Clean up source code of REST API

- Add missing @Produces annotation
- Correct comments
- Restrict variable access level

Change-Id: I7f75650b83651248370e7781b1e8aec7eac2314c
diff --git a/web/api/src/main/java/org/onosproject/rest/resources/ComponentConfigWebResource.java b/web/api/src/main/java/org/onosproject/rest/resources/ComponentConfigWebResource.java
index cc57581..d1a8ff7 100644
--- a/web/api/src/main/java/org/onosproject/rest/resources/ComponentConfigWebResource.java
+++ b/web/api/src/main/java/org/onosproject/rest/resources/ComponentConfigWebResource.java
@@ -26,6 +26,7 @@
 import javax.ws.rs.POST;
 import javax.ws.rs.Path;
 import javax.ws.rs.PathParam;
+import javax.ws.rs.Produces;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
 import java.io.IOException;
@@ -41,12 +42,13 @@
 public class ComponentConfigWebResource extends AbstractWebResource {
 
     /**
-     * Get all component configurations.
+     * Gets all component configurations.
      * Returns collection of all registered component configurations.
      *
-     * @return 200 OK
+     * @return 200 OK with a collection of component configurations
      */
     @GET
+    @Produces(MediaType.APPLICATION_JSON)
     public Response getComponentConfigs() {
         ComponentConfigService service = get(ComponentConfigService.class);
         Set<String> components = service.getComponentNames();
@@ -56,13 +58,14 @@
     }
 
     /**
-     * Get configuration of the specified component.
+     * Gets configuration of the specified component.
      *
      * @param component component name
-     * @return 200 OK
+     * @return 200 OK with a collection of component configurations
      */
     @GET
     @Path("{component}")
+    @Produces(MediaType.APPLICATION_JSON)
     public Response getComponentConfigs(@PathParam("component") String component) {
         ComponentConfigService service = get(ComponentConfigService.class);
         ObjectNode root = mapper().createObjectNode();
@@ -80,7 +83,7 @@
     }
 
     /**
-     * Selectively set configuration properties.
+     * Selectively sets configuration properties.
      * Sets only the properties present in the JSON request.
      *
      * @param component component name
@@ -97,11 +100,11 @@
         ObjectNode props = (ObjectNode) mapper().readTree(request);
         props.fieldNames().forEachRemaining(k -> service.setProperty(component, k,
                                                                      props.path(k).asText()));
-        return Response.noContent().build();
+        return Response.ok().build();
     }
 
     /**
-     * Selectively clear configuration properties.
+     * Selectively clears configuration properties.
      * Clears only the properties present in the JSON request.
      *
      * @param component component name