package be.nikiroo.utils.serial.server; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.OutputStreamWriter; import java.net.Socket; import javax.net.ssl.SSLException; import be.nikiroo.utils.Version; import be.nikiroo.utils.serial.Exporter; import be.nikiroo.utils.serial.Importer; /** * Base class used for the client/server basic handling. *

* It represents a single action: a client is expected to only execute one * action, while a server is expected to execute one action for each client * action. * * @author niki */ abstract class ConnectAction { private Socket s; private boolean server; private Version version; private Version clientVersion; private Object lock = new Object(); private BufferedReader in; private OutputStreamWriter out; private boolean contentToSend; private long bytesReceived; private long bytesSent; /** * Method that will be called when an action is performed on either the * client or server this {@link ConnectAction} represent. * * @param version * the counter part version * * @throws Exception * in case of I/O error */ abstract protected void action(Version version) throws Exception; /** * Method called when we negotiate the version with the client. *

* Thus, it is only called on the server. *

* Will return the actual server version by default. * * @param clientVersion * the client version * * @return the version to send to the client */ abstract protected Version negotiateVersion(Version clientVersion); /** * Handler called when an unexpected error occurs in the code. * * @param e * the exception that occurred */ abstract protected void onError(Exception e); /** * Create a new {@link ConnectAction}. * * @param s * the socket to bind to * @param server * TRUE for a server action, FALSE for a client action (will * impact the process) * @param version * the version of this client-or-server */ protected ConnectAction(Socket s, boolean server, Version version) { this.s = s; this.server = server; if (version == null) { this.version = new Version(); } else { this.version = version; } clientVersion = new Version(); } /** * The version of this client-or-server. * * @return the version */ public Version getVersion() { return version; } /** * The total amount of bytes received. * * @return the amount of bytes received */ public long getBytesReceived() { return bytesReceived; } /** * The total amount of bytes sent. * * @return the amount of bytes sent */ public long getBytesSent() { return bytesSent; } /** * Actually start the process (this is synchronous). */ public void connect() { try { in = new BufferedReader(new InputStreamReader(s.getInputStream(), "UTF-8")); try { out = new OutputStreamWriter(s.getOutputStream(), "UTF-8"); try { if (server) { String line = in.readLine(); if (line != null && line.startsWith("VERSION ")) { // "VERSION client-version" (VERSION 1.0.0) Version clientVersion = new Version( line.substring("VERSION ".length())); this.clientVersion = clientVersion; Version v = negotiateVersion(clientVersion); if (v == null) { v = new Version(); } sendString("VERSION " + v.toString()); } action(clientVersion); } else { String v = sendString("VERSION " + version.toString()); if (v != null && v.startsWith("VERSION ")) { v = v.substring("VERSION ".length()); } action(new Version(v)); } } finally { out.close(); out = null; } } finally { in.close(); in = null; } } catch (Exception e) { if (e instanceof SSLException) { String ciphers = ""; for (String cipher : Server.getAnonCiphers()) { if (!ciphers.isEmpty()) { ciphers += ", "; } ciphers += cipher; } e = new SSLException("SSL error (available SSL ciphers: " + ciphers + ")", e); } onError(e); } finally { try { s.close(); } catch (Exception e) { onError(e); } } } /** * Serialise and send the given object to the counter part (and, only for * client, return the deserialised answer -- the server will always receive * NULL). * * @param data * the data to send * * @return the answer (which can be NULL) if this action is a client, always * NULL if it is a server * * @throws IOException * in case of I/O error * @throws NoSuchFieldException * if the serialised data contains information about a field * which does actually not exist in the class we know of * @throws NoSuchMethodException * if a class described in the serialised data cannot be created * because it is not compatible with this code * @throws ClassNotFoundException * if a class described in the serialised data cannot be found */ protected Object sendObject(Object data) throws IOException, NoSuchFieldException, NoSuchMethodException, ClassNotFoundException { synchronized (lock) { String rep = sendString(new Exporter().append(data).toString(true, true)); if (rep != null) { return new Importer().read(rep).getValue(); } return null; } } /** * Reserved for the server: flush the data to the client and retrieve its * answer. *

* Also used internally for the client (only do something if there is * contentToSend). *

* Will only flush the data if there is contentToSend. * * @return the deserialised answer (which can actually be NULL) * * @throws IOException * in case of I/O error * @throws NoSuchFieldException * if the serialised data contains information about a field * which does actually not exist in the class we know of * @throws NoSuchMethodException * if a class described in the serialised data cannot be created * because it is not compatible with this code * @throws ClassNotFoundException * if a class described in the serialised data cannot be found * @throws java.lang.NullPointerException * if the counter part has no data to send */ protected Object recObject() throws IOException, NoSuchFieldException, NoSuchMethodException, ClassNotFoundException, java.lang.NullPointerException { String str = recString(); if (str == null) { throw new NullPointerException("No more data available"); } return new Importer().read(str).getValue(); } /** * Send the given string to the counter part (and, only for client, return * the answer -- the server will always receive NULL). * * @param line * the data to send (we will add a line feed) * * @return the answer if this action is a client (without the added line * feed), NULL if it is a server * * @throws IOException * in case of I/O error */ protected String sendString(String line) throws IOException { synchronized (lock) { out.write(line); out.write("\n"); bytesSent += line.length() + 1; if (server) { out.flush(); return null; } contentToSend = true; return recString(); } } /** * Reserved for the server (externally): flush the data to the client and * retrieve its answer. *

* Also used internally for the client (only do something if there is * contentToSend). *

* Will only flush the data if there is contentToSend. * * @return the answer (which can be NULL) * * @throws IOException * in case of I/O error */ protected String recString() throws IOException { synchronized (lock) { if (server || contentToSend) { if (contentToSend) { out.flush(); contentToSend = false; } String line = in.readLine(); if (line != null) { bytesReceived += line.length(); } return line; } return null; } } }