Merge into master from pull request #109:

Fix a null pointer exception in DeviceManagerImpl [Bug #436: Resolved]. (https://github.com/floodlight/floodlight/pull/109)

build.xml

@@ -111,7 +111,7 @@
 	       debug="true" 
 	       srcdir="${source}:${packetstreamer-gen}"
 	       destdir="${build}">
-	</javac>
+        </javac>
     </target>
 
     <target name="compile-tests" depends="compile-test"/>

src/main/java/net/floodlightcontroller/devicemanager/internal/DeviceManagerImpl.java

@@ -621,6 +621,7 @@ public class DeviceManagerImpl implements IDeviceManagerService, IOFMessageListe
         protected boolean inSamePortChannel(SwitchPortTuple swPort1,
                                         SwitchPortTuple swPort2) {
             IOFSwitch sw = swPort1.getSw();
+            if (sw == null) return false;
             String portName = sw.getPort(swPort1.getPort()).getName();
             String key = sw.getStringId() + portName;
             String portChannel1 = portChannelMap.get(key);
@@ -628,6 +629,7 @@ public class DeviceManagerImpl implements IDeviceManagerService, IOFMessageListe
                 return false;
 
             sw = swPort2.getSw();
+            if (sw == null) return false;
             portName = sw.getPort(swPort2.getPort()).getName();
             key = sw.getStringId() + portName;
             String portChannel2 = portChannelMap.get(key);

src/main/java/net/floodlightcontroller/topology/NodePortTuple.java

 package net.floodlightcontroller.topology;
 
+import net.floodlightcontroller.linkdiscovery.SwitchPortTuple;
+
 import org.openflow.util.HexString;
 
+/**
+ * A NodePortTuple is similar to a SwitchPortTuple
+ * but it only stores IDs instead of references
+ * to the actual objects.
+ * @author srini
+ */
 public class NodePortTuple {
-    protected long nodeId;
-    protected short portId;
+    protected long nodeId; // switch DPID
+    protected short portId; // switch port id
 
+    /**
+     * Creates a NodePortTuple
+     * @param nodeId The DPID of the switch
+     * @param portId The port of the switch
+     */
     public NodePortTuple(long nodeId, short portId) {
         this.nodeId = nodeId;
         this.portId = portId;
     }
+    
+    /**
+     * Creates a NodePortTuple from the same information
+     * in a SwitchPortTuple
+     * @param swt
+     */
+    public NodePortTuple(SwitchPortTuple swt) {
+        if (swt.getSw() != null)
+            this.nodeId = swt.getSw().getId();
+        else
+            this.nodeId = 0;
+        this.portId = swt.getPort();
+    }
 
     public long getNodeId() {
         return nodeId;