[ONOS-4986] [ONOS-4985] Json defect fix

Change-Id: I50876404fa75ca0dd9d30ab255ae800430147fae

@@ -47,7 +47,7 @@ public class PceUpdatePathCommand extends AbstractShellCommand {
 
     @Option(name = "-c", aliases = "--cost", description = "The cost attribute IGP cost (1) or TE cost (2).",
             required = false, multiValued = false)
-    int cost = -1;
+    Integer cost = null;
 
     @Option(name = "-b", aliases = "--bandwidth", description = "The bandwidth attribute of path. "
             + "Data rate unit is in Bps.", required = false, multiValued = false)
@@ -66,7 +66,7 @@ public class PceUpdatePathCommand extends AbstractShellCommand {
         }
 
         // Cost validation
-        if (cost != -1) {
+        if (cost != null) {
             if ((cost < 1) || (cost > 2)) {
                 error("The cost attribute value is either IGP cost(1) or TE cost(2).");
                 return;

@@ -508,7 +508,7 @@ public class PceManager implements PceService {
             }
 
             if (existingBwValue != null) {
-                if (bwConstraintValue == 0 && bwConstraint != null) {
+                if (bwConstraint == null) {
                     bwConstraintValue = existingBwValue.bps();
                 }
                 //If bandwidth constraints not specified , take existing bandwidth for shared bandwidth calculation

@@ -101,6 +101,9 @@ public class PcePathWebResource extends AbstractWebResource {
         Tunnel tunnel = nullIsNotFound(get(PceService.class).queryPath(TunnelId.valueOf(id)),
                                        PCE_PATH_NOT_FOUND);
         PcePath path = DefaultPcePath.builder().of(tunnel).build();
+        if (path == null) {
+            return Response.status(OK).entity(PCE_SETUP_PATH_FAILED).build();
+        }
         ObjectNode result = mapper().createObjectNode();
         result.set("path", codec(PcePath.class).encode(path, this));
         return ok(result.toString()).build();
@@ -175,6 +178,9 @@ public class PcePathWebResource extends AbstractWebResource {
             ObjectNode jsonTree = (ObjectNode) mapper().readTree(stream);
             JsonNode pathNode = jsonTree.get("path");
             PcePath path = codec(PcePath.class).decode((ObjectNode) pathNode, this);
+            if (path == null) {
+                return Response.status(OK).entity(PCE_SETUP_PATH_FAILED).build();
+            }
             List<Constraint> constrntList = new LinkedList<Constraint>();
             // Assign bandwidth
             if (path.bandwidthConstraint() != null) {