Add Consumer methods to configure Jackson modules

Closes gh-28633

Author: rstoyanchev

spring-web/src/main/java/org/springframework/http/converter/json/Jackson2ObjectMapperBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -521,7 +521,7 @@ public Jackson2ObjectMapperBuilder featuresToDisable(Object... featuresToDisable
 	}
 
 	/**
-	 * Specify one or more modules to be registered with the {@link ObjectMapper}.
+	 * Specify the modules to be registered with the {@link ObjectMapper}.
 	 * <p>Multiple invocations are not additive, the last one defines the modules to
 	 * register.
 	 * <p>Note: If this is set, no finding of modules is going to happen - not by
@@ -538,15 +538,9 @@ public Jackson2ObjectMapperBuilder modules(Module... modules) {
 	}
 
 	/**
-	 * Set a complete list of modules to be registered with the {@link ObjectMapper}.
-	 * <p>Multiple invocations are not additive, the last one defines the modules to
-	 * register.
-	 * <p>Note: If this is set, no finding of modules is going to happen - not by
-	 * Jackson, and not by Spring either (see {@link #findModulesViaServiceLoader}).
-	 * As a consequence, specifying an empty list here will suppress any kind of
-	 * module detection.
-	 * <p>Specify either this or {@link #modulesToInstall}, not both.
+	 * Variant of {@link #modules(Module...)} with a {@link List}.
 	 * @see #modules(Module...)
+	 * @see #modules(Consumer)
 	 * @see com.fasterxml.jackson.databind.Module
 	 */
 	public Jackson2ObjectMapperBuilder modules(List<Module> modules) {
@@ -556,6 +550,22 @@ public Jackson2ObjectMapperBuilder modules(List<Module> modules) {
 		return this;
 	}
 
+	/**
+	 * Variant of {@link #modules(Module...)} with a {@link Consumer} for full
+	 * control over the underlying list of modules.
+	 * @since 6.0
+	 * @see #modules(Module...)
+	 * @see #modules(List)
+	 * @see com.fasterxml.jackson.databind.Module
+	 */
+	public Jackson2ObjectMapperBuilder modules(Consumer<List<Module>> consumer) {
+		this.modules = (this.modules != null ? this.modules : new ArrayList<>());
+		this.findModulesViaServiceLoader = false;
+		this.findWellKnownModules = false;
+		consumer.accept(this.modules);
+		return this;
+	}
+
 	/**
 	 * Specify one or more modules to be registered with the {@link ObjectMapper}.
 	 * <p>Multiple invocations are not additive, the last one defines the modules
@@ -566,6 +576,7 @@ public Jackson2ObjectMapperBuilder modules(List<Module> modules) {
 	 * allowing to eventually override their configuration.
 	 * <p>Specify either this or {@link #modules(Module...)}, not both.
 	 * @since 4.1.5
+	 * @see #modulesToInstall(Consumer)
 	 * @see #modulesToInstall(Class...)
 	 * @see com.fasterxml.jackson.databind.Module
 	 */
@@ -575,6 +586,21 @@ public Jackson2ObjectMapperBuilder modulesToInstall(Module... modules) {
 		return this;
 	}
 
+	/**
+	 * Variant of {@link #modulesToInstall(Module...)} with a {@link Consumer}
+	 * for full control over the underlying list of modules.
+	 * @since 6.0
+	 * @see #modulesToInstall(Module...)
+	 * @see #modulesToInstall(Class...)
+	 * @see com.fasterxml.jackson.databind.Module
+	 */
+	public Jackson2ObjectMapperBuilder modulesToInstall(Consumer<List<Module>> consumer) {
+		this.modules = (this.modules != null ? this.modules : new ArrayList<>());
+		this.findWellKnownModules = true;
+		consumer.accept(this.modules);
+		return this;
+	}
+
 	/**
 	 * Specify one or more modules by class to be registered with
 	 * the {@link ObjectMapper}.
@@ -586,6 +612,7 @@ public Jackson2ObjectMapperBuilder modulesToInstall(Module... modules) {
 	 * allowing to eventually override their configuration.
 	 * <p>Specify either this or {@link #modules(Module...)}, not both.
 	 * @see #modulesToInstall(Module...)
+	 * @see #modulesToInstall(Consumer)
 	 * @see com.fasterxml.jackson.databind.Module
 	 */
 	@SafeVarargs

spring-web/src/test/java/org/springframework/http/converter/json/Jackson2ObjectMapperBuilderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -241,6 +241,16 @@ void modules() {
 		assertThat(serializers.findSerializer(null, SimpleType.construct(Integer.class), null)).isSameAs(serializer1);
 	}
 
+	@Test
+	void modulesWithConsumer() {
+		NumberSerializer serializer1 = new NumberSerializer(Integer.class);
+		SimpleModule module = new SimpleModule();
+		module.addSerializer(Integer.class, serializer1);
+		ObjectMapper objectMapper = Jackson2ObjectMapperBuilder.json().modules(list -> list.add(module) ).build();
+		Serializers serializers = getSerializerFactoryConfig(objectMapper).serializers().iterator().next();
+		assertThat(serializers.findSerializer(null, SimpleType.construct(Integer.class), null)).isSameAs(serializer1);
+	}
+
 	@Test
 	void modulesToInstallByClass() {
 		ObjectMapper objectMapper = Jackson2ObjectMapperBuilder.json()
@@ -259,6 +269,15 @@ void modulesToInstallByInstance() {
 		assertThat(serializers.findSerializer(null, SimpleType.construct(Integer.class), null).getClass()).isSameAs(CustomIntegerSerializer.class);
 	}
 
+	@Test
+	void modulesToInstallWithConsumer() {
+		ObjectMapper objectMapper = Jackson2ObjectMapperBuilder.json()
+				.modulesToInstall(list -> list.add(new CustomIntegerModule()))
+				.build();
+		Serializers serializers = getSerializerFactoryConfig(objectMapper).serializers().iterator().next();
+		assertThat(serializers.findSerializer(null, SimpleType.construct(Integer.class), null).getClass()).isSameAs(CustomIntegerSerializer.class);
+	}
+
 	@Test
 	void wellKnownModules() throws JsonProcessingException, UnsupportedEncodingException {
 		ObjectMapper objectMapper = Jackson2ObjectMapperBuilder.json().build();