Java tutorial
/* * Copyright 2011-2019 Amazon Technologies, Inc. * * 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://aws.amazon.com/apache2.0 * * This file 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.amazonaws.util.json; import com.amazonaws.log.InternalLogApi; import com.amazonaws.log.InternalLogFactory; import com.fasterxml.jackson.core.JsonParseException; import com.fasterxml.jackson.core.JsonProcessingException; import java.io.File; import java.io.IOException; import java.io.Writer; import com.amazonaws.SdkClientException; import com.fasterxml.jackson.core.JsonFactory; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.databind.DeserializationFeature; import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.ObjectWriter; public enum Jackson { ; private static final InternalLogApi log = InternalLogFactory.getLog(Jackson.class); private static final ObjectMapper objectMapper = new ObjectMapper(); static { objectMapper.configure(JsonParser.Feature.ALLOW_COMMENTS, true); objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false); } private static final ObjectWriter writer = objectMapper.writer(); private static final ObjectWriter prettyWriter = objectMapper.writerWithDefaultPrettyPrinter(); public static String toJsonPrettyString(Object value) { try { return prettyWriter.writeValueAsString(value); } catch (Exception e) { throw new IllegalStateException(e); } } public static String toJsonString(Object value) { try { return writer.writeValueAsString(value); } catch (Exception e) { throw new IllegalStateException(e); } } /** * Returns the deserialized object from the given json string and target * class; or null if the given json string is null. */ public static <T> T fromJsonString(String json, Class<T> clazz) { if (json == null) return null; try { return objectMapper.readValue(json, clazz); } catch (Exception e) { throw new SdkClientException("Unable to parse Json String.", e); } } /** * Returns the deserialized object from the given json string and target * class; or null if the given json string is null. Clears the JSON location in the event of an error */ public static <T> T fromSensitiveJsonString(String json, Class<T> clazz) { if (json == null) { return null; } try { return objectMapper.readValue(json, clazz); } catch (IOException e) { // If underlying exception is a json parsing issue, clear out the location so that the exception message // does not contain the raw json if (e instanceof JsonProcessingException) { log.debug("Failed to parse JSON string.", e); throw new SdkClientException( "Unable to parse Json string. See debug-level logs for the exact error " + "details, which may include sensitive information."); } throw new SdkClientException("Unable to parse Json String.", e); } } public static JsonNode jsonNodeOf(String json) { return fromJsonString(json, JsonNode.class); } public static JsonGenerator jsonGeneratorOf(Writer writer) throws IOException { return new JsonFactory().createGenerator(writer); } public static <T> T loadFrom(File file, Class<T> clazz) throws IOException { try { return objectMapper.readValue(file, clazz); } catch (IOException e) { throw e; } catch (Exception e) { throw new IllegalStateException(e); } } public static ObjectMapper getObjectMapper() { return objectMapper; } public static ObjectWriter getWriter() { return writer; } public static ObjectWriter getPrettywriter() { return prettyWriter; } }