diff --git a/src/main/java/io/nats/client/Options.java b/src/main/java/io/nats/client/Options.java
index cd708a8f5..c4c2dcc97 100644
--- a/src/main/java/io/nats/client/Options.java
+++ b/src/main/java/io/nats/client/Options.java
@@ -1335,7 +1335,14 @@ public Builder connectionListener(ConnectionListener listener) {
             return this;
         }
 
-        // TODO: Javadoc
+        /**
+         * Set the {@link StatisticsCollector StatisticsCollector} to collect connection metrics.
+         * <p>
+         * If not set, then a default implementation will be used.
+         *
+         * @param collector the new StatisticsCollector for this connection.
+         * @return the Builder for chaining
+         */
         public Builder statisticsCollector(StatisticsCollector collector) {
             this.statisticsCollector = collector;
             return this;
@@ -1706,6 +1713,9 @@ public ConnectionListener getConnectionListener() {
         return this.connectionListener;
     }
 
+    /**
+     * @return the statistics collector, or null, see {@link Builder#statisticsCollector(StatisticsCollector) statisticsCollector()} in the builder doc
+     */
     public StatisticsCollector getStatisticsCollector() {
         return this.statisticsCollector;
     }
diff --git a/src/main/java/io/nats/client/Statistics.java b/src/main/java/io/nats/client/Statistics.java
index 8e9d014cb..73957e9cc 100644
--- a/src/main/java/io/nats/client/Statistics.java
+++ b/src/main/java/io/nats/client/Statistics.java
@@ -21,8 +21,9 @@
  */
 public interface Statistics {
 
-    // TODO: Javadoc -- methods and indicate which stats are advanced stats
-
+    /**
+     * @return the total number of pings that have been sent from this connection.
+     */
     long getPings();
 
     /**
@@ -35,14 +36,29 @@ public interface Statistics {
      */
     long getDroppedCount();
 
+    /**
+     * @return the total number of op +OKs received by this connection.
+     */
     long getOKs();
 
+    /**
+     * @return the total number of op -ERRs received by this connection.
+     */
     long getErrs();
 
+    /**
+     * @return the total number of exceptions seen by this connection.
+     */
     long getExceptions();
 
+    /**
+     * @return the total number of requests sent by this connection.
+     */
     long getRequestsSent();
 
+    /**
+     * @return the total number of replies received by this connection.
+     */
     long getRepliesReceived();
 
     /**
@@ -75,11 +91,17 @@ public interface Statistics {
     long getInBytes();
 
     /**
-     * @return the total number of message bytes that have gone out of to this connection.
+     * @return the total number of message bytes that have gone out of this connection.
      */
     long getOutBytes();
 
+    /**
+     * @return the total number of outgoing message flushes by this connection.
+     */
     long getFlushCounter();
 
+    /**
+     * @return the count of outstanding of requests from this connection.
+     */
     long getOutstandingRequests();
 }
diff --git a/src/main/java/io/nats/client/StatisticsCollector.java b/src/main/java/io/nats/client/StatisticsCollector.java
index 736a2e9f2..b7de6514d 100644
--- a/src/main/java/io/nats/client/StatisticsCollector.java
+++ b/src/main/java/io/nats/client/StatisticsCollector.java
@@ -13,13 +13,22 @@
 
 package io.nats.client;
 
-// TODO: Javadoc -- class and methods and indicate which stats are advanced stats
+/**
+ * A collector for connection metrics.
+ * <p>
+ * Information about key metrics is incremented on this collector by the connection.
+ * <p>
+ * See {@link Statistics} for accessing the collected metrics.
+ */
 public interface StatisticsCollector extends Statistics {
     /**
      * Sets whether advanced stats are/should be tracked.
      */
     void setAdvancedTracking(boolean trackAdvanced);
 
+    /**
+     * Increments the total number of pings that have been sent from this connection.
+     */
     void incrementPingCount();
 
     /**
@@ -32,14 +41,29 @@ public interface StatisticsCollector extends Statistics {
      */
     void incrementDroppedCount();
 
+    /**
+     * Increments the total number of op +OKs received by this connection.
+     */
     void incrementOkCount();
 
+    /**
+     * Increments the total number of op -ERRs received by this connection.
+     */
     void incrementErrCount();
 
+    /**
+     * Increments the total number of exceptions seen by this connection.
+     */
     void incrementExceptionCount();
 
+    /**
+     * Increments the total number of requests sent by this connection.
+     */
     void incrementRequestsSent();
 
+    /**
+     * Increments the total number of replies received by this connection.
+     */
     void incrementRepliesReceived();
 
     /**
@@ -66,14 +90,29 @@ public interface StatisticsCollector extends Statistics {
      */
     void incrementOutMsgs();
 
+    /**
+     * Increment the total number of message bytes that have come in to this connection.
+     */
     void incrementInBytes(long bytes);
 
+    /**
+     * Increment the total number of message bytes that have gone out of this connection.
+     */
     void incrementOutBytes(long bytes);
 
+    /**
+     * Increment the total number of outgoing message flushes by this connection.
+     */
     void incrementFlushCounter();
 
+    /**
+     * Increments the count of outstanding of requests from this connection.
+     */
     void incrementOutstandingRequests();
 
+    /**
+     * Decrements the count of outstanding of requests from this connection.
+     */
     void decrementOutstandingRequests();
 
     /**