001/* 002 * Copyright 2002-2018 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.http.codec.json; 018 019import java.util.Collections; 020import java.util.List; 021import java.util.Map; 022 023import com.fasterxml.jackson.core.PrettyPrinter; 024import com.fasterxml.jackson.core.util.DefaultIndenter; 025import com.fasterxml.jackson.core.util.DefaultPrettyPrinter; 026import com.fasterxml.jackson.databind.ObjectMapper; 027import com.fasterxml.jackson.databind.ObjectWriter; 028import com.fasterxml.jackson.databind.SerializationFeature; 029import reactor.core.publisher.Flux; 030 031import org.springframework.core.ResolvableType; 032import org.springframework.http.MediaType; 033import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder; 034import org.springframework.lang.Nullable; 035import org.springframework.util.MimeType; 036 037/** 038 * Encode from an {@code Object} stream to a byte stream of JSON objects using Jackson 2.9. 039 * For non-streaming use cases, {@link Flux} elements are collected into a {@link List} 040 * before serialization for performance reason. 041 * 042 * @author Sebastien Deleuze 043 * @author Arjen Poutsma 044 * @since 5.0 045 * @see Jackson2JsonDecoder 046 */ 047public class Jackson2JsonEncoder extends AbstractJackson2Encoder { 048 049 @Nullable 050 private final PrettyPrinter ssePrettyPrinter; 051 052 053 public Jackson2JsonEncoder() { 054 this(Jackson2ObjectMapperBuilder.json().build()); 055 } 056 057 public Jackson2JsonEncoder(ObjectMapper mapper, MimeType... mimeTypes) { 058 super(mapper, mimeTypes); 059 setStreamingMediaTypes(Collections.singletonList(MediaType.APPLICATION_STREAM_JSON)); 060 this.ssePrettyPrinter = initSsePrettyPrinter(); 061 } 062 063 private static PrettyPrinter initSsePrettyPrinter() { 064 DefaultPrettyPrinter printer = new DefaultPrettyPrinter(); 065 printer.indentObjectsWith(new DefaultIndenter(" ", "\ndata:")); 066 return printer; 067 } 068 069 070 @Override 071 protected ObjectWriter customizeWriter(ObjectWriter writer, @Nullable MimeType mimeType, 072 ResolvableType elementType, @Nullable Map<String, Object> hints) { 073 074 return (this.ssePrettyPrinter != null && 075 MediaType.TEXT_EVENT_STREAM.isCompatibleWith(mimeType) && 076 writer.getConfig().isEnabled(SerializationFeature.INDENT_OUTPUT) ? 077 writer.with(this.ssePrettyPrinter) : writer); 078 } 079 080}