From 6e51370490bfda56d4ce68b1acaffb858df7af46 Mon Sep 17 00:00:00 2001
From: Rossen Stoyanchev <rstoyanchev@vmware.com>
Date: Fri, 6 Nov 2020 20:46:35 +0000
Subject: [PATCH] AbstractJackson2Encoder support for MappingJacksonValue

Closes gh-26035
---
 .../codec/json/AbstractJackson2Encoder.java   | 23 +++++++++++++++----
 .../codec/json/Jackson2JsonEncoderTests.java  | 20 ++++++++++++++++
 2 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/spring-web/src/main/java/org/springframework/http/codec/json/AbstractJackson2Encoder.java b/spring-web/src/main/java/org/springframework/http/codec/json/AbstractJackson2Encoder.java
index ae90df4115f..a5bfda5625f 100644
--- a/spring-web/src/main/java/org/springframework/http/codec/json/AbstractJackson2Encoder.java
+++ b/spring-web/src/main/java/org/springframework/http/codec/json/AbstractJackson2Encoder.java
@@ -34,6 +34,7 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.ObjectWriter;
 import com.fasterxml.jackson.databind.SequenceWriter;
 import com.fasterxml.jackson.databind.exc.InvalidDefinitionException;
+import com.fasterxml.jackson.databind.ser.FilterProvider;
 import org.reactivestreams.Publisher;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
@@ -48,6 +49,7 @@ import org.springframework.core.io.buffer.DataBufferFactory;
 import org.springframework.core.log.LogFormatUtils;
 import org.springframework.http.MediaType;
 import org.springframework.http.codec.HttpMessageEncoder;
+import org.springframework.http.converter.json.MappingJacksonValue;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpResponse;
 import org.springframework.lang.Nullable;
@@ -148,7 +150,7 @@ public abstract class AbstractJackson2Encoder extends Jackson2CodecSupport imple
 			byte[] separator = getStreamingMediaTypeSeparator(mimeType);
 			if (separator != null) { // streaming
 				try {
-					ObjectWriter writer = createObjectWriter(elementType, mimeType, hints);
+					ObjectWriter writer = createObjectWriter(elementType, mimeType, null, hints);
 					ByteArrayBuilder byteBuilder = new ByteArrayBuilder(writer.getFactory()._getBufferRecycler());
 					JsonEncoding encoding = getJsonEncoding(mimeType);
 					JsonGenerator generator = getObjectMapper().getFactory().createGenerator(byteBuilder, encoding);
@@ -186,7 +188,18 @@ public abstract class AbstractJackson2Encoder extends Jackson2CodecSupport imple
 	public DataBuffer encodeValue(Object value, DataBufferFactory bufferFactory,
 			ResolvableType valueType, @Nullable MimeType mimeType, @Nullable Map<String, Object> hints) {
 
-		ObjectWriter writer = createObjectWriter(valueType, mimeType, hints);
+		Class<?> jsonView = null;
+		FilterProvider filters = null;
+		if (value instanceof MappingJacksonValue) {
+			MappingJacksonValue container = (MappingJacksonValue) value;
+			value = container.getValue();
+			jsonView = container.getSerializationView();
+			filters = container.getFilters();
+		}
+		ObjectWriter writer = createObjectWriter(valueType, mimeType, jsonView, hints);
+		if (filters != null) {
+			writer = writer.with(filters);
+		}
 		ByteArrayBuilder byteBuilder = new ByteArrayBuilder(writer.getFactory()._getBufferRecycler());
 		try {
 			JsonEncoding encoding = getJsonEncoding(mimeType);
@@ -268,10 +281,12 @@ public abstract class AbstractJackson2Encoder extends Jackson2CodecSupport imple
 	}
 
 	private ObjectWriter createObjectWriter(ResolvableType valueType, @Nullable MimeType mimeType,
-			@Nullable Map<String, Object> hints) {
+			@Nullable Class<?> jsonView, @Nullable Map<String, Object> hints) {
 
 		JavaType javaType = getJavaType(valueType.getType(), null);
-		Class<?> jsonView = (hints != null ? (Class<?>) hints.get(Jackson2CodecSupport.JSON_VIEW_HINT) : null);
+		if (jsonView == null && hints != null) {
+			jsonView = (Class<?>) hints.get(Jackson2CodecSupport.JSON_VIEW_HINT);
+		}
 		ObjectWriter writer = (jsonView != null ?
 				getObjectMapper().writerWithView(jsonView) : getObjectMapper().writer());
 
diff --git a/spring-web/src/test/java/org/springframework/http/codec/json/Jackson2JsonEncoderTests.java b/spring-web/src/test/java/org/springframework/http/codec/json/Jackson2JsonEncoderTests.java
index 0a9d3274126..ebeed1493b7 100644
--- a/spring-web/src/test/java/org/springframework/http/codec/json/Jackson2JsonEncoderTests.java
+++ b/spring-web/src/test/java/org/springframework/http/codec/json/Jackson2JsonEncoderTests.java
@@ -39,6 +39,7 @@ import org.springframework.http.MediaType;
 import org.springframework.http.codec.ServerSentEvent;
 import org.springframework.http.codec.json.JacksonViewBean.MyJacksonView1;
 import org.springframework.http.codec.json.JacksonViewBean.MyJacksonView3;
+import org.springframework.http.converter.json.MappingJacksonValue;
 import org.springframework.util.MimeType;
 import org.springframework.util.MimeTypeUtils;
 import org.springframework.web.testfixture.xml.Pojo;
@@ -214,6 +215,25 @@ public class Jackson2JsonEncoderTests extends AbstractEncoderTests<Jackson2JsonE
 				null, hints);
 	}
 
+	@Test
+	public void jacksonValue() {
+		JacksonViewBean bean = new JacksonViewBean();
+		bean.setWithView1("with");
+		bean.setWithView2("with");
+		bean.setWithoutView("without");
+
+		MappingJacksonValue jacksonValue = new MappingJacksonValue(bean);
+		jacksonValue.setSerializationView(MyJacksonView1.class);
+
+		ResolvableType type = ResolvableType.forClass(MappingJacksonValue.class);
+
+		testEncode(Mono.just(jacksonValue), type, step -> step
+						.consumeNextWith(expectString("{\"withView1\":\"with\"}")
+								.andThen(DataBufferUtils::release))
+						.verifyComplete(),
+				null, Collections.emptyMap());
+	}
+
 	@Test // gh-22771
 	public void encodeWithFlushAfterWriteOff() {
 		ObjectMapper mapper = new ObjectMapper();