diff --git a/src/main/java/net/onrc/onos/apps/bgproute/BgpRoute.java b/src/main/java/net/onrc/onos/apps/bgproute/BgpRoute.java
index 3c588f2..91ac959 100644
--- a/src/main/java/net/onrc/onos/apps/bgproute/BgpRoute.java
+++ b/src/main/java/net/onrc/onos/apps/bgproute/BgpRoute.java
@@ -91,25 +91,30 @@
     private String routerId;
     private String configFilename = "config.json";
 
-    //We need to identify our flows somehow. But like it says in LearningSwitch.java,
-    //the controller/OS should hand out cookie IDs to prevent conflicts.
-    private static final long APP_COOKIE = 0xa0000000000000L;
-    //Cookie for flows that do L2 forwarding within SDN domain to egress routers
-    private static final long L2_FWD_COOKIE = APP_COOKIE + 1;
-    //Cookie for flows in ingress switches that rewrite the MAC address
-    private static final long MAC_RW_COOKIE = APP_COOKIE + 2;
-    //Cookie for flows that setup BGP paths
-    private static final long BGP_COOKIE = APP_COOKIE + 3;
-    //Forwarding uses priority 0, and the mac rewrite entries in ingress switches
-    //need to be higher priority than this otherwise the rewrite may not get done
-    private static final short SDNIP_PRIORITY = 10;
     private static final short ARP_PRIORITY = 20;
+    
+    // The fields below are unused after the move to FlowManager.
+    // Remove them if no longer needed.
+    /*
+    // We need to identify our flows somehow, in lieu of an OS-wide mechanism
+    // to hand out cookie IDs to prevent conflicts.
+    private static final long APP_COOKIE = 0xa0000000000000L;
+    // Cookie for flows that do L2 forwarding within SDN domain to egress routers
+    private static final long L2_FWD_COOKIE = APP_COOKIE + 1;
+    // Cookie for flows in ingress switches that rewrite the MAC address
+    private static final long MAC_RW_COOKIE = APP_COOKIE + 2;
+    // Cookie for flows that setup BGP paths
+    private static final long BGP_COOKIE = APP_COOKIE + 3;
+    // Forwarding uses priority 0, and the mac rewrite entries in ingress switches
+    // need to be higher priority than this otherwise the rewrite may not get done
+    private static final short SDNIP_PRIORITY = 10;
+    */
 
     private static final short BGP_PORT = 179;
 
-    private static final int TOPO_DETECTION_WAIT = 2; //seconds
+    private static final int TOPO_DETECTION_WAIT = 2; // seconds
 
-    //Configuration stuff
+    // Configuration stuff
     private List<String> switches;
     private Map<String, Interface> interfaces;
     private Map<InetAddress, BgpPeer> bgpPeers;
@@ -117,12 +122,12 @@
     private MACAddress bgpdMacAddress;
     private short vlan;
 
-    //True when all switches have connected
+    // True when all switches have connected
     private volatile boolean switchesConnected = false;
-    //True when we have a full mesh of shortest paths between gateways
+    // True when we have a full mesh of shortest paths between gateways
     private volatile boolean topologyReady = false;
 
-    private ArrayList<LDUpdate> linkUpdates;
+    private List<LDUpdate> linkUpdates;
     private SingletonTask topologyChangeDetectorTask;
 
     private SetMultimap<InetAddress, RibUpdate> prefixesWaitingOnArp;
@@ -168,12 +173,12 @@
 
             if (!topologyReady) {
                 if (linkUpdates.isEmpty()) {
-                    //All updates have been seen in network map.
-                    //We can check if topology is ready
+                    // All updates have been seen in network map.
+                    // We can check if topology is ready
                     log.debug("No known changes outstanding. Checking topology now");
                     checkStatus();
                 } else {
-                    //We know of some link updates that haven't propagated to the database yet
+                    // We know of some link updates that haven't propagated to the database yet
                     log.debug("Some changes not found in network map - {} links missing", linkUpdates.size());
                     topologyChangeDetectorTask.reschedule(TOPO_DETECTION_WAIT, TimeUnit.SECONDS);
                 }
@@ -215,7 +220,7 @@
             System.exit(1);
         }
 
-        //Populate the interface Patricia Trie
+        // Populate the interface Patricia Trie
         for (Interface intf : interfaces.values()) {
             Prefix prefix = new Prefix(intf.getIpAddress().getAddress(), intf.getPrefixLength());
             interfacePtrie.put(prefix, intf);
@@ -282,7 +287,7 @@
         bgpUpdatesExecutor = Executors.newSingleThreadExecutor(
                 new ThreadFactoryBuilder().setNameFormat("bgp-updates-%d").build());
 
-        //Read in config values
+        // Read in config values
         bgpdRestIp = context.getConfigParams(this).get("BgpdRestIp");
         if (bgpdRestIp == null) {
             log.error("BgpdRestIp property not found in config file");
@@ -313,7 +318,7 @@
         restApi.addRestletRoutable(new BgpRouteWebRoutable());
         floodlightProvider.addOFSwitchListener(this);
 
-        //Retrieve the RIB from BGPd during startup
+        // Retrieve the RIB from BGPd during startup
         retrieveRib();
     }
 
@@ -341,25 +346,25 @@
         String url = "http://" + bgpdRestIp + "/wm/bgp/" + routerId;
         String response = RestClient.get(url);
 
-        if (response.equals("")) {
+        if ("".equals(response)) {
             return;
         }
 
         response = response.replaceAll("\"", "'");
         JSONObject jsonObj = (JSONObject) JSONSerializer.toJSON(response);
-        JSONArray ribJsonArray = jsonObj.getJSONArray("rib");
+        JSONArray ribArray = jsonObj.getJSONArray("rib");
         String routerId = jsonObj.getString("router-id");
 
-        int size = ribJsonArray.size();
+        int size = ribArray.size();
 
         log.info("Retrived RIB of {} entries from BGPd", size);
 
         for (int j = 0; j < size; j++) {
-            JSONObject secondJsonObject = ribJsonArray.getJSONObject(j);
-            String prefix = secondJsonObject.getString("prefix");
-            String nexthop = secondJsonObject.getString("nexthop");
+            JSONObject ribEntry = ribArray.getJSONObject(j);
+            String prefix = ribEntry.getString("prefix");
+            String nexthop = ribEntry.getString("nexthop");
 
-            //insert each rib entry into the local rib;
+            // Insert each rib entry into the local rib
             String[] substring = prefix.split("/");
             String prefix1 = substring[0];
             String mask1 = substring[1];
@@ -395,29 +400,31 @@
         }
     }
 
-    public synchronized void processRibAdd(RibUpdate update) {
-        Prefix prefix = update.getPrefix();
-
-        log.debug("Processing prefix add {}", prefix);
-
-        RibEntry rib = ptree.put(prefix, update.getRibEntry());
-
-        if (rib != null && !rib.equals(update.getRibEntry())) {
-            //There was an existing nexthop for this prefix. This update supersedes that,
-            //so we need to remove the old flows for this prefix from the switches
-            _processDeletePrefix(prefix, rib);
+    public void processRibAdd(RibUpdate update) {
+        synchronized (this) {
+            Prefix prefix = update.getPrefix();
+    
+            log.debug("Processing prefix add {}", prefix);
+    
+            RibEntry rib = ptree.put(prefix, update.getRibEntry());
+    
+            if (rib != null && !rib.equals(update.getRibEntry())) {
+                // There was an existing nexthop for this prefix. This update supersedes that,
+                // so we need to remove the old flows for this prefix from the switches
+                _processDeletePrefix(prefix, rib);
+            }
+    
+            if (update.getRibEntry().getNextHop().equals(
+                    InetAddresses.forString("0.0.0.0"))) {
+                // Route originated by SDN domain
+                // We don't handle these at the moment
+                log.debug("Own route {} to {}", prefix,
+                        update.getRibEntry().getNextHop().getHostAddress());
+                return;
+            }
+    
+            _processRibAdd(update);
         }
-
-        if (update.getRibEntry().getNextHop().equals(
-                InetAddresses.forString("0.0.0.0"))) {
-            //Route originated by SDN domain
-            //We don't handle these at the moment
-            log.debug("Own route {} to {}", prefix,
-                    update.getRibEntry().getNextHop().getHostAddress());
-            return;
-        }
-
-        _processRibAdd(update);
     }
 
     private void _processRibAdd(RibUpdate update) {
@@ -578,16 +585,18 @@
         }
     }
 
-    public synchronized void processRibDelete(RibUpdate update) {
-        Prefix prefix = update.getPrefix();
-
-        if (ptree.remove(prefix, update.getRibEntry())) {
-            /*
-             * Only delete flows if an entry was actually removed from the trie.
-             * If no entry was removed, the <prefix, nexthop> wasn't there so
-             * it's probably already been removed and we don't need to do anything
-             */
-            _processDeletePrefix(prefix, update.getRibEntry());
+    public void processRibDelete(RibUpdate update) {
+        synchronized (this) {
+            Prefix prefix = update.getPrefix();
+    
+            if (ptree.remove(prefix, update.getRibEntry())) {
+                /*
+                 * Only delete flows if an entry was actually removed from the trie.
+                 * If no entry was removed, the <prefix, nexthop> wasn't there so
+                 * it's probably already been removed and we don't need to do anything
+                 */
+                _processDeletePrefix(prefix, update.getRibEntry());
+            }
         }
     }
 
@@ -779,7 +788,7 @@
     }
 
     /**
-     * Pre-actively install all BGP traffic paths from BGP host attachment point
+     * Proactively install all BGP traffic paths from BGP host attachment point
      * in SDN network to all the virtual gateways to BGP peers in other networks
      */
     private void setupBgpPaths() {
@@ -886,7 +895,7 @@
             reverseDataPath.setSrcPort(reverseSrcPort);
             flowPath.setDataPath(reverseDataPath);
 
-            // reverse the dst IP and src IP addresses
+            // Reverse the dst IP and src IP addresses
             flowEntryMatch.enableDstIPv4Net(srcIPv4Net);
             flowEntryMatch.enableSrcIPv4Net(dstIPv4Net);
             flowPath.setFlowEntryMatch(flowEntryMatch);
@@ -931,7 +940,7 @@
             /**
              * ICMP paths between BGPd and its peers
              */
-            //match ICMP protocol BGP <- Peer
+            // match ICMP protocol BGP <- Peer
             flowPath.setFlowId(new FlowId());
 
             flowEntryMatch.enableIpProto(IPv4.PROTOCOL_ICMP);
@@ -957,7 +966,7 @@
             }
             */
 
-            //match ICMP protocol BGP -> Peer
+            // match ICMP protocol BGP -> Peer
             flowPath.setFlowId(new FlowId());
 
             flowEntryMatch.enableDstIPv4Net(dstIPv4Net);
@@ -1000,11 +1009,11 @@
                 log.debug("Pushing path to {} at {} on {}", new Object[]{
                         path.getDstIpAddress().getHostAddress(), macAddress,
                         path.getDstInterface().getSwitchPort()});
-                //These paths should always be to BGP peers. Paths to non-peers are
-                //handled once the first prefix is ready to push
+                // These paths should always be to BGP peers. Paths to non-peers are
+                // handled once the first prefix is ready to push
                 if (pushedPaths.containsKey(path.getDstIpAddress())) {
-                    //A path already got pushed to this endpoint while we were waiting
-                    //for ARP. We'll copy over the permanent attribute if it is set on this path.
+                    // A path already got pushed to this endpoint while we were waiting
+                    // for ARP. We'll copy over the permanent attribute if it is set on this path.
                     if (path.isPermanent()) {
                         pushedPaths.get(path.getDstIpAddress()).setPermanent();
                     }
@@ -1017,16 +1026,16 @@
             Set<RibUpdate> prefixesToPush = prefixesWaitingOnArp.removeAll(ipAddress);
 
             for (RibUpdate update : prefixesToPush) {
-                //These will always be adds
+                // These will always be adds
 
                 RibEntry rib = ptree.lookup(update.getPrefix());
                 if (rib != null && rib.equals(update.getRibEntry())) {
                     log.debug("Pushing prefix {} next hop {}", update.getPrefix(),
                             rib.getNextHop().getHostAddress());
-                    //We only push prefix flows if the prefix is still in the ptree
-                    //and the next hop is the same as our update. The prefix could
-                    //have been removed while we were waiting for the ARP, or the
-                    //next hop could have changed.
+                    // We only push prefix flows if the prefix is still in the ptree
+                    // and the next hop is the same as our update. The prefix could
+                    // have been removed while we were waiting for the ARP, or the
+                    // next hop could have changed.
                     _processRibAdd(update);
                 } else {
                     log.debug("Received ARP response, but {},{} is no longer in ptree",
@@ -1036,7 +1045,7 @@
         }
     }
 
-    //TODO wait the priority module of the flow Manager
+    // TODO wait the priority module of the flow Manager
     private void setupArpFlows() {
         OFMatch match = new OFMatch();
         match.setDataLayerType(Ethernet.TYPE_ARP);
@@ -1065,11 +1074,11 @@
         }
     }
 
-    //TODO need update, waiting for the priority feature from flow Manager
+    // TODO need update, waiting for the priority feature from flow Manager
     private void setupDefaultDropFlows() {
         OFFlowMod fm = new OFFlowMod();
         fm.setMatch(new OFMatch());
-        fm.setActions(new ArrayList<OFAction>()); //No action means drop
+        fm.setActions(new ArrayList<OFAction>()); // No action means drop
 
         fm.setIdleTimeout((short) 0)
                 .setHardTimeout((short) 0)
@@ -1148,12 +1157,13 @@
         });
     }
 
-    // Before inserting the paths for BGP traffic, we should check
-    // whether all the switches in the configure file are discovered by onos.
+    // Before inserting the paths for BGP traffic, we should check whether
+    // all the switches in the configuration file are discovered by ONOS
     private void checkSwitchesConnected() {
+        // TODO: Fix the code below after topoSwitchSerice was removed
+        /*
         for (String dpid : switches) {
-            // TODO: Fix the code below after topoSwitchSerice was removed
-            /*
+            
             Iterator<ISwitchObject> activeSwitches = topoSwitchService.
                     getActiveSwitches().iterator();
             while(activeSwitches.hasNext())
@@ -1167,13 +1177,13 @@
                     return;
                 }
             }
-            */
+            
         }
         switchesConnected = true;
+        */
     }
 
-    //Actually we only need to go half way round to verify full mesh connectivity
-    //(n^2)/2
+    // Actually we only need to go half way round to verify full mesh connectivity
     private void checkTopologyReady() {
         for (Interface dstInterface : interfaces.values()) {
             for (Interface srcInterface : interfaces.values()) {
@@ -1323,10 +1333,12 @@
 
     @Override
     public void removedSwitch(IOFSwitch sw) {
+        // Not used
     }
 
     @Override
     public void switchPortChanged(Long switchId) {
+        // Not used
     }
 
     @Override
diff --git a/src/main/java/net/onrc/onos/apps/bgproute/BgpRouteResource.java b/src/main/java/net/onrc/onos/apps/bgproute/BgpRouteResource.java
index 2ac3414..5c14db1 100644
--- a/src/main/java/net/onrc/onos/apps/bgproute/BgpRouteResource.java
+++ b/src/main/java/net/onrc/onos/apps/bgproute/BgpRouteResource.java
@@ -138,7 +138,8 @@
         log.debug("sysuptime: {}", strSysuptime);
         log.debug("sequence: {}", strSequence);
 
-        String reply = "";
+        //String reply = "";
+        StringBuilder replyStringBuilder = new StringBuilder(80);
 
         if (capability == null) {
             // this is a prefix delete
@@ -149,11 +150,11 @@
                 sysUpTime = Long.parseLong(strSysuptime);
                 sequenceNum = Long.parseLong(strSequence);
             } catch (NumberFormatException e) {
-                reply = "[DELE: mask format is wrong]";
+                String reply = "[DELE: mask format is wrong]";
                 log.info(reply);
                 return reply + "\n";
             } catch (IllegalArgumentException e1) {
-                reply = "[DELE: prefix format is wrong]";
+                String reply = "[DELE: prefix format is wrong]";
                 log.info(reply);
                 return reply + "\n";
             }
@@ -162,18 +163,25 @@
 
             bgpRoute.newRibUpdate(new RibUpdate(Operation.DELETE, p, r));
 
-            reply = reply + "[DELE: " + prefix + "/" + mask + ":" + nextHop
-                    + "]";
+            replyStringBuilder.append("[DELE: ")
+                .append(prefix)
+                .append('/')
+                .append(mask)
+                .append(':')
+                .append(nextHop)
+                .append(']');
         } else {
             // clear the local rib: Ptree
             bgpRoute.clearPtree();
-            reply = "[DELE-capability: " + capability
-                    + "; The local RibEntry is cleared!]\n";
+            replyStringBuilder.append("[DELE-capability: ")
+                    .append(capability)
+                    .append("; The local RibEntry is cleared!]\n");
 
             // to store the number in the top node of the Ptree
         }
 
-        log.info(reply);
-        return reply + "\n";
+        log.info(replyStringBuilder.toString());
+        replyStringBuilder.append('\n');
+        return replyStringBuilder.toString();
     }
 }
diff --git a/src/main/java/net/onrc/onos/apps/bgproute/BgpRouteResourceSynch.java b/src/main/java/net/onrc/onos/apps/bgproute/BgpRouteResourceSynch.java
index b38a400..13434dc 100644
--- a/src/main/java/net/onrc/onos/apps/bgproute/BgpRouteResourceSynch.java
+++ b/src/main/java/net/onrc/onos/apps/bgproute/BgpRouteResourceSynch.java
@@ -44,17 +44,23 @@
         String mask = (String) getRequestAttributes().get("mask");
         String nextHop = (String) getRequestAttributes().get("nexthop");
 
-        String reply = "";
+        StringBuilder reply = new StringBuilder();
 
         String bgpdRestIp = bgpRoute.getBGPdRestIp();
 
         RestClient.delete("http://" + bgpdRestIp + "/wm/bgp/" + routerId + "/" + prefix + "/"
                 + mask + "/" + nextHop);
 
-        reply = reply + "[DELE: " + prefix + "/" + mask + ":" + nextHop + "/synch]";
+        reply.append("[DELE: ")
+             .append(prefix)
+             .append('/')
+             .append(mask)
+             .append(':')
+             .append(nextHop)
+             .append("/synch]");
 
-        log.info(reply);
+        log.info(reply.toString());
 
-        return reply + "\n";
+        return reply.append("\n").toString();
     }
 }
diff --git a/src/main/java/net/onrc/onos/apps/bgproute/FlowCache.java b/src/main/java/net/onrc/onos/apps/bgproute/FlowCache.java
index 145224b..5341e1d 100644
--- a/src/main/java/net/onrc/onos/apps/bgproute/FlowCache.java
+++ b/src/main/java/net/onrc/onos/apps/bgproute/FlowCache.java
@@ -21,11 +21,12 @@
 public class FlowCache {
     private final static Logger log = LoggerFactory.getLogger(FlowCache.class);
 
-    private IFloodlightProviderService floodlightProvider;
+    private final IFloodlightProviderService floodlightProvider;
 
-    private Map<Long, List<OFFlowMod>> flowCache;
+    private final Map<Long, List<OFFlowMod>> flowCacheMap;
 
-    private Comparator<OFFlowMod> cookieComparator = new Comparator<OFFlowMod>() {
+    private final Comparator<OFFlowMod> cookieComparator = 
+            new Comparator<OFFlowMod>() {
         @Override
         public int compare(OFFlowMod fm1, OFFlowMod fm2) {
             long difference = fm2.getCookie() - fm1.getCookie();
@@ -43,114 +44,121 @@
     public FlowCache(IFloodlightProviderService floodlightProvider) {
         this.floodlightProvider = floodlightProvider;
 
-        flowCache = new HashMap<Long, List<OFFlowMod>>();
+        flowCacheMap = new HashMap<Long, List<OFFlowMod>>();
     }
 
-    public synchronized void write(long dpid, OFFlowMod flowMod) {
-        List<OFFlowMod> flowModList = new ArrayList<OFFlowMod>(1);
-        flowModList.add(flowMod);
-        write(dpid, flowModList);
+    public void write(long dpid, OFFlowMod flowMod) {
+        synchronized (this) {
+            List<OFFlowMod> flowModList = new ArrayList<OFFlowMod>(1);
+            flowModList.add(flowMod);
+            write(dpid, flowModList);
+        }
     }
 
-    public synchronized void write(long dpid, List<OFFlowMod> flowMods) {
-        ensureCacheForSwitch(dpid);
-
-        List<OFFlowMod> clones = new ArrayList<OFFlowMod>(flowMods.size());
-
-        //Somehow the OFFlowMods we get passed in will change later on.
-        //No idea how this happens, but we can just clone to prevent problems
-        try {
-            for (OFFlowMod fm : flowMods) {
-                clones.add(fm.clone());
+    public void write(long dpid, List<OFFlowMod> flowMods) {
+        synchronized (this) {
+            ensureCacheForSwitch(dpid);
+    
+            List<OFFlowMod> clones = new ArrayList<OFFlowMod>(flowMods.size());
+    
+            // Somehow the OFFlowMods we get passed in will change later on.
+            // No idea how this happens, but we can just clone to prevent problems
+            try {
+                for (OFFlowMod fm : flowMods) {
+                    clones.add(fm.clone());
+                }
+            } catch (CloneNotSupportedException e) {
+                log.debug("Clone exception", e);
             }
-        } catch (CloneNotSupportedException e) {
-            log.debug("Clone exception", e);
-        }
-
-        flowCache.get(dpid).addAll(clones);
-
-        IOFSwitch sw = floodlightProvider.getSwitches().get(dpid);
-
-        if (sw == null) {
-            log.debug("Switch not found when writing flow mods");
-            return;
-        }
-
-        List<OFMessage> msgList = new ArrayList<OFMessage>(clones.size());
-        msgList.addAll(clones);
-
-        try {
-            sw.write(msgList, null);
-        } catch (IOException e) {
-            log.error("Error writing to switch", e);
-        }
-
-
-    }
-
-    public synchronized void delete(long dpid, OFFlowMod flowMod) {
-        List<OFFlowMod> flowModList = new ArrayList<OFFlowMod>(1);
-        flowModList.add(flowMod);
-        delete(dpid, flowModList);
-    }
-
-    public synchronized void delete(long dpid, List<OFFlowMod> flowMods) {
-        ensureCacheForSwitch(dpid);
-
-        //Remove the flow mods from the cache first before we alter them
-        flowCache.get(dpid).removeAll(flowMods);
-
-        //Alter the original flow mods to make them delete flow mods
-        for (OFFlowMod fm : flowMods) {
-            fm.setCommand(OFFlowMod.OFPFC_DELETE_STRICT)
-                    .setOutPort(OFPort.OFPP_NONE)
-                    .setLengthU(OFFlowMod.MINIMUM_LENGTH);
-
-            fm.getActions().clear();
-        }
-
-        IOFSwitch sw = floodlightProvider.getSwitches().get(dpid);
-        if (sw == null) {
-            log.debug("Switch not found when writing flow mods");
-            return;
-        }
-
-        List<OFMessage> msgList = new ArrayList<OFMessage>(flowMods.size());
-        msgList.addAll(flowMods);
-
-        try {
-            sw.write(msgList, null);
-        } catch (IOException e) {
-            log.error("Error writing to switch", e);
+    
+            flowCacheMap.get(dpid).addAll(clones);
+    
+            IOFSwitch sw = floodlightProvider.getSwitches().get(dpid);
+    
+            if (sw == null) {
+                log.debug("Switch not found when writing flow mods");
+                return;
+            }
+    
+            List<OFMessage> msgList = new ArrayList<OFMessage>(clones.size());
+            msgList.addAll(clones);
+    
+            try {
+                sw.write(msgList, null);
+            } catch (IOException e) {
+                log.error("Error writing to switch", e);
+            }
         }
     }
 
-    //TODO can the Prontos handle being sent all flow mods in one message?
-    public synchronized void switchConnected(IOFSwitch sw) {
-        log.debug("Switch connected: {}", sw);
+    public void delete(long dpid, OFFlowMod flowMod) {
+        synchronized (this) {
+            List<OFFlowMod> flowModList = new ArrayList<OFFlowMod>(1);
+            flowModList.add(flowMod);
+            delete(dpid, flowModList);
+        }
+    }
 
-        ensureCacheForSwitch(sw.getId());
+    public void delete(long dpid, List<OFFlowMod> flowMods) {
+        synchronized (this) {
+            ensureCacheForSwitch(dpid);
+    
+            // Remove the flow mods from the cache first before we alter them
+            flowCacheMap.get(dpid).removeAll(flowMods);
+    
+            // Alter the original flow mods to make them delete flow mods
+            for (OFFlowMod fm : flowMods) {
+                fm.setCommand(OFFlowMod.OFPFC_DELETE_STRICT)
+                        .setOutPort(OFPort.OFPP_NONE)
+                        .setLengthU(OFFlowMod.MINIMUM_LENGTH);
+    
+                fm.getActions().clear();
+            }
+    
+            IOFSwitch sw = floodlightProvider.getSwitches().get(dpid);
+            if (sw == null) {
+                log.debug("Switch not found when writing flow mods");
+                return;
+            }
+    
+            List<OFMessage> msgList = new ArrayList<OFMessage>(flowMods.size());
+            msgList.addAll(flowMods);
+    
+            try {
+                sw.write(msgList, null);
+            } catch (IOException e) {
+                log.error("Error writing to switch", e);
+            }
+        }
+    }
 
-        List<OFFlowMod> flowMods = flowCache.get(sw.getId());
-
-        Collections.sort(flowMods, cookieComparator);
-
-        sw.clearAllFlowMods();
-
-        List<OFMessage> messages = new ArrayList<OFMessage>(flowMods.size());
-        messages.addAll(flowMods);
-
-        try {
-            sw.write(messages, null);
-        } catch (IOException e) {
-            log.error("Failure writing flow mods to switch {}",
-                    HexString.toHexString(sw.getId()));
+    public void switchConnected(IOFSwitch sw) {
+        synchronized (this) {
+            log.debug("Switch connected: {}", sw);
+    
+            ensureCacheForSwitch(sw.getId());
+    
+            List<OFFlowMod> flowMods = flowCacheMap.get(sw.getId());
+    
+            Collections.sort(flowMods, cookieComparator);
+    
+            sw.clearAllFlowMods();
+    
+            List<OFMessage> messages = new ArrayList<OFMessage>(flowMods.size());
+            messages.addAll(flowMods);
+    
+            try {
+                sw.write(messages, null);
+            } catch (IOException e) {
+                log.error("Failure writing flow mods to switch {}",
+                        HexString.toHexString(sw.getId()));
+            }
         }
     }
 
     private void ensureCacheForSwitch(long dpid) {
-        if (!flowCache.containsKey(dpid)) {
-            flowCache.put(dpid, new ArrayList<OFFlowMod>());
+        if (!flowCacheMap.containsKey(dpid)) {
+            flowCacheMap.put(dpid, new ArrayList<OFFlowMod>());
         }
     }
 }
diff --git a/src/main/java/net/onrc/onos/apps/bgproute/Prefix.java b/src/main/java/net/onrc/onos/apps/bgproute/Prefix.java
index 74b6ad9..9ba046c 100644
--- a/src/main/java/net/onrc/onos/apps/bgproute/Prefix.java
+++ b/src/main/java/net/onrc/onos/apps/bgproute/Prefix.java
@@ -128,7 +128,7 @@
                     return result.toString();
                 }
             }
-            result.append(" ");
+            result.append(' ');
         }
         return result.substring(0, result.length() - 1);
     }