diff --git a/README.md b/README.md
index eecff9e..8755f1e 100644
--- a/README.md
+++ b/README.md
@@ -27,10 +27,10 @@
  to retrieve data from the network. For example:
 ```
 // retrieve a single Data packet synchronously, will block until complete
-Data singleData = SimpleClient.getDefault().getSync(face, name);
+Data singleData = SimpleClient.getDefault().getSync(face, prefix);
 
-// retrieve segmented Data packets (i.e. with a last Component containing a segment number and a valid FinalBlockId) by name
-CompletableFuture<Data> segmentedData = AdvancedClient.getDefault().getAsync(face, name);
+// retrieve segmented Data packets (i.e. with a last Component containing a segment number and a valid FinalBlockId) by prefix
+CompletableFuture<Data> segmentedData = AdvancedClient.getDefault().getAsync(face, prefix);
 ```
 
 Use `SimpleServer` or `SegmentedServer` to serve data on the network. For example:
diff --git a/pom.xml b/pom.xml
index 9ef8dbd..323a19c 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
   <groupId>com.intel.jndn.utils</groupId>
   <artifactId>jndn-utils</artifactId>
   <version>1.0.4</version>
-  <name>jndn-utils</name>
+  <prefix>jndn-utils</prefix>
   <description>Collection of tools to simplify synchronous and asynchronous data transfer over the NDN network
   </description>
   <url>https://github.com/01org/jndn-utils</url>
@@ -14,14 +14,14 @@
 
   <licenses>
     <license>
-      <name>LGPL v3</name>
+      <prefix>LGPL v3</prefix>
       <url>https://www.gnu.org/licenses/lgpl.html</url>
     </license>
   </licenses>
 
   <developers>
     <developer>
-      <name>Andrew Brown</name>
+      <prefix>Andrew Brown</prefix>
       <url>http://github.com/andrewsbrown</url>
     </developer>
   </developers>
diff --git a/src/main/java/com/intel/jndn/utils/Publisher.java b/src/main/java/com/intel/jndn/utils/Publisher.java
new file mode 100644
index 0000000..7755b5c
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/Publisher.java
@@ -0,0 +1,24 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils;
+
+import net.named_data.jndn.util.Blob;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+public interface Publisher {
+  void publish(Blob message);
+}
diff --git a/src/main/java/com/intel/jndn/utils/Repository.java b/src/main/java/com/intel/jndn/utils/Repository.java
index fcc0172..6e314f4 100644
--- a/src/main/java/com/intel/jndn/utils/Repository.java
+++ b/src/main/java/com/intel/jndn/utils/Repository.java
@@ -20,7 +20,7 @@
 /**
  * Define API for storing and retrieving NDN packets
  *
- * @author Andrew Brown <andrew.brown@intel.com>
+ * @author Andrew Brown, andrew.brown@intel.com
  */
 public interface Repository {
 
@@ -29,7 +29,7 @@
    *
    * @param data a {@link Data} packet
    */
-  public void put(Data data);
+  void put(Data data);
 
   /**
    * Retrieve a {@link Data} packet in the repository; this method should
@@ -39,7 +39,7 @@
    * @return a {@link Data} packet
    * @throws DataNotFoundException if the packet is not found
    */
-  public Data get(Interest interest) throws DataNotFoundException;
+  Data get(Interest interest) throws DataNotFoundException;
 
   /**
    * Check if this repository can satisfy the {@link Interest} with a
@@ -49,10 +49,10 @@
    * @param interest the {@link Interest} to attempt to satisfy
    * @return true if a {@link Data} exists that satisfies the {@link Interest}
    */
-  public boolean satisfies(Interest interest);
+  boolean satisfies(Interest interest);
 
   /**
    * Remove all stale {@link Data} packets from the repository.
    */
-  public void cleanup();
+  void cleanup();
 }
diff --git a/src/main/java/com/intel/jndn/utils/Subscriber.java b/src/main/java/com/intel/jndn/utils/Subscriber.java
new file mode 100644
index 0000000..4949826
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/Subscriber.java
@@ -0,0 +1,26 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils;
+
+import com.intel.jndn.utils.pubsub.Cancellation;
+import com.intel.jndn.utils.pubsub.On;
+import net.named_data.jndn.util.Blob;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+public interface Subscriber {
+  Cancellation subscribe(On<Blob> onMessage, On<Exception> onError);
+}
diff --git a/src/main/java/com/intel/jndn/utils/client/DataStream.java b/src/main/java/com/intel/jndn/utils/client/DataStream.java
index 7f33870..3f517a3 100644
--- a/src/main/java/com/intel/jndn/utils/client/DataStream.java
+++ b/src/main/java/com/intel/jndn/utils/client/DataStream.java
@@ -1,6 +1,6 @@
 /*
  * jndn-utils
- * Copyright (c) 2015, Intel Corporation.
+ * Copyright (c) 2016, Intel Corporation.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU Lesser General Public License,
@@ -22,6 +22,8 @@
  * Define a stream of {@link Data} packets as they are retrieved from the
  * network and provide methods for observing stream events
  *
+ * TODO merge with Observable
+ *
  * @author Andrew Brown <andrew.brown@intel.com>
  */
 public interface DataStream extends OnData, OnTimeout, OnComplete, OnException {
@@ -29,47 +31,47 @@
   /**
    * @return true if the stream is complete
    */
-  public boolean isComplete();
+  boolean isComplete();
 
   /**
    * @return the current list of packets retrieved; this may change as more
    * packets are added
    */
-  public Data[] list();
+  Data[] list();
 
   /**
    * @return an assembled packet containing the concatenated bytes of all
    * received packets
    * @throws StreamException if assembly fails
    */
-  public Data assemble() throws StreamException;
+  Data assemble() throws StreamException;
 
   /**
    * Watch all {@link OnData} events
    *
    * @param onData the callback fired
    */
-  public void observe(OnData onData);
+  void observe(OnData onData);
 
   /**
    * Watch all {@link OnComplete} events
    *
    * @param onComplete the callback fired
    */
-  public void observe(OnComplete onComplete);
+  void observe(OnComplete onComplete);
 
   /**
    * Watch all {@link OnException} events
    *
    * @param onException the callback fired
    */
-  public void observe(OnException onException);
+  void observe(OnException onException);
 
   /**
    * Watch all {@link OnTimeout} events
    *
    * @param onTimeout the callback fired
    */
-  public void observe(OnTimeout onTimeout);
+  void observe(OnTimeout onTimeout);
 
 }
diff --git a/src/main/java/com/intel/jndn/utils/client/RetryClient.java b/src/main/java/com/intel/jndn/utils/client/RetryClient.java
index 9a5dacb..b559802 100644
--- a/src/main/java/com/intel/jndn/utils/client/RetryClient.java
+++ b/src/main/java/com/intel/jndn/utils/client/RetryClient.java
@@ -1,6 +1,6 @@
 /*
  * jndn-utils
- * Copyright (c) 2015, Intel Corporation.
+ * Copyright (c) 2016, Intel Corporation.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU Lesser General Public License,
@@ -13,16 +13,17 @@
  */
 package com.intel.jndn.utils.client;
 
-import java.io.IOException;
 import net.named_data.jndn.Face;
 import net.named_data.jndn.Interest;
 import net.named_data.jndn.OnData;
 import net.named_data.jndn.OnTimeout;
 
+import java.io.IOException;
+
 /**
  * Define a client that can retry {@link Interest} packets on timeout.
  *
- * @author Andrew Brown <andrew.brown@intel.com>
+ * @author Andrew Brown, andrew.brown@intel.com
  */
 public interface RetryClient {
 
@@ -40,5 +41,5 @@
    * @param onTimeout the application's failure callback
    * @throws IOException when the client cannot perform the necessary network IO
    */
-  public void retry(Face face, Interest interest, OnData onData, OnTimeout onTimeout) throws IOException;
+  void retry(Face face, Interest interest, OnData onData, OnTimeout onTimeout) throws IOException;
 }
diff --git a/src/main/java/com/intel/jndn/utils/pubsub/AnnouncementService.java b/src/main/java/com/intel/jndn/utils/pubsub/AnnouncementService.java
new file mode 100644
index 0000000..34818a4
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/pubsub/AnnouncementService.java
@@ -0,0 +1,27 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils.pubsub;
+
+import java.io.IOException;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+public interface AnnouncementService {
+  void announceEntrance(long id) throws IOException;
+  void announceExit(long id) throws IOException;
+  Cancellation discoverExistingAnnouncements(On<Long> onFound, On<Void> onComplete, On<Exception> onError);
+  Cancellation observeNewAnnouncements(On<Long> onAdded, On<Long> onRemoved, On<Exception> onError) throws RegistrationFailureException;
+}
diff --git a/src/main/java/com/intel/jndn/utils/pubsub/BlobContentStore.java b/src/main/java/com/intel/jndn/utils/pubsub/BlobContentStore.java
new file mode 100644
index 0000000..823bd85
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/pubsub/BlobContentStore.java
@@ -0,0 +1,49 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils.pubsub;
+
+import net.named_data.jndn.Face;
+import net.named_data.jndn.Name;
+import net.named_data.jndn.util.Blob;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+class BlobContentStore implements ContentStore<Blob> {
+  @Override
+  public void put(Name name, Blob data) {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public boolean has(Name name) {
+    return false;
+  }
+
+  @Override
+  public Blob get(Name name) {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public void push(Face face, Name name) {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public void clear() {
+    throw new UnsupportedOperationException();
+  }
+}
diff --git a/src/main/java/com/intel/jndn/utils/pubsub/Cancellation.java b/src/main/java/com/intel/jndn/utils/pubsub/Cancellation.java
new file mode 100644
index 0000000..2fe42df
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/pubsub/Cancellation.java
@@ -0,0 +1,24 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils.pubsub;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+public interface Cancellation {
+  Cancellation CANCELLED = () -> {/* do nothing */};
+
+  void cancel();
+}
diff --git a/src/main/java/com/intel/jndn/utils/pubsub/ContentStore.java b/src/main/java/com/intel/jndn/utils/pubsub/ContentStore.java
new file mode 100644
index 0000000..34c6ac0
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/pubsub/ContentStore.java
@@ -0,0 +1,35 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils.pubsub;
+
+import net.named_data.jndn.Face;
+import net.named_data.jndn.Name;
+
+import java.io.IOException;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+interface ContentStore<T> {
+  void put(Name name, T data);
+
+  boolean has(Name name);
+
+  T get(Name name);
+
+  void push(Face face, Name name) throws IOException;
+
+  void clear();
+}
diff --git a/src/main/java/com/intel/jndn/utils/pubsub/ForLoopPendingInterestTable.java b/src/main/java/com/intel/jndn/utils/pubsub/ForLoopPendingInterestTable.java
new file mode 100644
index 0000000..10e4084
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/pubsub/ForLoopPendingInterestTable.java
@@ -0,0 +1,51 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils.pubsub;
+
+import net.named_data.jndn.Interest;
+import net.named_data.jndn.Name;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+public class ForLoopPendingInterestTable implements PendingInterestTable {
+  Map<Name, Interest> table = new ConcurrentHashMap<>();
+
+  @Override
+  public void add(Interest interest) {
+    table.put(interest.getName(), interest);
+  }
+
+  @Override
+  public boolean has(Interest interest) {
+    // TODO must handle more complex logic (selectors)
+    return has(interest.getName());
+  }
+
+  public boolean has(Name name) {
+    return table.containsKey(name);
+  }
+
+  @Override
+  public Collection<Interest> extract(Name name) {
+    // TODO more complexity to return multiple results
+    return has(name) ? Collections.singleton(table.get(name)) : Collections.emptyList();
+  }
+}
diff --git a/src/main/java/com/intel/jndn/utils/pubsub/NdnAnnouncementService.java b/src/main/java/com/intel/jndn/utils/pubsub/NdnAnnouncementService.java
new file mode 100644
index 0000000..9679d7e
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/pubsub/NdnAnnouncementService.java
@@ -0,0 +1,163 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils.pubsub;
+
+import net.named_data.jndn.Face;
+import net.named_data.jndn.Interest;
+import net.named_data.jndn.InterestFilter;
+import net.named_data.jndn.Name;
+import net.named_data.jndn.OnInterestCallback;
+import net.named_data.jndn.OnRegisterFailed;
+import net.named_data.jndn.encoding.EncodingException;
+import net.named_data.jndn.security.SecurityException;
+
+import java.io.IOException;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import static com.intel.jndn.utils.pubsub.Cancellation.CANCELLED;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+class NdnAnnouncementService implements AnnouncementService {
+  private static final Logger LOGGER = Logger.getLogger(NdnAnnouncementService.class.getName());
+  private final Face face;
+  private final Name broadcastPrefix;
+  private final Name topicPrefix;
+  private final Name usablePrefix;
+  private final Set<Long> known = new HashSet<>();
+
+  private NdnAnnouncementService(Face face, Name broadcastPrefix, Name topicPrefix) {
+    this.face = face;
+    this.broadcastPrefix = broadcastPrefix;
+    this.topicPrefix = topicPrefix;
+    this.usablePrefix = new Name(broadcastPrefix).append(topicPrefix);
+  }
+
+  NdnAnnouncementService(Face face, Name topicPrefix) {
+    this(face, PubSubNamespace.DEFAULT_BROADCAST_PREFIX, topicPrefix);
+  }
+
+  @Override
+  public void announceEntrance(long id) throws IOException {
+    Name.Component publisherId = Name.Component.fromNumberWithMarker(id, PubSubNamespace.PUBLISHER_ID_MARKER);
+    Name.Component announcementAction = Name.Component.fromNumberWithMarker(PubSubNamespace.ANNOUNCEMENT_ENTRANCE, PubSubNamespace.ANNOUNCEMENT_ACTION_MARKER);
+    Interest interest = new Interest(new Name(broadcastPrefix).append(topicPrefix).append(publisherId).append(announcementAction));
+    face.expressInterest(interest, null);
+  }
+
+  @Override
+  public void announceExit(long id) throws IOException {
+    Name.Component publisherId = Name.Component.fromNumberWithMarker(id, PubSubNamespace.PUBLISHER_ID_MARKER);
+    Name.Component announcementAction = Name.Component.fromNumberWithMarker(PubSubNamespace.ANNOUNCEMENT_EXIT, PubSubNamespace.ANNOUNCEMENT_ACTION_MARKER);
+    Interest interest = new Interest(new Name(broadcastPrefix).append(topicPrefix).append(publisherId).append(announcementAction));
+    face.expressInterest(interest, null);
+  }
+
+  @Override
+  public Cancellation discoverExistingAnnouncements(On<Long> onFound, On<Void> onComplete, On<Exception> onError) {
+    if (onFound == null) {
+      return CANCELLED;
+    }
+
+    for (long id : known) {
+      LOGGER.info("Passing known publisher: " + id);
+      onFound.on(id);
+    }
+
+    // TODO while !backoff interval maxed out, send out interests with excludes
+    Interest interest = new Interest();
+    try {
+      long pendingInterest = face.expressInterest(interest, (i, d) -> {
+      }, (i) -> {
+      });
+      return () -> face.removePendingInterest(pendingInterest);
+    } catch (IOException e) {
+      onError.on(e);
+      return CANCELLED;
+    }
+  }
+
+  private void found(long publisherId) {
+    known.add(publisherId);
+  }
+
+  @Override
+  public Cancellation observeNewAnnouncements(On<Long> onAdded, On<Long> onRemoved, On<Exception> onError) throws RegistrationFailureException {
+    CompletableFuture<Void> future = new CompletableFuture<>();
+    OnRegistration onRegistration = new OnRegistration(future);
+    OnAnnouncement onAnnouncement = new OnAnnouncement(onAdded, onRemoved, onError);
+
+    try {
+      long registeredPrefix = face.registerPrefix(usablePrefix, onAnnouncement, (OnRegisterFailed) onRegistration, onRegistration);
+      return () -> face.removeRegisteredPrefix(registeredPrefix);
+    } catch (IOException | SecurityException e) {
+      throw new RegistrationFailureException(e);
+    }
+  }
+
+  private class OnAnnouncement implements OnInterestCallback {
+    private final On<Long> onAdded;
+    private final On<Long> onRemoved;
+    private final On<Exception> onError;
+
+    OnAnnouncement(On<Long> onAdded, On<Long> onRemoved, On<Exception> onError) {
+      this.onAdded = onAdded;
+      this.onRemoved = onRemoved;
+      this.onError = onError;
+    }
+
+    @Override
+    public void onInterest(Name name, Interest interest, Face face, long l, InterestFilter interestFilter) {
+      try {
+        long publisherId = interest.getName().get(-2).toNumberWithMarker(PubSubNamespace.PUBLISHER_ID_MARKER);
+        int announcement = (int) interest.getName().get(-1).toNumberWithMarker(PubSubNamespace.ANNOUNCEMENT_ACTION_MARKER);
+        switch (announcement) {
+          case PubSubNamespace.ANNOUNCEMENT_ENTRANCE:
+            add(publisherId);
+            break;
+          case PubSubNamespace.ANNOUNCEMENT_EXIT:
+            remove(publisherId);
+            break;
+          default:
+            LOGGER.warning("Unknown announcement action, ignoring: " + interest.toUri());
+        }
+      } catch (EncodingException e) {
+        LOGGER.log(Level.SEVERE, "Failed to decode announcement: " + interest.toUri(), e);
+        onError.on(e);
+      }
+    }
+
+    private void remove(long publisherId) {
+      LOGGER.info("Publisher leaving topic: " + publisherId);
+      known.remove(publisherId);
+      if (onRemoved != null) {
+        onRemoved.on(publisherId);
+      }
+    }
+
+    private void add(long publisherId) {
+      LOGGER.info("Publisher entering topic: " + publisherId);
+      known.add(publisherId);
+      if (onAdded != null) {
+        onAdded.on(publisherId);
+      }
+    }
+  }
+}
diff --git a/src/main/java/com/intel/jndn/utils/pubsub/NdnPublisher.java b/src/main/java/com/intel/jndn/utils/pubsub/NdnPublisher.java
new file mode 100644
index 0000000..50469ea
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/pubsub/NdnPublisher.java
@@ -0,0 +1,120 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *  
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *  
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils.pubsub;
+
+import com.intel.jndn.utils.Publisher;
+import net.named_data.jndn.Data;
+import net.named_data.jndn.Face;
+import net.named_data.jndn.Interest;
+import net.named_data.jndn.InterestFilter;
+import net.named_data.jndn.Name;
+import net.named_data.jndn.OnInterestCallback;
+import net.named_data.jndn.OnRegisterFailed;
+import net.named_data.jndn.encoding.EncodingException;
+import net.named_data.jndn.security.SecurityException;
+import net.named_data.jndn.util.Blob;
+
+import java.io.IOException;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+class NdnPublisher implements Publisher, OnInterestCallback {
+  private static final Logger LOGGER = Logger.getLogger(NdnPublisher.class.getName());
+  private final Face face; // TODO only needed in start, remove?
+  private final Name prefix; // TODO only needed in start, remove?
+  private final AnnouncementService announcementService;
+  private final PendingInterestTable pendingInterestTable;
+  private final ContentStore<Blob> contentStore;
+  private final long publisherId;
+  private volatile long latestMessageId = 0;
+  private long registrationId;
+  // TODO need pit
+
+  NdnPublisher(Face face, Name prefix, long publisherId, AnnouncementService announcementService, PendingInterestTable pendingInterestTable, ContentStore<Blob> contentStore) {
+    this.face = face;
+    this.prefix = prefix;
+    this.publisherId = publisherId;
+    this.announcementService = announcementService;
+    this.pendingInterestTable = pendingInterestTable;
+    this.contentStore = contentStore;
+  }
+
+  public void start() throws RegistrationFailureException {
+    CompletableFuture<Void> future = new CompletableFuture<>();
+    OnRegistration onRegistration = new OnRegistration(future);
+
+    try {
+      registrationId = face.registerPrefix(prefix, this, (OnRegisterFailed) onRegistration, onRegistration);
+      future.get(10, TimeUnit.SECONDS);
+      announcementService.announceEntrance(publisherId);
+    } catch (IOException | SecurityException | InterruptedException | ExecutionException | TimeoutException e) {
+      throw new RegistrationFailureException(e);
+    }
+  }
+
+  public void stop() throws IOException {
+    face.removeRegisteredPrefix(registrationId);
+    contentStore.clear();
+    announcementService.announceExit(publisherId);
+  }
+
+  // TODO should throw IOException?
+  @Override
+  public void publish(Blob message) {
+    long id = latestMessageId++; // TODO synchronize?
+    Name name = PubSubNamespace.toMessageName(prefix, publisherId, id);
+
+    contentStore.put(name, message);
+    LOGGER.log(Level.INFO, "Published message {0} to content store", id);
+
+    if(pendingInterestTable.has(new Interest(name))){
+      try {
+        contentStore.push(face, name);
+      } catch (IOException e) {
+        LOGGER.log(Level.SEVERE, "Failed to send message {0} for pending interests: {1}", new Object[]{id, name});
+      }
+    }
+  }
+
+  @Override
+  public void onInterest(Name name, Interest interest, Face face, long registrationId, InterestFilter interestFilter) {
+    try {
+      if(contentStore.has(interest.getName())){
+        contentStore.push(face, interest.getName());
+      } else {
+        pendingInterestTable.add(interest);
+      }
+
+      long id = interest.getName().get(-1).toNumberWithMarker(43);
+      Blob blob = contentStore.get(interest.getName());
+      Data data = new Data(interest.getName());
+      data.setContent(blob);
+      face.putData(data);
+      LOGGER.info("Published message " + id + " for interest: " + interest.toUri());
+    } catch (IOException e) {
+      LOGGER.log(Level.SEVERE, "Failed to publish message for interest: " + interest.toUri(), e);
+    } catch (EncodingException e) {
+      LOGGER.log(Level.SEVERE, "Failed to decode message ID for interest: " + interest.toUri(), e);
+    }
+  }
+
+}
diff --git a/src/main/java/com/intel/jndn/utils/pubsub/NdnSubscriber.java b/src/main/java/com/intel/jndn/utils/pubsub/NdnSubscriber.java
new file mode 100644
index 0000000..556b91f
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/pubsub/NdnSubscriber.java
@@ -0,0 +1,197 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils.pubsub;
+
+import com.intel.jndn.utils.Client;
+import com.intel.jndn.utils.Subscriber;
+import net.named_data.jndn.Data;
+import net.named_data.jndn.Face;
+import net.named_data.jndn.Interest;
+import net.named_data.jndn.Name;
+import net.named_data.jndn.encoding.EncodingException;
+import net.named_data.jndn.util.Blob;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.stream.Collectors;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+class NdnSubscriber implements Subscriber {
+  private static final Logger LOGGER = Logger.getLogger(NdnSubscriber.class.getName());
+  private final Face face;
+  private final Name prefix;
+  private final AnnouncementService announcementService;
+  private final Client client;
+  private final Set<Context> known = new HashSet<>();
+  private Cancellation newAnnouncementCancellation;
+  private Cancellation existingAnnouncementsCancellation;
+  private volatile boolean started = false;
+
+  NdnSubscriber(Face face, Name prefix, AnnouncementService announcementService, Client client) {
+    this.face = face;
+    this.prefix = prefix;
+    this.announcementService = announcementService;
+    this.client = client;
+  }
+
+  private void start() throws RegistrationFailureException {
+    LOGGER.log(Level.INFO, "Starting subscriber");
+
+    existingAnnouncementsCancellation = announcementService.discoverExistingAnnouncements(this::add, null, e -> stop());
+    newAnnouncementCancellation = announcementService.observeNewAnnouncements(this::add, this::remove, e -> stop());
+
+    started = true;
+  }
+
+  private void add(long publisherId) {
+    known.add(new Context(publisherId));
+  }
+
+  private void remove(long publisherId) {
+    known.remove(publisherId); // TODO incorrect
+  }
+
+  private void stop() {
+    LOGGER.log(Level.INFO, "Stopping subscriber, knows of {0} publishers: {1} ", new Object[]{known.size(), known});
+
+    if (newAnnouncementCancellation != null) {
+      newAnnouncementCancellation.cancel();
+    }
+    if (existingAnnouncementsCancellation != null) {
+      existingAnnouncementsCancellation.cancel();
+    }
+    for (Context c : known) {
+      c.cancel();
+    }
+
+    started = false;
+  }
+
+  Set<Long> knownPublishers() {
+    return known.stream().map(c -> c.publisherId).collect(Collectors.toSet());
+  }
+
+  // TODO repeated calls?
+  @Override
+  public Cancellation subscribe(On<Blob> onMessage, On<Exception> onError) {
+    if (!started) {
+      try {
+        start();
+      } catch (RegistrationFailureException e) {
+        LOGGER.log(Level.SEVERE, "Failed to start announcement service, aborting subscription", e);
+        onError.on(e);
+        return Cancellation.CANCELLED;
+      }
+    }
+
+    for (Context c : known) {
+      c.subscribe(onMessage, onError);
+    }
+
+    return this::stop;
+  }
+
+  private class Context implements Cancellation {
+    final long publisherId;
+    long messageId;
+    boolean subscribed = false;
+    On<Blob> onMessage;
+    On<Exception> onError;
+    CompletableFuture<Data> currentRequest;
+
+    Context(long publisherId) {
+      this.publisherId = publisherId;
+    }
+
+    synchronized void subscribe(On<Blob> onMessage, On<Exception> onError) {
+      this.onMessage = onMessage;
+      this.onError = onError;
+
+      if (subscribed) {
+        return;
+      }
+
+      currentRequest = client.getAsync(face, buildLatestInterest(publisherId)); // TODO backoff
+      currentRequest.handle(this::handleResponse);
+      subscribed = true;
+    }
+
+    @Override
+    public synchronized void cancel() {
+      if (currentRequest != null) {
+        currentRequest.cancel(true);
+      }
+    }
+
+    private Void handleResponse(Data data, Throwable throwable) {
+      if (throwable != null) {
+        onError.on((Exception) throwable); // TODO avoid cast?
+      } else {
+        try {
+          Response response = PubSubNamespace.toResponse(data);
+          this.messageId = response.messageId();
+          onMessage.on(response.content()); // TODO buffer and catch exceptions
+        } catch (EncodingException e) {
+          onError.on(e);
+        }
+
+        // TODO catchup and loop detection (if above fails next() is called again with same params)
+        next(this.publisherId, this.messageId);
+      }
+
+      return null;
+    }
+
+    private void next(long publisherId, long messageId) {
+      CompletableFuture<Data> nextRequest = client.getAsync(face, buildNextInterest(publisherId, messageId));
+      nextRequest.handle(this::handleResponse);
+    }
+
+    private Interest buildLatestInterest(long publisherId) {
+      Name name = PubSubNamespace.toPublisherName(prefix, publisherId);
+      Interest interest = new Interest(name); // TODO ms lifetime
+      interest.setChildSelector(Interest.CHILD_SELECTOR_RIGHT);
+      return interest;
+    }
+
+    private Interest buildNextInterest(long publisherId, long messageId) {
+      Name name = PubSubNamespace.toMessageName(prefix, publisherId, messageId + 1);
+      return new Interest(name); // TODO ms lifetime
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      if (this == o) return true;
+      if (o == null || getClass() != o.getClass()) return false;
+      Context context = (Context) o;
+      return publisherId == context.publisherId;
+    }
+
+    @Override
+    public int hashCode() {
+      return (int) (publisherId ^ (publisherId >>> 32));
+    }
+
+    @Override
+    public String toString() {
+      return "Context{" + "publisherId=" + publisherId + '}';
+    }
+  }
+}
\ No newline at end of file
diff --git a/src/main/java/com/intel/jndn/utils/pubsub/On.java b/src/main/java/com/intel/jndn/utils/pubsub/On.java
new file mode 100644
index 0000000..5bb7951
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/pubsub/On.java
@@ -0,0 +1,28 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils.pubsub;
+
+/**
+ * Generic callback API for receiving some signal T when an event is fired.
+ *
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+@FunctionalInterface
+public interface On<T> {
+  /**
+   * @param event the event object describing the occurrence
+   */
+  void on(T event);
+}
diff --git a/src/main/java/com/intel/jndn/utils/pubsub/OnRegistration.java b/src/main/java/com/intel/jndn/utils/pubsub/OnRegistration.java
new file mode 100644
index 0000000..05f631c
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/pubsub/OnRegistration.java
@@ -0,0 +1,47 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils.pubsub;
+
+import net.named_data.jndn.Name;
+import net.named_data.jndn.OnRegisterFailed;
+import net.named_data.jndn.OnRegisterSuccess;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.logging.Logger;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+class OnRegistration implements OnRegisterFailed, OnRegisterSuccess {
+  private static final Logger LOGGER = Logger.getLogger(OnRegistration.class.getName());
+  private final CompletableFuture<Void> future;
+
+  OnRegistration(CompletableFuture<Void> future) {
+    this.future = future;
+  }
+
+  @Override
+  public void onRegisterSuccess(Name name, long l) {
+    LOGGER.info("Registered prefix: " + name);
+    future.complete(null);
+  }
+
+  @Override
+  public void onRegisterFailed(Name name) {
+    String message = "Failed to register prefix: " + name;
+    LOGGER.severe(message);
+    future.completeExceptionally(new RegistrationFailureException(message));
+  }
+}
diff --git a/src/main/java/com/intel/jndn/utils/pubsub/PendingInterestTable.java b/src/main/java/com/intel/jndn/utils/pubsub/PendingInterestTable.java
new file mode 100644
index 0000000..410a565
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/pubsub/PendingInterestTable.java
@@ -0,0 +1,42 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils.pubsub;
+
+import net.named_data.jndn.Interest;
+import net.named_data.jndn.Name;
+
+import java.util.Collection;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+public interface PendingInterestTable {
+  /**
+   * @param interest the PIT entry to add
+   */
+  void add(Interest interest);
+
+  /**
+   * @param interest the incoming interest to match against
+   * @return true if the interest matches an entry already in the PIT
+   */
+  boolean has(Interest interest);
+
+  /**
+   * @param name the name to match against
+   * @return the PIT entries matching a name, removing them from the PIT
+   */
+  Collection<Interest> extract(Name name);
+}
diff --git a/src/main/java/com/intel/jndn/utils/pubsub/PubSubNamespace.java b/src/main/java/com/intel/jndn/utils/pubsub/PubSubNamespace.java
new file mode 100644
index 0000000..5df1c79
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/pubsub/PubSubNamespace.java
@@ -0,0 +1,75 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils.pubsub;
+
+import net.named_data.jndn.Data;
+import net.named_data.jndn.Name;
+import net.named_data.jndn.encoding.EncodingException;
+import net.named_data.jndn.encoding.tlv.TlvDecoder;
+import net.named_data.jndn.util.Blob;
+
+import java.util.Collections;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+class PubSubNamespace {
+  static final int MESSAGE_ID_MARKER = 42;
+  static final int PUBLISHER_ID_MARKER = 43;
+  static final int ANNOUNCEMENT_ACTION_MARKER = 44;
+
+  static final int ANNOUNCEMENT_ENTRANCE = 1;
+  static final int ANNOUNCEMENT_EXIT = 0;
+
+  static final int MESSAGE_MARKER = 100;
+  static final int MESSAGE_ATTRIBUTES_MARKER = 101;
+  static final int MESSAGE_CONTENT_MARKER = 102;
+
+  static final Name DEFAULT_BROADCAST_PREFIX = new Name("/bcast");
+
+  private PubSubNamespace() {
+    // do not instantiate this class
+  }
+
+  static Name toPublisherName(Name prefix, long publisherId) {
+    Name.Component publisherComponent = Name.Component.fromNumberWithMarker(publisherId, PubSubNamespace.PUBLISHER_ID_MARKER);
+    return new Name(prefix).append(publisherComponent);
+  }
+
+  static Name toMessageName(Name prefix, long publisherId, long messageId) {
+    Name.Component messageComponent = Name.Component.fromNumberWithMarker(messageId, PubSubNamespace.MESSAGE_ID_MARKER);
+    return toPublisherName(prefix, publisherId).append(messageComponent);
+  }
+
+  static Response toResponse(Data data) throws EncodingException {
+    long messageId = extractMessageId(data.getName());
+    TlvDecoder decoder = new TlvDecoder(data.getContent().buf());
+    int endOffset = decoder.readNestedTlvsStart(MESSAGE_MARKER);
+    Blob attributes = new Blob(decoder.readOptionalBlobTlv(MESSAGE_ATTRIBUTES_MARKER, endOffset), true);
+    Blob content = new Blob(decoder.readBlobTlv(MESSAGE_CONTENT_MARKER), true);
+    return new Response(data.getName(), messageId, Collections.singletonMap("*", attributes), content);
+  }
+
+  private static long extractMessageId(Name name) throws EncodingException {
+    for (int i = name.size(); i >= 0; i--) {
+      try {
+        return name.get(i).toNumberWithMarker(MESSAGE_ID_MARKER);
+      } catch (EncodingException e) {
+        // do nothing
+      }
+    }
+    throw new EncodingException("Failed to find message ID marker in name: " + name.toUri());
+  }
+}
diff --git a/src/main/java/com/intel/jndn/utils/pubsub/RegistrationFailureException.java b/src/main/java/com/intel/jndn/utils/pubsub/RegistrationFailureException.java
new file mode 100644
index 0000000..aa7919d
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/pubsub/RegistrationFailureException.java
@@ -0,0 +1,28 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils.pubsub;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+class RegistrationFailureException extends Exception {
+  RegistrationFailureException(String message) {
+    super(message);
+  }
+
+  public RegistrationFailureException(Exception e) {
+    super(e);
+  }
+}
diff --git a/src/main/java/com/intel/jndn/utils/pubsub/Response.java b/src/main/java/com/intel/jndn/utils/pubsub/Response.java
new file mode 100644
index 0000000..9d84f44
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/pubsub/Response.java
@@ -0,0 +1,45 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils.pubsub;
+
+import net.named_data.jndn.Name;
+import net.named_data.jndn.util.Blob;
+
+import java.util.Map;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+class Response {
+  private final Name name;
+  private final long messageId;
+  private final Map<String, Object> attributes;
+  private final Blob content;
+
+  Response(Name name, long messageId, Map<String, Object> attributes, Blob content) {
+    this.name = name;
+    this.messageId = messageId;
+    this.attributes = attributes;
+    this.content = content;
+  }
+
+  long messageId() {
+    return messageId;
+  }
+
+  Blob content() {
+    return content;
+  }
+}
diff --git a/src/main/java/com/intel/jndn/utils/pubsub/Topic.java b/src/main/java/com/intel/jndn/utils/pubsub/Topic.java
new file mode 100644
index 0000000..71c7d9f
--- /dev/null
+++ b/src/main/java/com/intel/jndn/utils/pubsub/Topic.java
@@ -0,0 +1,46 @@
+/*
+ * jndn-utils
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 3, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+
+package com.intel.jndn.utils.pubsub;
+
+import com.intel.jndn.utils.Publisher;
+import com.intel.jndn.utils.Subscriber;
+import com.intel.jndn.utils.client.impl.AdvancedClient;
+import net.named_data.jndn.Face;
+import net.named_data.jndn.Name;
+
+/**
+ * @author Andrew Brown, andrew.brown@intel.com
+ */
+public final class Topic {
+  private final Name name;
+
+  public Topic(Name name) {
+    this.name = name;
+  }
+
+  public Name name() {
+    return new Name(name);
+  }
+
+  // TODO move to PubSubFactory?
+  public Subscriber newSubscriber(Face face) {
+    return new NdnSubscriber(face, name, new NdnAnnouncementService(face, name), new AdvancedClient());
+  }
+
+  // TODO move to PubSubFactory?
+  public Publisher newPublisher(Face face) {
+    return new NdnPublisher(face, name, 23, new NdnAnnouncementService(face, name), new ForLoopPendingInterestTable(), new BlobContentStore());
+  }
+}
diff --git a/src/main/java/com/intel/jndn/utils/repository/impl/ForLoopRepository.java b/src/main/java/com/intel/jndn/utils/repository/impl/ForLoopRepository.java
index e40890d..e83e4e9 100644
--- a/src/main/java/com/intel/jndn/utils/repository/impl/ForLoopRepository.java
+++ b/src/main/java/com/intel/jndn/utils/repository/impl/ForLoopRepository.java
@@ -26,7 +26,7 @@
  * {@link net.named_data.jndn.util.MemoryContentCache} and borrows the matching
  * logic from there.
  *
- * @author Andrew Brown <andrew.brown@intel.com>
+ * @author Andrew Brown, andrew.brown@intel.com
  */
 public class ForLoopRepository implements Repository {
 
@@ -95,7 +95,7 @@
    * components (e.g. c); if the Data is not longer than the Interest, return an
    * empty component.
    */
-  private Name.Component getNextComponentAfterLastInterestComponent(Data content, Interest interest) {
+  private static Name.Component getNextComponentAfterLastInterestComponent(Data content, Interest interest) {
     if (content.getName().size() > interest.getName().size()) {
       return content.getName().get(interest.getName().size());
     } else {
@@ -132,11 +132,7 @@
    * record is fresh
    */
   private boolean hasAcceptableFreshness(Interest interest, Record record) {
-    if (!interest.getMustBeFresh()) {
-      return true;
-    } else {
-      return isFresh(record);
-    }
+    return !interest.getMustBeFresh() || isFresh(record);
   }
 
   /**
@@ -171,10 +167,10 @@
    */
   private class Record {
 
-    public final Data data;
-    public final long addedAt;
+    final Data data;
+    final long addedAt;
 
-    public Record(Data data) {
+    Record(Data data) {
       this.data = data;
       this.addedAt = System.currentTimeMillis();
     }