Merge pull request #37885 from eddumelendez

* gh-37885:
  Polish "Add properties for configuring EnumFeature and JsonNodeFeature"
  Add properties for configuring EnumFeature and JsonNodeFeature

Closes gh-37885

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jackson/JacksonAutoConfiguration.java

@@ -213,6 +213,8 @@ public class JacksonAutoConfiguration {
 				configureFeatures(builder, this.jacksonProperties.getMapper());
 				configureFeatures(builder, this.jacksonProperties.getParser());
 				configureFeatures(builder, this.jacksonProperties.getGenerator());
+				configureFeatures(builder, this.jacksonProperties.getDatatype().getEnum());
+				configureFeatures(builder, this.jacksonProperties.getDatatype().getJsonNode());
 				configureDateFormat(builder);
 				configurePropertyNamingStrategy(builder);
 				configureModules(builder);

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jackson/JacksonProperties.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -29,6 +29,8 @@ import com.fasterxml.jackson.core.JsonParser;
 import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.MapperFeature;
 import com.fasterxml.jackson.databind.SerializationFeature;
+import com.fasterxml.jackson.databind.cfg.EnumFeature;
+import com.fasterxml.jackson.databind.cfg.JsonNodeFeature;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
@@ -38,6 +40,7 @@ import org.springframework.boot.context.properties.ConfigurationProperties;
  * @author Andy Wilkinson
  * @author Marcel Overdijk
  * @author Johannes Edmeier
+ * @author Eddú Meléndez
  * @since 1.2.0
  */
 @ConfigurationProperties(prefix = "spring.jackson")
@@ -114,6 +117,8 @@ public class JacksonProperties {
 	 */
 	private Locale locale;
 
+	private final Datatype datatype = new Datatype();
+
 	public String getDateFormat() {
 		return this.dateFormat;
 	}
@@ -194,6 +199,10 @@ public class JacksonProperties {
 		this.locale = locale;
 	}
 
+	public Datatype getDatatype() {
+		return this.datatype;
+	}
+
 	public enum ConstructorDetectorStrategy {
 
 		/**
@@ -219,4 +228,26 @@ public class JacksonProperties {
 
 	}
 
+	public static class Datatype {
+
+		/**
+		 * Jackson on/off features for enums.
+		 */
+		private final Map<EnumFeature, Boolean> enumFeatures = new EnumMap<>(EnumFeature.class);
+
+		/**
+		 * Jackson on/off features for JsonNodes.
+		 */
+		private final Map<JsonNodeFeature, Boolean> jsonNode = new EnumMap<>(JsonNodeFeature.class);
+
+		public Map<EnumFeature, Boolean> getEnum() {
+			return this.enumFeatures;
+		}
+
+		public Map<JsonNodeFeature, Boolean> getJsonNode() {
+			return this.jsonNode;
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-autoconfigure/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -1559,6 +1559,10 @@
       "name": "spring.jackson.constructor-detector",
       "defaultValue": "default"
     },
+    {
+      "name": "spring.jackson.datatype.enum",
+      "description": "Jackson on/off features for enums."
+    },
     {
       "name": "spring.jackson.joda-date-time-format",
       "type": "java.lang.String",

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jackson/JacksonAutoConfigurationTests.java

@@ -45,6 +45,8 @@ import com.fasterxml.jackson.databind.SerializationFeature;
 import com.fasterxml.jackson.databind.SerializerProvider;
 import com.fasterxml.jackson.databind.cfg.ConstructorDetector;
 import com.fasterxml.jackson.databind.cfg.ConstructorDetector.SingleArgConstructor;
+import com.fasterxml.jackson.databind.cfg.EnumFeature;
+import com.fasterxml.jackson.databind.cfg.JsonNodeFeature;
 import com.fasterxml.jackson.databind.exc.InvalidFormatException;
 import com.fasterxml.jackson.databind.module.SimpleModule;
 import com.fasterxml.jackson.databind.util.StdDateFormat;
@@ -88,6 +90,7 @@ import static org.mockito.Mockito.mock;
  * @author Johannes Edmeier
  * @author Grzegorz Poznachowski
  * @author Ralf Ueberfuhr
+ * @author Eddú Meléndez
  */
 class JacksonAutoConfigurationTests {
 
@@ -289,6 +292,27 @@ class JacksonAutoConfigurationTests {
 		});
 	}
 
+	@Test
+	void enableEnumFeature() {
+		this.contextRunner.withPropertyValues("spring.jackson.datatype.enum.write-enums-to-lowercase=true")
+			.run((context) -> {
+				ObjectMapper mapper = context.getBean(ObjectMapper.class);
+				assertThat(EnumFeature.WRITE_ENUMS_TO_LOWERCASE.enabledByDefault()).isFalse();
+				assertThat(mapper.getSerializationConfig().isEnabled(EnumFeature.WRITE_ENUMS_TO_LOWERCASE)).isTrue();
+			});
+	}
+
+	@Test
+	void disableJsonNodeFeature() {
+		this.contextRunner.withPropertyValues("spring.jackson.datatype.jsonnode.write-null-properties:false")
+			.run((context) -> {
+				ObjectMapper mapper = context.getBean(ObjectMapper.class);
+				assertThat(JsonNodeFeature.WRITE_NULL_PROPERTIES.enabledByDefault()).isTrue();
+				assertThat(mapper.getDeserializationConfig().isEnabled(JsonNodeFeature.WRITE_NULL_PROPERTIES))
+					.isFalse();
+			});
+	}
+
 	@Test
 	void moduleBeansAndWellKnownModulesAreRegisteredWithTheObjectMapperBuilder() {
 		this.contextRunner.withUserConfiguration(ModuleConfig.class).run((context) -> {

spring-boot-project/spring-boot-docs/src/docs/asciidoc/howto/spring-mvc.adoc

@@ -64,11 +64,19 @@ Spring Boot also has some features to make it easier to customize this behavior.
 
 You can configure the `ObjectMapper` and `XmlMapper` instances by using the environment.
 Jackson provides an extensive suite of on/off features that can be used to configure various aspects of its processing.
-These features are described in six enums (in Jackson) that map onto properties in the environment:
+These features are described in several enums (in Jackson) that map onto properties in the environment:
 
 |===
 | Enum | Property | Values
 
+| `com.fasterxml.jackson.databind.cfg.EnumFeature`
+| `spring.jackson.datatype.enum.<feature_name>`
+| `true`, `false`
+
+| `com.fasterxml.jackson.databind.cfg.JsonNodeFeature`
+| `spring.jackson.datatype.jsonnode.<feature_name>`
+| `true`, `false`
+
 | `com.fasterxml.jackson.databind.DeserializationFeature`
 | `spring.jackson.deserialization.<feature_name>`
 | `true`, `false`