Improve Jackson codecs documentation

spring-web/src/main/java/org/springframework/http/codec/json/AbstractJackson2Decoder.java

@@ -46,12 +46,13 @@ import org.springframework.util.Assert;
 import org.springframework.util.MimeType;
 
 /**
- * Abstract base class for Jackson JSON 2.9 decoding.
+ * Abstract base class for Jackson 2.9 decoding, leveraging non-blocking parsing.
  *
  * @author Sebastien Deleuze
  * @author Rossen Stoyanchev
  * @author Arjen Poutsma
  * @since 5.0
+ * @see <a href="https://github.com/FasterXML/jackson-core/issues/57" target="_blank">Add support for non-blocking ("async") JSON parsing</a>
  */
 public abstract class AbstractJackson2Decoder extends Jackson2CodecSupport implements HttpMessageDecoder<Object> {
 

spring-web/src/main/java/org/springframework/http/codec/json/AbstractJackson2Encoder.java

@@ -48,7 +48,9 @@ import org.springframework.util.Assert;
 import org.springframework.util.MimeType;
 
 /**
- * Base class providing support methods for Jackson 2.9 encoding.
+ * Base class providing support methods for Jackson 2.9 encoding. For non-streaming use
+ * cases, {@link Flux} elements are collected into a {@link List} before serialization for
+ * performance reason.
  *
  * @author Sebastien Deleuze
  * @author Arjen Poutsma

spring-web/src/main/java/org/springframework/http/codec/json/Jackson2JsonDecoder.java

@@ -24,7 +24,8 @@ import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
 import org.springframework.util.MimeType;
 
 /**
- * Decode a byte stream into JSON and convert to Object's with Jackson 2.9.
+ * Decode a byte stream into JSON and convert to Object's with Jackson 2.9,
+ * leveraging non-blocking parsing.
  *
  * @author Sebastien Deleuze
  * @author Rossen Stoyanchev

spring-web/src/main/java/org/springframework/http/codec/json/Jackson2JsonEncoder.java

@@ -25,6 +25,7 @@ import com.fasterxml.jackson.core.util.DefaultPrettyPrinter;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.ObjectWriter;
 import com.fasterxml.jackson.databind.SerializationFeature;
+import reactor.core.publisher.Flux;
 
 import org.springframework.core.ResolvableType;
 import org.springframework.http.MediaType;
@@ -33,8 +34,9 @@ import org.springframework.lang.Nullable;
 import org.springframework.util.MimeType;
 
 /**
- * Encode from an {@code Object} stream to a byte stream of JSON objects,
- * using Jackson 2.9.
+ * Encode from an {@code Object} stream to a byte stream of JSON objects using Jackson 2.9.
+ * For non-streaming use cases, {@link Flux} elements are collected into a {@link List}
+ * before serialization for performance reason.
  *
  * @author Sebastien Deleuze
  * @author Arjen Poutsma

spring-web/src/main/java/org/springframework/http/codec/json/Jackson2SmileDecoder.java

@@ -28,7 +28,8 @@ import org.springframework.util.Assert;
 import org.springframework.util.MimeType;
 
 /**
- * Decode a byte stream into Smile and convert to Object's with Jackson 2.9.
+ * Decode a byte stream into Smile and convert to Object's with Jackson 2.9,
+ * leveraging non-blocking parsing.
  *
  * @author Sebastien Deleuze
  * @author Rossen Stoyanchev

spring-web/src/main/java/org/springframework/http/codec/json/Jackson2SmileEncoder.java

@@ -21,6 +21,7 @@ import java.util.List;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.dataformat.smile.SmileFactory;
+import reactor.core.publisher.Flux;
 
 import org.springframework.http.MediaType;
 import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
@@ -29,6 +30,8 @@ import org.springframework.util.MimeType;
 
 /**
  * Encode from an {@code Object} stream to a byte stream of Smile objects using Jackson 2.9.
+ * For non-streaming use cases, {@link Flux} elements are collected into a {@link List}
+ * before serialization for performance reason.
  *
  * @author Sebastien Deleuze
  * @since 5.0

src/docs/asciidoc/core/core-databuffer-codec.adoc

@@ -160,7 +160,7 @@ Note that a decoder instance needs to consider <<databuffer-reference-counting,
 
 Spring comes with a wide array of default codecs, capable of converting from/to `String`,
 `ByteBuffer`, byte arrays, and also codecs that support marshalling libraries such as JAXB and
-Jackson.
+Jackson (with https://github.com/FasterXML/jackson-core/issues/57[Jackson 2.9+ support for non-blocking parsing]).
 Withing the context of Spring WebFlux, codecs are used to convert the request body into a
 `@RequestMapping` parameter, or to convert the return type into the response body that is sent back
 to the client.