Xtykutl

I have 5 client classes and a server class (mutilthread). I have set the policy file through setProperty method but I'm not sure how to implement. I tried with check permission but it did not work for me. Is there any way that I can implement to check permission for which client has access and who does not based on the policy file?

Policy file

/* AUTOMATICALLY GENERATED ON Thu Nov 08 19:52:58 GST 2018*/

/* DO NOT EDIT */



grant{

    permission java.io.FilePermission"D:\Uni\System security\Client 

    Server Example\ClientServerExample\src\javaapplication2\abc.txt", 

    "read",signedBy"client1";



    permission java.io.FilePermission"D:\Uni\System security\Client Server Example\ClientServerExample\src\javaapplication2\abc.txt","write",signedBy"client2";



    };

eg: client1 has access to everything

client2 can only write

client 3 can only read

Server code

public class Server {



@SuppressWarnings("resource")

public static void main( String args ) throws IOException, InterruptedException

{

    ServerSocket socket = null;

    DataInputStream in;

    PrintStream out;

    Socket clientSocket1 = null;



    System.setProperty( "java.security.policy", "file:/C:/Users/Ali/Desktop/java.policy" );



    while ( true )

    {

        socket = new ServerSocket( 285 );

        System.out.println( "Server is Awaiting" );

        clientSocket1 = socket.accept();



        in = new DataInputStream( ( clientSocket1 ).getInputStream() );//read from client1

        BufferedReader fileRead = new BufferedReader( new InputStreamReader( in ) );

        String fname = fileRead.readLine();



        try

        {



            BufferedReader contentRead = new BufferedReader( new FileReader( fname ) );

            out = new PrintStream( clientSocket1.getOutputStream() );//write to client1

            PrintWriter pwrite = new PrintWriter( out, true );



            String str;

            while ( ( str = contentRead.readLine() ) != null )

            {

                pwrite.println( str );         // sending each line to client

            }



        }

        catch ( SecurityException e )

        {

        }

        Multi t = new Multi( clientSocket1 );

        t.start();

        Thread.sleep( 2000 );

        socket.close();

    }

}}