ServerObject.java

   1 package be.nikiroo.utils.serial.server;
   2
   3 import java.io.IOException;
   4 import java.net.Socket;
   5 import java.net.UnknownHostException;
   6
   7 import be.nikiroo.utils.Version;
   8
   9 /**
  10  * This class implements a simple server that can listen for connections and
  11  * send/receive objects.
  12  * <p>
  13  * Note: this {@link ServerObject} has to be discarded after use (cannot be
  14  * started twice).
  15  *
  16  * @author niki
  17  */
  18 abstract public class ServerObject extends Server {
  19         /**
  20          * Create a new server that will start listening on the network when
  21          * {@link ServerObject#start()} is called.
  22          *
  23          * @param port
  24          *            the port to listen on, or 0 to assign any unallocated port
  25          *            found (which can later on be queried via
  26          *            {@link ServerObject#getPort()}
  27          * @param ssl
  28          *            use a SSL connection (or not)
  29          *
  30          * @throws IOException
  31          *             in case of I/O error
  32          * @throws UnknownHostException
  33          *             if the IP address of the host could not be determined
  34          * @throws IllegalArgumentException
  35          *             if the port parameter is outside the specified range of valid
  36          *             port values, which is between 0 and 65535, inclusive
  37          */
  38         public ServerObject(int port, boolean ssl) throws IOException {
  39                 super(port, ssl);
  40         }
  41
  42         /**
  43          * Create a new server that will start listening on the network when
  44          * {@link ServerObject#start()} is called.
  45          *
  46          * @param name
  47          *            the server name (only used for debug info and traces)
  48          * @param port
  49          *            the port to listen on
  50          * @param ssl
  51          *            use a SSL connection (or not)
  52          *
  53          * @throws IOException
  54          *             in case of I/O error
  55          * @throws UnknownHostException
  56          *             if the IP address of the host could not be determined
  57          * @throws IllegalArgumentException
  58          *             if the port parameter is outside the specified range of valid
  59          *             port values, which is between 0 and 65535, inclusive
  60          */
  61         public ServerObject(String name, int port, boolean ssl) throws IOException {
  62                 super(name, port, ssl);
  63         }
  64
  65         @Override
  66         protected ConnectActionServer createConnectActionServer(Socket s) {
  67                 return new ConnectActionServerObject(s) {
  68                         @Override
  69                         public void action(Version clientVersion) throws Exception {
  70                                 try {
  71                                         for (Object data = rec(); true; data = rec()) {
  72                                                 Object rep = null;
  73                                                 try {
  74                                                         rep = onRequest(this, clientVersion, data);
  75                                                 } catch (Exception e) {
  76                                                         onError(e);
  77                                                 }
  78                                                 send(rep);
  79                                         }
  80                                 } catch (NullPointerException e) {
  81                                         // Client has no data any more, we quit
  82                                 }
  83                         }
  84
  85                         @Override
  86                         protected void onError(Exception e) {
  87                                 ServerObject.this.onError(e);
  88                         }
  89                 };
  90         }
  91
  92         /**
  93          * This is the method that is called on each client request.
  94          * <p>
  95          * You are expected to react to it and return an answer (which can be NULL).
  96          *
  97          * @param action
  98          *            the client action
  99          * @param clientVersion
 100          *            the client version
 101          * @param data
 102          *            the data sent by the client (which can be NULL)
 103          *
 104          * @return the answer to return to the client (which can be NULL)
 105          *
 106          * @throws Exception
 107          *             in case of an exception, the error will only be logged
 108          */
 109         abstract protected Object onRequest(ConnectActionServerObject action,
 110                         Version clientVersion, Object data) throws Exception;
 111 }