Merge branch 'change/api/isExistingApp' into 'master'

Change API that checks if an appName already exists, to accept the appName as query parameter

See merge request entgra/carbon-device-mgt!824

components/application-mgt/io.entgra.application.mgt.publisher.api/src/main/java/io/entgra/application/mgt/publisher/api/services/ApplicationManagementPublisherAPI.java

@@ -683,7 +683,7 @@ public interface ApplicationManagementPublisherAPI {
     );
 
     @GET
-    @Path("/device-type/{deviceType}/app-name/{appName}")
+    @Path("/device-type/{deviceType}/app-name")
     @ApiOperation(
             httpMethod = "GET",
             value = "Check the application existence",
@@ -723,7 +723,7 @@ public interface ApplicationManagementPublisherAPI {
                     name = "appName",
                     value = "Application name",
                     required = true)
-            @PathParam("appName") String appName
+            @QueryParam("appName") String appName
     );
 
     @PUT

components/application-mgt/io.entgra.application.mgt.publisher.api/src/main/java/io/entgra/application/mgt/publisher/api/services/impl/ApplicationManagementPublisherAPIImpl.java

@@ -390,11 +390,16 @@ public class ApplicationManagementPublisherAPIImpl implements ApplicationManagem
 
     @Override
     @GET
-    @Path("/device-type/{deviceType}/app-name/{appName}")
+    @Path("/device-type/{deviceType}/app-name")
     public Response isExistingApplication(
             @PathParam("deviceType") String deviceType,
-            @PathParam("appName") String appName ){
+            @QueryParam("appName") String appName){
         try {
+            if (appName == null) {
+                String msg = "Invalid app name, appName query param cannot be empty/null.";
+                log.error(msg);
+                return Response.status(Response.Status.BAD_REQUEST).build();
+            }
             ApplicationManager applicationManager = APIUtil.getApplicationManager();
             if (applicationManager.isExistingAppName(appName, deviceType)) {
                 return Response.status(Response.Status.CONFLICT).build();