ajorgensen commented on a change in pull request #2842: Add json format for dry-run URL: https://github.com/apache/incubator-heron/pull/2842#discussion_r179232704
########## File path: heron/scheduler-core/src/java/com/twitter/heron/scheduler/dryrun/JsonFormatterUtils.java ########## @@ -0,0 +1,87 @@ +// Copyright 2018 Twitter. All rights reserved. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. +package com.twitter.heron.scheduler.dryrun; + +import com.fasterxml.jackson.core.JsonProcessingException; +import com.fasterxml.jackson.databind.ObjectMapper; +import com.fasterxml.jackson.databind.node.ArrayNode; +import com.fasterxml.jackson.databind.node.ObjectNode; + +import com.twitter.heron.spi.packing.PackingPlan; +import com.twitter.heron.spi.packing.Resource; + +public class JsonFormatterUtils { + + private final ObjectMapper mapper; Review comment: FWIW here's a comment on StackOverflow regarding re-usability. >It's fine to use a single instance per application provided you don't call any configuration methods after it's been made visible i.e. you should do all your initialization inside a static block. https://stackoverflow.com/questions/18611565/how-do-i-correctly-reuse-jackson-objectmapper Given that the documentation mentions that it's thread-safe and I am not storing any of the intermediate steps in instance variables I think this should be safe from both a re-usability standpoint and thread-safety standpoint as written but I can defer to someone who has more jackson experience to weigh in as well. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
