password = datas[2];             if  ("a". Equalsignorecase (option))   {                //  Login                 properties  properties = new properties ();                 //  Load configuration Files                  properties.load (New filereader (file));                 if  (Properties.containskey ( UserName))  {  &NBsp;             string temppass =  properties.getproperty (UserName);                 if  (Password.equals (temppass))  {                 socketout.write ("Welcome"  + userName +   "landing success \ r \ n");             } else {             socketout.write ("password error \ r \ n");             }             } else {             socketout.write ("User name does not exist, please reenter ... \ r \ n");             }  &nbsP;         socketout.flush ();             } else if  ("B". Equalsignorecase (option))  {             //  Create a configuration file class              properties properties = new properties ();             //loading the original configuration file              properties.load (New filereader (file));             if  (!properties.containskey (userName))  {             //  does not exist for this user name              properties.setproperty (Username, password);             //  generate a configuration file              properties.store (new filewriter (file),  "users");             socketout.write ("Registered successfully: \ r \ n ");            } else {             //  There is a user name              socketout.write ("User name has been registered, please re-enter \ r \ n");             }             Socketout.flush ();            }             } catch  (exception e)  {             e.printstacktraCE ();            }         }    }    public static void main ( String[] args)  throws IOException {         Serversocket serversocket = new serversocket (9090);         while  (True)  {             Socket socket = serversocket.accept ();             new loginserver (socket). Start ();        }     }}

This article from "Small Fish Blog" blog, declined reprint!

Java Network Programming 2