allowed classloader to be specified, to improve the flexibility of the types...

allowed classloader to be specified, to improve the flexibility of the types that can be used for getRemoteProperty()

remoting/src/main/java/hudson/remoting/Channel.java

@@ -305,6 +305,10 @@ public class Channel implements VirtualChannel, IChannel {
         this(name,exec,mode,is,os,header,false);
     }
 
+    public Channel(String name, ExecutorService exec, Mode mode, InputStream is, OutputStream os, OutputStream header, boolean restricted) throws IOException {
+        this(name,exec,mode,is,os,header,restricted,null);
+    }
+
     /**
      * Creates a new channel.
      *
@@ -325,6 +329,12 @@ public class Channel implements VirtualChannel, IChannel {
      *      the data goes into the "binary mode". This is useful
      *      when the established communication channel might include some data that might
      *      be useful for debugging/trouble-shooting.
+     * @param base
+     *      Specify the classloader used for deserializing remote commands.
+     *      This is primarily related to {@link #getRemoteProperty(Object)}. Sometimes two parties
+     *      communicate over a channel and pass objects around as properties, but those types might not be
+     *      visible from the classloader loading the {@link Channel} class. In such a case, specify a classloader
+     *      so that those classes resolve. If null, {@code Channel.class.getClassLoader()} is used.
      * @param restricted
      *      If true, this channel won't accept {@link Command}s that allow the remote end to execute arbitrary closures
      *      --- instead they can only call methods on objects that are exported by this channel.
@@ -334,15 +344,18 @@ public class Channel implements VirtualChannel, IChannel {
      *      (provided that all the classes are already available in this JVM), so exactly how
      *      safe the resulting behavior is is up to discussion.
      */
-    public Channel(String name, ExecutorService exec, Mode mode, InputStream is, OutputStream os, OutputStream header, boolean restricted) throws IOException {
-        this(name,exec,mode,is,os,header,restricted,new Capability());
+    public Channel(String name, ExecutorService exec, Mode mode, InputStream is, OutputStream os, OutputStream header, boolean restricted, ClassLoader base) throws IOException {
+        this(name,exec,mode,is,os,header,restricted,base,new Capability());
     }
 
-    /*package*/ Channel(String name, ExecutorService exec, Mode mode, InputStream is, OutputStream os, OutputStream header, boolean restricted, Capability capability) throws IOException {
+    /*package*/ Channel(String name, ExecutorService exec, Mode mode, InputStream is, OutputStream os, OutputStream header, boolean restricted, ClassLoader base, Capability capability) throws IOException {
         this.name = name;
         this.executor = exec;
         this.isRestricted = restricted;
 
+        if (base==null)
+            base = getClass().getClassLoader();
+
         if(export(this,false)!=1)
             throw new AssertionError(); // export number 1 is reserved for the channel itself
         remoteChannel = RemoteInvocationHandler.wrap(this,1,IChannel.class,false,false);
@@ -395,7 +408,7 @@ public class Channel implements VirtualChannel, IChannel {
                                 this.oos = oos;
                                 this.remoteCapability = cap;
                                 this.pipeWriter = createPipeWriter();
-                                this.ois = new ObjectInputStream(mode.wrap(is));
+                                this.ois = new ObjectInputStreamEx(mode.wrap(is),base);
                                 new ReaderThread(name).start();
 
                                 return;