Expose String Attributes to JSON

Change-Id: Ibc6de214cb8cedb7c262336adcfb283637fe9dc5
diff --git a/src/main/java/net/onrc/onos/core/topology/web/serializers/PortSerializer.java b/src/main/java/net/onrc/onos/core/topology/web/serializers/PortSerializer.java
index a0d7385..69d710e 100644
--- a/src/main/java/net/onrc/onos/core/topology/web/serializers/PortSerializer.java
+++ b/src/main/java/net/onrc/onos/core/topology/web/serializers/PortSerializer.java
@@ -1,6 +1,7 @@
 package net.onrc.onos.core.topology.web.serializers;
 
 import java.io.IOException;
+import java.util.Map.Entry;
 
 import net.onrc.onos.core.topology.Port;
 
@@ -35,6 +36,11 @@
         jsonGenerator.writeNumberField("portNumber",
                                        (0xffff & port.getNumber().value()));
         jsonGenerator.writeStringField("desc", port.getDescription());
+        jsonGenerator.writeObjectFieldStart("stringAttributes");
+        for (Entry<String, String> entry : port.getAllStringAttributes().entrySet()) {
+            jsonGenerator.writeStringField(entry.getKey(), entry.getValue());
+        }
+        jsonGenerator.writeEndObject(); // stringAttributes
         jsonGenerator.writeEndObject();
     }
 }