| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.hadoop.hdds.server; |
| |
| import java.io.IOException; |
| import java.util.List; |
| |
| import com.fasterxml.jackson.annotation.JsonInclude; |
| import com.fasterxml.jackson.databind.ObjectMapper; |
| import com.fasterxml.jackson.databind.ObjectWriter; |
| import com.fasterxml.jackson.databind.SerializationFeature; |
| import com.fasterxml.jackson.databind.node.ArrayNode; |
| import com.fasterxml.jackson.databind.node.ObjectNode; |
| import com.fasterxml.jackson.databind.type.CollectionType; |
| import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule; |
| |
| /** |
| * JSON Utility functions used in ozone. |
| */ |
| public final class JsonUtils { |
| |
| // Reuse ObjectMapper instance for improving performance. |
| // ObjectMapper is thread safe as long as we always configure instance |
| // before use. |
| private static final ObjectMapper MAPPER; |
| private static final ObjectWriter WRITER; |
| static { |
| MAPPER = new ObjectMapper() |
| .setSerializationInclusion(JsonInclude.Include.NON_NULL) |
| .registerModule(new JavaTimeModule()) |
| .configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false); |
| WRITER = MAPPER.writerWithDefaultPrettyPrinter(); |
| } |
| |
| private JsonUtils() { |
| // Never constructed |
| } |
| |
| public static String toJsonStringWithDefaultPrettyPrinter(Object obj) |
| throws IOException { |
| return WRITER.writeValueAsString(obj); |
| } |
| |
| public static String toJsonString(Object obj) throws IOException { |
| return MAPPER.writeValueAsString(obj); |
| } |
| |
| public static ArrayNode createArrayNode() { |
| return MAPPER.createArrayNode(); |
| } |
| |
| public static ObjectNode createObjectNode(Object next) { |
| return MAPPER.valueToTree(next); |
| } |
| |
| /** |
| * Deserialize a list of elements from a given string, |
| * each element in the list is in the given type. |
| * |
| * @param str json string. |
| * @param elementType element type. |
| * @return List of elements of type elementType |
| * @throws IOException |
| */ |
| public static List<?> toJsonList(String str, Class<?> elementType) |
| throws IOException { |
| CollectionType type = MAPPER.getTypeFactory() |
| .constructCollectionType(List.class, elementType); |
| return MAPPER.readValue(str, type); |
| } |
| } |