Initial submit of 0-10 communication layer.

git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk/qpid@559151 13f79535-47bb-0310-9956-ffa450edef68

32 files changed, 1872 insertions, 0 deletions

diff --git a/java/common/generate b/java/common/generate
new file mode 100755
index 0000000000..698c9b6a0b
--- /dev/null
+++ b/java/common/generate
@@ -0,0 +1,226 @@
+#!/usr/bin/python
+
+# Interim code generation script.
+
+import sys, os
+from cStringIO import StringIO
+
+sys.path.append("../../python")
+
+import mllib
+
+out_dir=sys.argv[1]
+out_pkg = sys.argv[2]
+spec_file = sys.argv[3]
+spec = mllib.xml_parse(spec_file)
+major = spec["amqp"]["@major"]
+minor = spec["amqp"]["@minor"]
+isfx = "_v%s_%s" % (major, minor)
+
+class Output:
+
+  def __init__(self, dir, package, name):
+    self.dir = dir
+    self.package = package
+    self.name = name
+    self.lines = []
+
+  def line(self, l = None):
+    self.lines.append(l)
+
+  def write(self):
+    dir = os.path.join(self.dir, *self.package.split("."))
+    if not os.path.exists(dir):
+      os.makedirs(dir)
+    file = os.path.join(dir, "%s.java" % self.name)
+    out = open(file, "write")
+    print >> out, "package %s;" % self.package
+    print >> out
+    print >> out, "import java.util.Map;"
+    print >> out, "import java.util.UUID;"
+    print >> out
+    for l in self.lines:
+      if l == None:
+        print >> out
+      else:
+        print >> out, l
+    out.close()
+
+TYPES = {
+  "longstr": "String",
+  "shortstr": "String",
+  "longlong": "long",
+  "long": "int",
+  "short": "short",
+  "octet": "byte",
+  "bit": "boolean",
+  "table": "Map<String,?>",
+  "timestamp": "long",
+  "content": "String",
+  "uuid": "UUID",
+  "rfc1982-long-set": "Range<Integer>[]",
+  "rfc1982-long": "int"
+  }
+
+def camel(offset, *args):
+  parts = []
+  for a in args:
+    parts.extend(a.split("-"))
+  return "".join(parts[:offset] + [p.capitalize() for p in parts[offset:]])
+
+def dromedary(s):
+  return s[0].lower() + s[1:]
+
+DOMAINS = {}
+
+for d in spec.query["amqp/domain"]:
+  DOMAINS[d["@name"]] = d["@type"]
+
+def resolve(type):
+  if (DOMAINS.has_key(type)):
+    return resolve(DOMAINS[type])
+  else:
+    return type
+
+class Struct:
+
+  def __init__(self, type, name):
+    self.type = type
+    self.name = name
+    self.fields = []
+
+  def field(self, type, name):
+    self.fields.append((type, name))
+
+  def interface(self, out):
+    out.line("public interface %s extends Method {" % self.name)
+    out.line()
+    out.line("    public static final int TYPE = %d;" % self.type)
+    out.line()
+    for type, name in self.fields:
+      out.line("    %s %s();" % (TYPES[type], camel(1, "get", name)))
+    out.line()
+    out.line("}")
+
+  def impl(self, out):
+    out.line("class %s%s extends AbstractMethod implements %s {" %
+             (self.name, isfx, self.name))
+
+    out.line()
+    out.line("    public int getEncodingType() {")
+    out.line("        return TYPE;")
+    out.line("    }")
+
+    out.line()
+    for type, name in self.fields:
+      out.line("    private final %s %s;" % (TYPES[type], name))
+
+    out.line()
+    out.line("    %s%s(Decoder dec) {" % (self.name, isfx))
+    for type, name in self.fields:
+      out.line("        %s = dec.read%s();" % (name, camel(0, type)))
+    out.line("    }")
+
+    out.line()
+    out.line("    %s%s(%s) {" % (self.name, isfx, self.parameters()))
+    for type, name in self.fields:
+      out.line("    this.%s = %s;" % (name, name))
+    out.line("    }")
+
+    out.line()
+    out.line("    public <C> void delegate(C context, Delegate<C> delegate) {")
+    out.line("        delegate.%s(context, this);" % dromedary(self.name))
+    out.line("    }")
+
+    out.line()
+    for type, name in self.fields:
+      out.line("    public %s %s() {" % (TYPES[type], camel(1, "get", name)))
+      out.line("        return %s;" % name)
+      out.line("    }")
+
+    out.line()
+    out.line("    public void write(Encoder enc) {")
+    for type, name in self.fields:
+      out.line("        enc.write%s(%s);" % (camel(0, type), name))
+    out.line("    }")
+
+    out.line("}")
+
+
+  def parameters(self):
+    return ", ".join(["%s %s" % (TYPES[type], name) for type, name in self.fields])
+
+  def arguments(self):
+    return ", ".join([name for (type, name) in self.fields])
+
+structs = []
+for m in spec.query["amqp/class/method"]:
+  struct = Struct(int(m.parent["@index"])*256 + int(m["@index"]),
+                  camel(0, m.parent["@name"], m["@name"]))
+  for f in m.query["field"]:
+    struct.field(resolve(f["@domain"]), camel(1, f["@name"]))
+  structs.append(struct)
+  out = Output(out_dir, out_pkg, struct.name)
+  struct.interface(out)
+  out.write()
+  iout = Output(out_dir, out_pkg, struct.name + isfx)
+  struct.impl(iout)
+  iout.write()
+
+fct = Output(out_dir, out_pkg, "StructFactory")
+fct.line("public interface StructFactory {")
+fct.line("    Struct create(int type, Decoder dec);")
+for s in structs:
+  fct.line()
+  fct.line("    %s new%s(Decoder dec);" % (s.name, s.name))
+  fct.line("    %s new%s(%s);" % (s.name, s.name, s.parameters()))
+fct.line("}")
+fct.write()
+
+ifct_name = "StructFactory%s" % isfx
+ifct = Output(out_dir, out_pkg, ifct_name)
+ifct.line("class %s implements StructFactory {" % ifct_name)
+ifct.line("    public Struct create(int type, Decoder dec) {")
+ifct.line("        switch(type) {")
+for s in structs:
+  ifct.line("        case %s.TYPE:" % s.name)
+  ifct.line("            return new %s%s(dec);" % (s.name, isfx))
+ifct.line("        default:")
+ifct.line('            throw new IllegalArgumentException("type: " + type);')
+ifct.line("        }")
+ifct.line("    }")
+
+for s in structs:
+  ifct.line("    public %s new%s(Decoder dec) {" % (s.name, s.name))
+  ifct.line("        return new %s%s(dec);" % (s.name, isfx))
+  ifct.line("    }")
+
+  ifct.line("    public %s new%s(%s) {" % (s.name, s.name, s.parameters()))
+  ifct.line("        return new %s%s(%s);" % (s.name, isfx, s.arguments()))
+  ifct.line("    }")
+
+ifct.line("}");
+ifct.write()
+
+dlg = Output(out_dir, out_pkg, "Delegate")
+dlg.line("public abstract class Delegate<C> {")
+for s in structs:
+  dlg.line("    public void %s(C context, %s struct) {}" %
+           (dromedary(s.name), s.name))
+dlg.line("}")
+dlg.write()
+
+inv = Output(out_dir, out_pkg, "Invoker")
+inv.line("public abstract class Invoker {")
+inv.line()
+inv.line("    protected abstract void invoke(Method method);")
+inv.line("    protected abstract void invoke(Method method, Handler<Struct> handler);")
+inv.line("    protected abstract StructFactory getFactory();")
+inv.line()
+for s in structs:
+  dname = dromedary(s.name)
+  inv.line("    public void %s(%s) {" % (dname, s.parameters()))
+  inv.line("        invoke(getFactory().new%s(%s));" % (s.name, s.arguments()))
+  inv.line("    }")
+inv.line("}")
+inv.write()
diff --git a/java/common/pom.xml b/java/common/pom.xml
index a16573e066..a2b1089586 100644
--- a/java/common/pom.xml
+++ b/java/common/pom.xml
@@ -56,6 +56,12 @@
                         <configuration>
                             <tasks>
                                 <ant antfile="protocol-version.xml" />
+                                <exec executable="python">
+                                  <arg line="generate"/>
+                                  <arg line="${generated.path}"/>
+                                  <arg line="org.apache.qpidity"/>
+                                  <arg line="${specs.dir}/amqp-transitional.0-10.xml"/>
+                                </exec>
                             </tasks>
                             <sourceRoot>${generated.path}</sourceRoot>
                         </configuration>
diff --git a/java/common/src/main/java/org/apache/qpidity/AbstractMethod.java b/java/common/src/main/java/org/apache/qpidity/AbstractMethod.java
new file mode 100644
index 0000000000..663027e2d8
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/AbstractMethod.java
@@ -0,0 +1,31 @@
+/*
+ *
+ * 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.qpidity;
+
+import java.nio.ByteBuffer;
+
+/**
+ * AbstractMethod
+ *
+ * @author Rafael H. Schloming
+ */
+
+abstract class AbstractMethod implements Method {}
diff --git a/java/common/src/main/java/org/apache/qpidity/BBDecoder.java b/java/common/src/main/java/org/apache/qpidity/BBDecoder.java
new file mode 100644
index 0000000000..0a4c6ef063
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/BBDecoder.java
@@ -0,0 +1,109 @@
+/*
+ *
+ * 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.qpidity;
+
+import java.nio.ByteBuffer;
+
+import java.util.Map;
+import java.util.UUID;
+
+/**
+ * BBDecoder
+ *
+ * @author Rafael H. Schloming
+ */
+
+class BBDecoder implements Decoder
+{
+
+    private final ByteBuffer in;
+
+    public BBDecoder(ByteBuffer in) {
+        this.in = in;
+    }
+
+    public boolean readBit()
+    {
+        //throw new Error("TODO");
+        return false;
+    }
+
+    public byte readOctet()
+    {
+        throw new Error("TODO");
+    }
+
+    public short readShort()
+    {
+        return in.getShort();
+    }
+
+    public int readLong()
+    {
+        return in.getInt();
+    }
+
+    public long readLonglong()
+    {
+        throw new Error("TODO");
+    }
+
+    public long readTimestamp()
+    {
+        throw new Error("TODO");
+    }
+
+
+    public String readShortstr()
+    {
+        byte size = in.get();
+        byte[] bytes = new byte[size];
+        in.get(bytes);
+        return new String(bytes);
+    }
+
+    public String readLongstr()
+    {
+        throw new Error("TODO");
+    }
+
+    public Map<String,?> readTable()
+    {
+        //throw new Error("TODO");
+        return null;
+    }
+
+    public Range<Integer>[] readRfc1982LongSet()
+    {
+        throw new Error("TODO");
+    }
+
+    public UUID readUuid()
+    {
+        throw new Error("TODO");
+    }
+
+    public String readContent()
+    {
+        throw new Error("TODO");
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/BBEncoder.java b/java/common/src/main/java/org/apache/qpidity/BBEncoder.java
new file mode 100644
index 0000000000..36edf278f3
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/BBEncoder.java
@@ -0,0 +1,110 @@
+/*
+ *
+ * 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.qpidity;
+
+import java.nio.ByteBuffer;
+
+import java.util.Map;
+import java.util.UUID;
+
+/**
+ * BBEncoder
+ *
+ * @author Rafael H. Schloming
+ */
+
+class BBEncoder implements Encoder
+{
+
+    private final ByteBuffer out;
+
+    public BBEncoder(ByteBuffer out) {
+        this.out = out;
+    }
+
+    public void writeBit(boolean b)
+    {
+        //throw new Error("TODO");
+    }
+
+    public void writeOctet(byte b)
+    {
+        out.put(b);
+    }
+
+    public void writeShort(short s)
+    {
+        out.putShort(s);
+    }
+
+    public void writeLong(int i)
+    {
+        out.putInt(i);
+    }
+
+    public void writeLonglong(long l)
+    {
+        throw new Error("TODO");
+    }
+
+
+    public void writeTimestamp(long l)
+    {
+        throw new Error("TODO");
+    }
+
+
+    public void writeShortstr(String s)
+    {
+        if (s.length() > 255) {
+            throw new IllegalArgumentException(s);
+        }
+        writeOctet((byte) s.length());
+        out.put(s.getBytes());
+    }
+
+    public void writeLongstr(String s)
+    {
+        throw new Error("TODO");
+    }
+
+
+    public void writeTable(Map<String,?> table)
+    {
+        //throw new Error("TODO");
+    }
+
+    public void writeRfc1982LongSet(Range<Integer>[] ranges)
+    {
+        throw new Error("TODO");
+    }
+
+    public void writeUuid(UUID uuid)
+    {
+        throw new Error("TODO");
+    }
+
+    public void writeContent(String c)
+    {
+        throw new Error("TODO");
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/BodyHandler.java b/java/common/src/main/java/org/apache/qpidity/BodyHandler.java
new file mode 100644
index 0000000000..0b772c6f04
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/BodyHandler.java
@@ -0,0 +1,38 @@
+/*
+ *
+ * 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.qpidity;
+
+
+/**
+ * BodyHandler
+ *
+ * @author Rafael H. Schloming
+ */
+
+class BodyHandler<C> implements Handler<Event<C,Frame>>
+{
+
+    public void handle(Event<C,Frame> event)
+    {
+        System.out.println("got body frame: " + event.target);
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Channel.java b/java/common/src/main/java/org/apache/qpidity/Channel.java
new file mode 100644
index 0000000000..a9060622e8
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Channel.java
@@ -0,0 +1,91 @@
+/*
+ *
+ * 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.qpidity;
+
+
+/**
+ * Channel
+ *
+ * @author Rafael H. Schloming
+ */
+
+class Channel extends Invoker
+    implements Handler<Frame>, DelegateResolver<Channel>
+{
+
+    final private Connection connection;
+    final private TrackSwitch<Channel> tracks;
+
+
+    // session may be null
+    private Session session;
+
+    public Channel(Connection connection)
+    {
+        this.connection = connection;
+        tracks = new TrackSwitch<Channel>();
+        tracks.map(Frame.L1, new MethodHandler<Channel>());
+        tracks.map(Frame.L2, new MethodHandler<Channel>());
+        tracks.map(Frame.L3, new SessionResolver<Frame>(new MethodHandler<Session>()));
+        tracks.map(Frame.L4, new SessionResolver<Frame>(new ContentHandler<Session>()));
+    }
+
+    public Session getSession()
+    {
+        return session;
+    }
+
+    void setSession(Session session)
+    {
+        this.session = session;
+    }
+
+    public void handle(Frame frame)
+    {
+        tracks.handle(new Event<Channel,Frame>(this, frame));
+    }
+
+    public void write(Writable writable)
+    {
+        System.out.println("writing: " + writable);
+    }
+
+    protected StructFactory getFactory()
+    {
+        return connection.getFactory();
+    }
+
+    public Delegate<Channel> resolve(Struct struct)
+    {
+        return new ChannelDelegate();
+    }
+
+    protected void invoke(Method m)
+    {
+        write(m);
+    }
+
+    protected void invoke(Method m, Handler<Struct> handler)
+    {
+        throw new UnsupportedOperationException();
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Connection.java b/java/common/src/main/java/org/apache/qpidity/Connection.java
new file mode 100644
index 0000000000..bb8b945051
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Connection.java
@@ -0,0 +1,59 @@
+/*
+ *
+ * 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.qpidity;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Connection
+ *
+ * @author Rafael H. Schloming
+ *
+ * @todo the channels map should probably be replaced with something
+ * more efficient, e.g. an array or a map implementation that can use
+ * short instead of Short
+ */
+
+class Connection implements Handler<Frame>
+{
+
+    final private Map<Short,Channel> channels = new HashMap<Short,Channel>();
+    final private StructFactory factory = new StructFactory_v0_10();
+
+    public void handle(Frame frame)
+    {
+        Channel channel = channels.get(frame.getChannel());
+        if (channel == null)
+        {
+            channel = new Channel(this);
+            channels.put(frame.getChannel(), channel);
+        }
+
+        channel.handle(frame);
+    }
+
+    public StructFactory getFactory()
+    {
+        return factory;
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/ContentHandler.java b/java/common/src/main/java/org/apache/qpidity/ContentHandler.java
new file mode 100644
index 0000000000..ea73a3574d
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/ContentHandler.java
@@ -0,0 +1,42 @@
+/*
+ *
+ * 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.qpidity;
+
+
+/**
+ * ContentHandler is a stateful handler that aggregates and dispatches
+ * method and header frames, and passes body frames through to another
+ * handler.
+ *
+ * @author Rafael H. Schloming
+ */
+
+class ContentHandler<C extends DelegateResolver<C>> extends TypeSwitch<C>
+{
+
+    public ContentHandler()
+    {
+        map(Frame.METHOD, new SegmentAssembler<C>(new MethodDispatcher<C>()));
+        map(Frame.HEADER, new SegmentAssembler<C>(new HeaderHandler<C>()));
+        map(Frame.BODY, new BodyHandler<C>());
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Decoder.java b/java/common/src/main/java/org/apache/qpidity/Decoder.java
new file mode 100644
index 0000000000..5001d3ebee
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Decoder.java
@@ -0,0 +1,52 @@
+/*
+ *
+ * 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.qpidity;
+
+import java.util.Map;
+import java.util.UUID;
+
+/**
+ * Decoder
+ *
+ * @author Rafael H. Schloming
+ */
+
+public interface Decoder
+{
+
+    boolean readBit();
+    byte readOctet();
+    short readShort();
+    int readLong();
+    long readLonglong();
+
+    long readTimestamp();
+
+    String readShortstr();
+    String readLongstr();
+
+    Map<String,?> readTable();
+    Range<Integer>[] readRfc1982LongSet();
+    UUID readUuid();
+
+    String readContent();
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/DelegateResolver.java b/java/common/src/main/java/org/apache/qpidity/DelegateResolver.java
new file mode 100644
index 0000000000..632781847e
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/DelegateResolver.java
@@ -0,0 +1,36 @@
+/*
+ *
+ * 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.qpidity;
+
+
+/**
+ * A DelegateResolver locates the desired delegate to use for handling
+ * a given Struct.
+ *
+ * @author Rafael H. Schloming
+ */
+
+interface DelegateResolver<C>
+{
+
+    Delegate<C> resolve(Struct struct);
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Delegator.java b/java/common/src/main/java/org/apache/qpidity/Delegator.java
new file mode 100644
index 0000000000..00e769e0f2
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Delegator.java
@@ -0,0 +1,35 @@
+/*
+ *
+ * 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.qpidity;
+
+
+/**
+ * Delegator
+ *
+ * @author Rafael H. Schloming
+ */
+
+interface Delegator
+{
+
+    <C> void delegate(C context, Delegate<C> delegate);
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Encoder.java b/java/common/src/main/java/org/apache/qpidity/Encoder.java
new file mode 100644
index 0000000000..27360a551a
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Encoder.java
@@ -0,0 +1,52 @@
+/*
+ *
+ * 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.qpidity;
+
+import java.util.Map;
+import java.util.UUID;
+
+/**
+ * Encoder
+ *
+ * @author Rafael H. Schloming
+ */
+
+public interface Encoder
+{
+
+    void writeBit(boolean b);
+    void writeOctet(byte b);
+    void writeShort(short s);
+    void writeLong(int i);
+    void writeLonglong(long l);
+
+    void writeTimestamp(long l);
+
+    void writeShortstr(String s);
+    void writeLongstr(String s);
+
+    void writeTable(Map<String,?> table);
+    void writeRfc1982LongSet(Range<Integer>[] ranges);
+    void writeUuid(UUID uuid);
+
+    void writeContent(String c);
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Event.java b/java/common/src/main/java/org/apache/qpidity/Event.java
new file mode 100644
index 0000000000..ae210f4c20
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Event.java
@@ -0,0 +1,44 @@
+/*
+ *
+ * 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.qpidity;
+
+
+/**
+ * Events are a common class of thing to handle. An event has a
+ * context and a target. This division permits the same target
+ * instance to be used in a variety of contexts.
+ *
+ * @author Rafael H. Schloming
+ */
+
+public class Event<C, T>
+{
+
+    C context;
+    T target;
+
+    public Event(C context, T target)
+    {
+        this.context = context;
+        this.target = target;
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Frame.java b/java/common/src/main/java/org/apache/qpidity/Frame.java
new file mode 100644
index 0000000000..298400d511
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Frame.java
@@ -0,0 +1,135 @@
+/*
+ *
+ * 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.qpidity;
+
+import java.nio.ByteBuffer;
+import java.nio.ShortBuffer;
+
+/**
+ * Frame
+ *
+ * @author Rafael H. Schloming
+ */
+
+class Frame
+{
+
+    public static final short L1 = 0;
+    public static final short L2 = 1;
+    public static final short L3 = 2;
+    public static final short L4 = 3;
+
+    public static final short METHOD = 1;
+    public static final short HEADER = 2;
+    public static final short BODY = 3;
+
+    final private short channel;
+    final private short track;
+    final private short type;
+    final private boolean firstSegment;
+    final private boolean lastSegment;
+    final private boolean firstFrame;
+    final private boolean lastFrame;
+    final private ByteBuffer payload;
+
+    // XXX
+    final private int sequence = 0;
+
+    public Frame(short channel, short track, short type, boolean firstSegment,
+                 boolean lastSegment, boolean firstFrame, boolean lastFrame,
+                 ByteBuffer payload)
+    {
+        this.channel = channel;
+        this.track = track;
+        this.type = type;
+        this.firstSegment = firstSegment;
+        this.lastSegment = lastSegment;
+        this.firstFrame = firstFrame;
+        this.lastFrame = lastFrame;
+        this.payload = payload;
+    }
+
+    public short getChannel()
+    {
+        return channel;
+    }
+
+    public short getTrack()
+    {
+        return track;
+    }
+
+    public short getType()
+    {
+        return type;
+    }
+
+    public boolean isFirstSegment()
+    {
+        return firstSegment;
+    }
+
+    public boolean isLastSegment()
+    {
+        return lastSegment;
+    }
+
+    public boolean isFirstFrame()
+    {
+        return firstFrame;
+    }
+
+    public boolean isLastFrame()
+    {
+        return lastFrame;
+    }
+
+    public ByteBuffer getPayload()
+    {
+        return payload.slice();
+    }
+
+    public int getSize()
+    {
+        return payload.remaining();
+    }
+
+    public String toString()
+    {
+        StringBuilder str = new StringBuilder();
+        str.append(String.format
+                   ("[%05d %05d %1d %1d %d%d%d%d]", channel, track, type,
+                    getSize(),
+                    firstSegment ? 1 : 0, lastSegment ? 1 : 0,
+                    firstFrame ? 1 : 0, lastFrame ? 1 : 0));
+        ShortBuffer shorts = payload.asShortBuffer();
+        for (int i = 0; i < shorts.limit(); i++) {
+            str.append(String.format(" %04x", shorts.get(i)));
+            if (str.length() > 70) {
+                str.append(" ...");
+                break;
+            }
+        }
+
+        return str.toString();
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Handler.java b/java/common/src/main/java/org/apache/qpidity/Handler.java
new file mode 100644
index 0000000000..0ff949cc1d
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Handler.java
@@ -0,0 +1,35 @@
+/*
+ *
+ * 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.qpidity;
+
+/**
+ * Handler is a basic interface used throughout this library for
+ * callbacks, listeners, event handlers, etc.
+ *
+ * @author Rafael H. Schloming
+ */
+
+public interface Handler<E>
+{
+
+    void handle(E event);
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Header.java b/java/common/src/main/java/org/apache/qpidity/Header.java
new file mode 100644
index 0000000000..1d494c6d41
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Header.java
@@ -0,0 +1,30 @@
+/*
+ *
+ * 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.qpidity;
+
+
+/**
+ * Header
+ *
+ * @author Rafael H. Schloming
+ */
+
+interface Header extends Struct {}
diff --git a/java/common/src/main/java/org/apache/qpidity/HeaderHandler.java b/java/common/src/main/java/org/apache/qpidity/HeaderHandler.java
new file mode 100644
index 0000000000..a63c032e38
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/HeaderHandler.java
@@ -0,0 +1,38 @@
+/*
+ *
+ * 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.qpidity;
+
+
+/**
+ * HeaderHandler
+ *
+ * @author Rafael H. Schloming
+ */
+
+class HeaderHandler<C> implements Handler<Event<C,Segment>>
+{
+
+    public void handle(Event<C,Segment> event)
+    {
+        System.out.println("got header segment:\n  " + event.target);
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Method.java b/java/common/src/main/java/org/apache/qpidity/Method.java
new file mode 100644
index 0000000000..12a7b48f94
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Method.java
@@ -0,0 +1,34 @@
+/*
+ *
+ * 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.qpidity;
+
+
+/**
+ * Method
+ *
+ * @author Rafael H. Schloming
+ */
+
+interface Method extends Struct {
+
+    int getEncodingType();
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/MethodDispatcher.java b/java/common/src/main/java/org/apache/qpidity/MethodDispatcher.java
new file mode 100644
index 0000000000..a2a4ebb0fc
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/MethodDispatcher.java
@@ -0,0 +1,48 @@
+/*
+ *
+ * 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.qpidity;
+
+import java.nio.ByteBuffer;
+
+/**
+ * A MethodDispatcher parses and dispatches a method segment.
+ *
+ * @author Rafael H. Schloming
+ */
+
+class MethodDispatcher<C extends DelegateResolver<C>>
+    implements Handler<Event<C,Segment>>
+{
+
+    // XXX: should be passed in
+    final private StructFactory factory = new StructFactory_v0_10();
+
+    public void handle(Event<C,Segment> event)
+    {
+        System.out.println("got method segment:\n  " + event.target);
+        ByteBuffer bb = event.target.getPayload();
+        int type = bb.getInt();
+        Struct struct = factory.create(type, new BBDecoder(bb));
+        Delegate<C> delegate = event.context.resolve(struct);
+        struct.delegate(event.context, delegate);
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/MethodHandler.java b/java/common/src/main/java/org/apache/qpidity/MethodHandler.java
new file mode 100644
index 0000000000..ebc7471622
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/MethodHandler.java
@@ -0,0 +1,40 @@
+/*
+ *
+ * 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.qpidity;
+
+
+/**
+ * MethodHandler is a stateful handler that aggregates frames into
+ * method segments and dispatches the resulting method. It does not
+ * accept any segment type other than Frame.METHOD.
+ *
+ * @author Rafael H. Schloming
+ */
+
+class MethodHandler<C extends DelegateResolver<C>> extends TypeSwitch<C>
+{
+
+    public MethodHandler()
+    {
+        map(Frame.METHOD, new SegmentAssembler<C>(new MethodDispatcher<C>()));
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Range.java b/java/common/src/main/java/org/apache/qpidity/Range.java
new file mode 100644
index 0000000000..4766ecb471
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Range.java
@@ -0,0 +1,51 @@
+/*
+ *
+ * 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.qpidity;
+
+
+/**
+ * Range
+ *
+ * @author Rafael H. Schloming
+ */
+
+public class Range<C extends Comparable>
+{
+    private final C lower;
+    private final C upper;
+
+    public Range(C lower, C upper)
+    {
+        this.lower = lower;
+        this.upper = upper;
+    }
+
+    public C getLower()
+    {
+        return lower;
+    }
+
+    public C getUpper()
+    {
+        return upper;
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Segment.java b/java/common/src/main/java/org/apache/qpidity/Segment.java
new file mode 100644
index 0000000000..cd1d4ab05d
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Segment.java
@@ -0,0 +1,80 @@
+/*
+ *
+ * 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.qpidity;
+
+import java.nio.ByteBuffer;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+/**
+ * Segment
+ *
+ * @author Rafael H. Schloming
+ */
+
+class Segment
+{
+
+    private final Collection<Frame> frames = new ArrayList<Frame>();
+
+    public void add(Frame frame)
+    {
+        frames.add(frame);
+    }
+
+    public ByteBuffer getPayload()
+    {
+        // we should probably use our own decoder interface here so
+        // that we can directly read from the incoming frame objects
+        // and automatically skip frame boundaries without copying
+        // everything in order to get a contiguous byte buffer
+        int capacity = 0;
+        for (Frame frame : frames)
+        {
+            capacity += frame.getSize();
+        }
+        ByteBuffer buf = ByteBuffer.allocate(capacity);
+        for (Frame frame : frames)
+        {
+            buf.put(frame.getPayload());
+        }
+        buf.flip();
+        return buf;
+    }
+
+    public String toString()
+    {
+        StringBuffer buf = new StringBuffer();
+        String sep = ",\n  ";
+
+        for (Frame f : frames)
+        {
+            buf.append(f.toString());
+            buf.append(sep);
+        }
+
+        buf.setLength(buf.length() - sep.length());
+
+        return buf.toString();
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/SegmentAssembler.java b/java/common/src/main/java/org/apache/qpidity/SegmentAssembler.java
new file mode 100644
index 0000000000..2d47e760c1
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/SegmentAssembler.java
@@ -0,0 +1,61 @@
+/*
+ *
+ * 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.qpidity;
+
+import java.nio.ByteBuffer;
+
+/**
+ * SegmentAssembler is a stateful handler that aggregates Frame events
+ * into Segment events. This should only be used where it is necessary
+ * to assemble a Segment before processing, e.g. for Method and Header
+ * segments.
+ *
+ * @author Rafael H. Schloming
+ */
+
+class SegmentAssembler<C> implements Handler<Event<C,Frame>>
+{
+
+    final private Handler<Event<C,Segment>> handler;
+    private Segment segment;
+
+    public SegmentAssembler(Handler<Event<C,Segment>> handler)
+    {
+        this.handler = handler;
+    }
+
+    public void handle(Event<C, Frame> event)
+    {
+        Frame frame = event.target;
+        if (frame.isFirstFrame())
+        {
+            segment = new Segment();
+        }
+
+        segment.add(frame);
+
+        if (frame.isLastFrame())
+        {
+            handler.handle(new Event<C, Segment>(event.context, segment));
+        }
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Session.java b/java/common/src/main/java/org/apache/qpidity/Session.java
new file mode 100644
index 0000000000..32da625070
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Session.java
@@ -0,0 +1,70 @@
+/*
+ *
+ * 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.qpidity;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Session
+ *
+ * @author Rafael H. Schloming
+ */
+
+public class Session extends Invoker implements DelegateResolver<Session>
+{
+
+    // channel may be null
+    Channel channel;
+    private int command_id = 0;
+    // XXX
+    final Map<Integer,Handler<Struct>> handlers = new HashMap<Integer,Handler<Struct>>();
+    final private Delegate<Session> delegate = new SessionDelegate();
+
+    public void attach(Channel channel)
+    {
+        this.channel = channel;
+        channel.setSession(this);
+    }
+
+    protected void invoke(Method m)
+    {
+        command_id++;
+        channel.write(m);
+    }
+
+    protected void invoke(Method m, Handler<Struct> handler)
+    {
+        invoke(m);
+        handlers.put(command_id, handler);
+    }
+
+    protected StructFactory getFactory()
+    {
+        return channel.getFactory();
+    }
+
+    public Delegate<Session> resolve(Struct struct)
+    {
+        return delegate;
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/SessionResolver.java b/java/common/src/main/java/org/apache/qpidity/SessionResolver.java
new file mode 100644
index 0000000000..24e52839fd
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/SessionResolver.java
@@ -0,0 +1,47 @@
+/*
+ *
+ * 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.qpidity;
+
+
+/**
+ * SessionResolver is a stateless handler that accepts incoming events
+ * whose context is a Channel, and produces an event whose context is
+ * a Session.
+ *
+ * @author Rafael H. Schloming
+ */
+
+class SessionResolver<T> implements Handler<Event<Channel,T>>
+{
+
+    final private Handler<Event<Session,T>> handler;
+
+    public SessionResolver(Handler<Event<Session,T>> handler)
+    {
+        this.handler = handler;
+    }
+
+    public void handle(Event<Channel,T> event)
+    {
+        handler.handle(new Event<Session,T>(event.context.getSession(), event.target));
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Struct.java b/java/common/src/main/java/org/apache/qpidity/Struct.java
new file mode 100644
index 0000000000..6d9913b042
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Struct.java
@@ -0,0 +1,30 @@
+/*
+ *
+ * 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.qpidity;
+
+
+/**
+ * Struct
+ *
+ * @author Rafael H. Schloming
+ */
+
+interface Struct extends Delegator, Writable {}
diff --git a/java/common/src/main/java/org/apache/qpidity/Stub.java b/java/common/src/main/java/org/apache/qpidity/Stub.java
new file mode 100644
index 0000000000..d8de56f8b1
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Stub.java
@@ -0,0 +1,78 @@
+package org.apache.qpidity;
+
+import java.nio.ByteBuffer;
+import java.util.*;
+import java.lang.annotation.*;
+
+public class Stub {
+
+    private static Connection conn = new Connection();
+
+    private static void frame(short track, short type, boolean first, boolean last) {
+        frame(track, type, first, last, null);
+    }
+
+    private static void frame(short track, short type, boolean first, boolean last, Method m) {
+        ByteBuffer buf = ByteBuffer.allocate(512);
+        if (m != null) {
+            buf.putInt(m.getEncodingType());
+            m.write(new BBEncoder(buf));
+        }
+        buf.flip();
+        Frame frame = new Frame((short)0, track, type, true, true, first, last, buf);
+        conn.handle(frame);
+    }
+
+    public static final void main(String[] args) {
+        StructFactory f = new StructFactory_v0_10();
+        frame(Frame.L2, Frame.METHOD, true, true, f.newSessionOpen(0));
+        frame(Frame.L4, Frame.METHOD, true, false, f.newQueueDeclare((short) 0, "asdf", "alternate", false, false, false, false, false, null));
+        frame(Frame.L4, Frame.METHOD, false, false);
+        frame(Frame.L3, Frame.METHOD, true, true, f.newExchangeDeclare((short) 0, "exchange", "type", "alternate", false, false, false, null));
+        frame(Frame.L4, Frame.METHOD, false, true);
+        frame(Frame.L4, Frame.HEADER, true, false);
+        frame(Frame.L4, Frame.HEADER, false, false);
+        frame(Frame.L4, Frame.HEADER, false, true);
+        frame(Frame.L4, Frame.BODY, true, false);
+        frame(Frame.L4, Frame.BODY, false, false);
+        frame(Frame.L4, Frame.BODY, false, false);
+        frame(Frame.L1, Frame.METHOD, true, true, f.newExchangeDeclare((short) 0, "exchange", "type", "alternate", false, false, false, null));
+        frame(Frame.L4, Frame.BODY, false, false);
+        frame(Frame.L4, Frame.BODY, false, true);
+    }
+
+}
+
+//====: Channel and Session Delegates :=======================================//
+
+class ChannelDelegate extends Delegate<Channel> {
+
+    public @Override void sessionOpen(Channel channel, SessionOpen open) {
+        Session ssn = new Session();
+        ssn.attach(channel);
+        System.out.println("Session Open");
+    }
+
+}
+
+class SessionDelegate extends Delegate<Session> {
+
+    public @Override void queueDeclare(Session session, QueueDeclare qd) {
+        System.out.println("got a queue declare: " + qd.getQueue());
+    }
+
+    public @Override void exchangeDeclare(Session session, ExchangeDeclare ed) {
+        System.out.println("got an exchange declare: " + ed.getExchange() + ", " + ed.getType());
+        session.queueDeclare((short) 0, "asdf", "alternate", false, false, false, false, false, null);
+    }
+
+    /*
+    public @Override void executionResult(Session session, ExecutionResult result) {
+        Handler<Struct> handler = session.handlers.get(result.getCommandId());
+        if (handler != null) {
+            handler.handle(result.getData());
+        }
+        }
+    */
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Switch.java b/java/common/src/main/java/org/apache/qpidity/Switch.java
new file mode 100644
index 0000000000..a84ae1507b
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Switch.java
@@ -0,0 +1,52 @@
+/*
+ *
+ * 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.qpidity;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * A Switch performs generic event dispatch.
+ *
+ * @author Rafael H. Schloming
+ */
+
+abstract class Switch<K,E> implements Handler<E>
+{
+
+    final private Map<K,Handler<E>> handlers =
+        new HashMap<K,Handler<E>>();
+
+    public void map(K key, Handler<E> handler)
+    {
+        handlers.put(key, handler);
+    }
+
+    public void handle(E event)
+    {
+        K key = resolve(event);
+        Handler<E> handler = handlers.get(key);
+        handler.handle(event);
+    }
+
+    abstract K resolve(E event);
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/TrackSwitch.java b/java/common/src/main/java/org/apache/qpidity/TrackSwitch.java
new file mode 100644
index 0000000000..c9b3cda032
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/TrackSwitch.java
@@ -0,0 +1,39 @@
+/*
+ *
+ * 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.qpidity;
+
+
+/**
+ * A TrackSwitch sends incoming frames to a different handler based on
+ * track.
+ *
+ * @author Rafael H. Schloming
+ */
+
+class TrackSwitch<C> extends Switch<Short,Event<C,Frame>>
+{
+
+    public Short resolve(Event<C,Frame> event)
+    {
+        return event.target.getTrack();
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/TypeSwitch.java b/java/common/src/main/java/org/apache/qpidity/TypeSwitch.java
new file mode 100644
index 0000000000..a5073486c7
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/TypeSwitch.java
@@ -0,0 +1,39 @@
+/*
+ *
+ * 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.qpidity;
+
+
+/**
+ * A TypeSwitch sends incoming frames to a different handler based on
+ * type.
+ *
+ * @author Rafael H. Schloming
+ */
+
+class TypeSwitch<C> extends Switch<Short,Event<C,Frame>>
+{
+
+    public Short resolve(Event<C,Frame> event)
+    {
+        return event.target.getType();
+    }
+
+}
diff --git a/java/common/src/main/java/org/apache/qpidity/Writable.java b/java/common/src/main/java/org/apache/qpidity/Writable.java
new file mode 100644
index 0000000000..9554da880a
--- /dev/null
+++ b/java/common/src/main/java/org/apache/qpidity/Writable.java
@@ -0,0 +1,34 @@
+/*
+ *
+ * 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.qpidity;
+
+/**
+ * Writable
+ *
+ * @author Rafael H. Schloming
+ */
+
+interface Writable
+{
+
+    void write(Encoder enc);
+
+}