GUACAMOLE-221: Expose underlying protocol of a GuacamoleSocket via getProtocol().

guacamole-common/src/main/java/org/apache/guacamole/net/DelegatingGuacamoleSocket.java

@@ -0,0 +1,84 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.guacamole.net;
+
+import org.apache.guacamole.GuacamoleException;
+import org.apache.guacamole.io.GuacamoleReader;
+import org.apache.guacamole.io.GuacamoleWriter;
+
+/**
+ * GuacamoleSocket implementation which simply delegates all function calls to
+ * an underlying GuacamoleSocket.
+ */
+public class DelegatingGuacamoleSocket implements GuacamoleSocket {
+
+    /**
+     * The wrapped socket.
+     */
+    private final GuacamoleSocket socket;
+
+    /**
+     * Wraps the given GuacamoleSocket such that all function calls against
+     * this DelegatingGuacamoleSocket will be delegated to it.
+     *
+     * @param socket
+     *     The GuacamoleSocket to wrap.
+     */
+    public DelegatingGuacamoleSocket(GuacamoleSocket socket) {
+        this.socket = socket;
+    }
+
+    /**
+     * Returns the underlying GuacamoleSocket wrapped by this
+     * DelegatingGuacamoleSocket.
+     *
+     * @return
+     *     The GuacamoleSocket wrapped by this DelegatingGuacamoleSocket.
+     */
+    protected GuacamoleSocket getDelegateSocket() {
+        return socket;
+    }
+
+    @Override
+    public String getProtocol() {
+        return socket.getProtocol();
+    }
+
+    @Override
+    public GuacamoleReader getReader() {
+        return socket.getReader();
+    }
+
+    @Override
+    public GuacamoleWriter getWriter() {
+        return socket.getWriter();
+    }
+
+    @Override
+    public void close() throws GuacamoleException {
+        socket.close();
+    }
+
+    @Override
+    public boolean isOpen() {
+        return socket.isOpen();
+    }
+
+}

guacamole-common/src/main/java/org/apache/guacamole/net/GuacamoleSocket.java

@@ -29,6 +29,24 @@ import org.apache.guacamole.io.GuacamoleWriter;
  */
 public interface GuacamoleSocket {
 
+    /**
+     * Returns the name of the protocol to be used. If the protocol is not
+     * known or the implementation refuses to reveal the underlying protocol,
+     * null is returned.
+     *
+     * <p>Implementations <strong>should</strong> aim to expose the name of the
+     * underlying protocol, such that protocol-specific responses like the
+     * "required" and "argv" instructions can be handled correctly by code
+     * consuming the GuacamoleSocket.
+     *
+     * @return
+     *     The name of the protocol to be used, or null if this information is
+     *     not available.
+     */
+    public default String getProtocol() {
+        return null;
+    }
+
     /**
      * Returns a GuacamoleReader which can be used to read from the
      * Guacamole instruction stream associated with the connection