Fix links REST API.

src/main/java/net/floodlightcontroller/linkdiscovery/ILinkDiscovery.java

@@ -103,6 +103,29 @@ public interface ILinkDiscovery {
     };
 
     public enum LinkType {
-        INVALID_LINK, DIRECT_LINK, MULTIHOP_LINK, TUNNEL
+        INVALID_LINK {
+        	@Override
+        	public String toString() {
+        		return "invalid";
+        	}
+        }, 
+        DIRECT_LINK{
+        	@Override
+        	public String toString() {
+        		return "internal";
+        	}
+        }, 
+        MULTIHOP_LINK {
+        	@Override
+        	public String toString() {
+        		return "external";
+        	}
+        }, 
+        TUNNEL {
+        	@Override
+        	public String toString() {
+        		return "tunnel";
+        	}
+        }
     };
 }

src/main/java/net/floodlightcontroller/linkdiscovery/web/LinkWithType.java

+package net.floodlightcontroller.linkdiscovery.web;
+
+import java.io.IOException;
+
+import org.codehaus.jackson.JsonGenerator;
+import org.codehaus.jackson.JsonProcessingException;
+import org.codehaus.jackson.map.JsonSerializer;
+import org.codehaus.jackson.map.SerializerProvider;
+import org.codehaus.jackson.map.annotate.JsonSerialize;
+import org.openflow.util.HexString;
+
+import net.floodlightcontroller.linkdiscovery.ILinkDiscovery.LinkType;
+import net.floodlightcontroller.routing.Link;
+
+/**
+ * This class is both the datastructure and the serializer
+ * for a link with the corresponding type of link.
+ * @author alexreimers
+ */
+@JsonSerialize(using=LinkWithType.class)
+public class LinkWithType extends JsonSerializer<LinkWithType> {
+    public long srcSwDpid;
+    public short srcPort;
+    public long dstSwDpid;
+    public short dstPort;
+    public LinkType type;
+
+    // Do NOT delete this, it's required for the serializer
+    public LinkWithType() {}
+    
+    public LinkWithType(Link link, LinkType type) {
+        this.srcSwDpid = link.getSrc();
+        this.srcPort = link.getSrcPort();
+        this.dstSwDpid = link.getDst();
+        this.dstPort = link.getDstPort();
+        this.type = type;
+    }
+
+	@Override
+	public void serialize(LinkWithType lwt, JsonGenerator jgen, SerializerProvider arg2) 
+			throws IOException, JsonProcessingException {
+		// You ****MUST*** use lwt for the fields as it's actually a different object.
+		jgen.writeStartObject();
+		jgen.writeStringField("src-switch", HexString.toHexString(lwt.srcSwDpid));
+		jgen.writeNumberField("src-port", lwt.srcPort);
+		jgen.writeStringField("dst-switch", HexString.toHexString(lwt.dstSwDpid));
+		jgen.writeNumberField("dst-port", lwt.dstPort);
+		jgen.writeStringField("type", lwt.type.toString());
+		jgen.writeEndObject();
+	}
+	
+	@Override
+	public Class<LinkWithType> handledType() {
+		return LinkWithType.class;
+	}
+}
\ No newline at end of file

src/main/java/net/floodlightcontroller/linkdiscovery/web/LinksResource.java

@@ -5,7 +5,6 @@ import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
 
-import net.floodlightcontroller.linkdiscovery.ILinkDiscovery.LinkType;
 import net.floodlightcontroller.linkdiscovery.ILinkDiscoveryService;
 import net.floodlightcontroller.linkdiscovery.LinkInfo;
 import net.floodlightcontroller.routing.Link;
@@ -15,26 +14,8 @@ import org.restlet.resource.ServerResource;
 
 public class LinksResource extends ServerResource {
 
-    public class LinkWithType {
-        long src;
-        short srcPort;
-        long dst;
-        short dstPort;
-        String type;
-
-        public LinkWithType(Link link, String type) {
-            this.src = link.getSrc();
-            this.srcPort = link.getSrcPort();
-            this.dst = link.getDst();
-            this.dstPort = link.getDstPort();
-            this.type = type;
-        }
-    };
-
     @Get("json")
     public Set<LinkWithType> retrieve() {
-        String str;
-
         ILinkDiscoveryService ld = (ILinkDiscoveryService)getContext().getAttributes().
                 get(ILinkDiscoveryService.class.getCanonicalName());
         Map<Link, LinkInfo> links = new HashMap<Link, LinkInfo>();
@@ -44,17 +25,7 @@ public class LinksResource extends ServerResource {
             links.putAll(ld.getLinks());
             for (Link link: links.keySet()) {
                 LinkInfo info = links.get(link);
-                LinkType type = ld.getLinkType(info);
-
-                if (type == LinkType.DIRECT_LINK) 
-                    str = "internal";
-                else if (type == LinkType.MULTIHOP_LINK)
-                    str = "external";
-                else if (type == LinkType.TUNNEL)
-                    str = "tunnel";
-                else str = "invalid";
-
-                LinkWithType lwt = new LinkWithType(link, str);
+                LinkWithType lwt = new LinkWithType(link, ld.getLinkType(info));
                 returnLinkSet.add(lwt);
             }
         }