Add Jackson2Tester support

See gh-47688

core/spring-boot-test/build.gradle

@@ -27,7 +27,7 @@ dependencies {
 	api(project(":core:spring-boot"))
 	api("org.springframework:spring-test")
 
-	optional("tools.jackson.core:jackson-databind")
+	optional("com.fasterxml.jackson.core:jackson-databind")
 	optional("com.google.code.gson:gson")
 	optional("com.jayway.jsonpath:json-path")
 	optional("jakarta.json.bind:jakarta.json.bind-api")
@@ -45,6 +45,7 @@ dependencies {
 	optional("org.seleniumhq.selenium:selenium-api")
 	optional("org.skyscreamer:jsonassert")
 	optional("org.springframework:spring-web")
+	optional("tools.jackson.core:jackson-databind")
 
 	testImplementation(project(":test-support:spring-boot-test-support"))
 	testImplementation("ch.qos.logback:logback-classic")

core/spring-boot-test/src/main/java/org/springframework/boot/test/json/Jackson2Tester.java

@@ -0,0 +1,207 @@
+/*
+ * Copyright 2012-present 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.test.json;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.Reader;
+
+import com.fasterxml.jackson.databind.JavaType;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectReader;
+import com.fasterxml.jackson.databind.ObjectWriter;
+import com.jayway.jsonpath.Configuration;
+import com.jayway.jsonpath.spi.json.JacksonJsonProvider;
+import com.jayway.jsonpath.spi.mapper.JacksonMappingProvider;
+import org.jspecify.annotations.Nullable;
+
+import org.springframework.beans.factory.ObjectFactory;
+import org.springframework.core.ResolvableType;
+import org.springframework.util.Assert;
+
+/**
+ * AssertJ based JSON tester backed by Jackson 2. Usually instantiated via
+ * {@link #initFields(Object, ObjectMapper)}, for example: <pre class="code">
+ * public class ExampleObjectJsonTests {
+ *
+ *     private Jackson2Tester&lt;ExampleObject&gt; json;
+ *
+ *     &#064;Before
+ *     public void setup() {
+ *         ObjectMapper objectMapper = new ObjectMapper();
+ *         Jackson2Tester.initFields(this, objectMapper);
+ *     }
+ *
+ *     &#064;Test
+ *     public void testWriteJson() throws IOException {
+ *         ExampleObject object = //...
+ *         assertThat(json.write(object)).isEqualToJson("expected.json");
+ *     }
+ *
+ * }
+ * </pre>
+ *
+ * See {@link AbstractJsonMarshalTester} for more details.
+ *
+ * @param <T> the type under test
+ * @author Phillip Webb
+ * @author Madhura Bhave
+ * @author Diego Berrueta
+ * @since 4.0.0
+ * @deprecated since 4.0.0 for removal in 4.2.0 in favor of Jackson 3.
+ */
+@Deprecated(since = "4.0.0", forRemoval = true)
+public class Jackson2Tester<T> extends AbstractJsonMarshalTester<T> {
+
+	private final ObjectMapper objectMapper;
+
+	private @Nullable Class<?> view;
+
+	/**
+	 * Create a new {@link Jackson2Tester} instance.
+	 * @param objectMapper the Jackson object mapper
+	 */
+	protected Jackson2Tester(ObjectMapper objectMapper) {
+		Assert.notNull(objectMapper, "'objectMapper' must not be null");
+		this.objectMapper = objectMapper;
+	}
+
+	/**
+	 * Create a new {@link Jackson2Tester} instance.
+	 * @param resourceLoadClass the source class used to load resources
+	 * @param type the type under test
+	 * @param objectMapper the Jackson object mapper
+	 */
+	public Jackson2Tester(Class<?> resourceLoadClass, ResolvableType type, ObjectMapper objectMapper) {
+		this(resourceLoadClass, type, objectMapper, null);
+	}
+
+	/**
+	 * Create a new {@link Jackson2Tester} instance.
+	 * @param resourceLoadClass the source class used to load resources
+	 * @param type the type under test
+	 * @param objectMapper the Jackson object mapper
+	 * @param view the JSON view
+	 */
+	public Jackson2Tester(Class<?> resourceLoadClass, ResolvableType type, ObjectMapper objectMapper,
+			@Nullable Class<?> view) {
+		super(resourceLoadClass, type);
+		Assert.notNull(objectMapper, "'objectMapper' must not be null");
+		this.objectMapper = objectMapper;
+		this.view = view;
+	}
+
+	@Override
+	protected JsonContent<T> getJsonContent(String json) {
+		Configuration configuration = Configuration.builder()
+			.jsonProvider(new JacksonJsonProvider(this.objectMapper))
+			.mappingProvider(new JacksonMappingProvider(this.objectMapper))
+			.build();
+		Class<?> resourceLoadClass = getResourceLoadClass();
+		Assert.state(resourceLoadClass != null, "'resourceLoadClass' must not be null");
+		return new JsonContent<>(resourceLoadClass, getType(), json, configuration);
+	}
+
+	@Override
+	protected T readObject(InputStream inputStream, ResolvableType type) throws IOException {
+		return getObjectReader(type).readValue(inputStream);
+	}
+
+	@Override
+	protected T readObject(Reader reader, ResolvableType type) throws IOException {
+		return getObjectReader(type).readValue(reader);
+	}
+
+	private ObjectReader getObjectReader(ResolvableType type) {
+		ObjectReader objectReader = this.objectMapper.readerFor(getType(type));
+		if (this.view != null) {
+			return objectReader.withView(this.view);
+		}
+		return objectReader;
+	}
+
+	@Override
+	protected String writeObject(T value, ResolvableType type) throws IOException {
+		return getObjectWriter(type).writeValueAsString(value);
+	}
+
+	private ObjectWriter getObjectWriter(ResolvableType type) {
+		ObjectWriter objectWriter = this.objectMapper.writerFor(getType(type));
+		if (this.view != null) {
+			return objectWriter.withView(this.view);
+		}
+		return objectWriter;
+	}
+
+	private JavaType getType(ResolvableType type) {
+		return this.objectMapper.constructType(type.getType());
+	}
+
+	/**
+	 * Utility method to initialize {@link Jackson2Tester} fields. See
+	 * {@link Jackson2Tester class-level documentation} for example usage.
+	 * @param testInstance the test instance
+	 * @param objectMapper the JSON mapper
+	 * @see #initFields(Object, ObjectMapper)
+	 */
+	public static void initFields(Object testInstance, ObjectMapper objectMapper) {
+		new Jackson2FieldInitializer().initFields(testInstance, objectMapper);
+	}
+
+	/**
+	 * Utility method to initialize {@link Jackson2Tester} fields. See
+	 * {@link Jackson2Tester class-level documentation} for example usage.
+	 * @param testInstance the test instance
+	 * @param objectMapperFactory a factory to create the object mapper
+	 * @see #initFields(Object, ObjectMapper)
+	 */
+	public static void initFields(Object testInstance, ObjectFactory<ObjectMapper> objectMapperFactory) {
+		new Jackson2FieldInitializer().initFields(testInstance, objectMapperFactory);
+	}
+
+	/**
+	 * Returns a new instance of {@link Jackson2Tester} with the view that should be used
+	 * for json serialization/deserialization.
+	 * @param view the view class
+	 * @return the new instance
+	 */
+	public Jackson2Tester<T> forView(Class<?> view) {
+		Class<?> resourceLoadClass = getResourceLoadClass();
+		ResolvableType type = getType();
+		Assert.state(resourceLoadClass != null, "'resourceLoadClass' must not be null");
+		Assert.state(type != null, "'type' must not be null");
+		return new Jackson2Tester<>(resourceLoadClass, type, this.objectMapper, view);
+	}
+
+	/**
+	 * {@link FieldInitializer} for Jackson.
+	 */
+	private static class Jackson2FieldInitializer extends FieldInitializer<ObjectMapper> {
+
+		protected Jackson2FieldInitializer() {
+			super(Jackson2Tester.class);
+		}
+
+		@Override
+		protected AbstractJsonMarshalTester<Object> createTester(Class<?> resourceLoadClass, ResolvableType type,
+				ObjectMapper marshaller) {
+			return new Jackson2Tester<>(resourceLoadClass, type, marshaller);
+		}
+
+	}
+
+}

core/spring-boot-test/src/main/java/org/springframework/boot/test/json/JacksonTester.java

@@ -103,6 +103,14 @@ public class JacksonTester<T> extends AbstractJsonMarshalTester<T> {
 		this(resourceLoadClass, type, jsonMapper, null);
 	}
 
+	/**
+	 * Create a new {@link JacksonTester} instance.
+	 * @param resourceLoadClass the source class used to load resources
+	 * @param type the type under test
+	 * @param jsonMapper the Jackson JSON mapper
+	 * @param view the JSON view
+	 * @since 4.0.0
+	 */
 	public JacksonTester(Class<?> resourceLoadClass, ResolvableType type, JsonMapper jsonMapper,
 			@Nullable Class<?> view) {
 		super(resourceLoadClass, type);

core/spring-boot-test/src/test/java/org/springframework/boot/test/json/Jackson2TesterTests.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2012-present 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.test.json;
+
+import java.util.List;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.jspecify.annotations.Nullable;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.core.ResolvableType;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+
+/**
+ * Tests for {@link Jackson2Tester}.
+ *
+ * @author Phillip Webb
+ * @deprecated since 4.0.0 for removal in 4.2.0 in favor of JacksonTesterTests
+ */
+@Deprecated(since = "4.0.0", forRemoval = true)
+@SuppressWarnings("removal")
+class Jackson2TesterTests extends AbstractJsonMarshalTesterTests {
+
+	@Test
+	@SuppressWarnings("NullAway") // Test null check
+	void initFieldsWhenTestIsNullShouldThrowException() {
+		assertThatIllegalArgumentException().isThrownBy(() -> Jackson2Tester.initFields(null, new ObjectMapper()))
+			.withMessageContaining("'testInstance' must not be null");
+	}
+
+	@Test
+	@SuppressWarnings("NullAway") // Test null check
+	void initFieldsWhenMarshallerIsNullShouldThrowException() {
+		assertThatIllegalArgumentException()
+			.isThrownBy(() -> Jackson2Tester.initFields(new InitFieldsTestClass(), (ObjectMapper) null))
+			.withMessageContaining("'marshaller' must not be null");
+	}
+
+	@Test
+	void initFieldsShouldSetNullFields() {
+		InitFieldsTestClass test = new InitFieldsTestClass();
+		assertThat(test.test).isNull();
+		assertThat(test.base).isNull();
+		Jackson2Tester.initFields(test, new ObjectMapper());
+		assertThat(test.test).isNotNull();
+		assertThat(test.base).isNotNull();
+		ResolvableType type = test.test.getType();
+		assertThat(type).isNotNull();
+		assertThat(type.resolve()).isEqualTo(List.class);
+		assertThat(type.resolveGeneric()).isEqualTo(ExampleObject.class);
+	}
+
+	@Override
+	protected AbstractJsonMarshalTester<Object> createTester(Class<?> resourceLoadClass, ResolvableType type) {
+		return new org.springframework.boot.test.json.Jackson2Tester<>(resourceLoadClass, type, new ObjectMapper());
+	}
+
+	abstract static class InitFieldsBaseClass {
+
+		public org.springframework.boot.test.json.@Nullable Jackson2Tester<ExampleObject> base;
+
+		public org.springframework.boot.test.json.Jackson2Tester<ExampleObject> baseSet = new org.springframework.boot.test.json.Jackson2Tester<>(
+				InitFieldsBaseClass.class, ResolvableType.forClass(ExampleObject.class), new ObjectMapper());
+
+	}
+
+	static class InitFieldsTestClass extends InitFieldsBaseClass {
+
+		public org.springframework.boot.test.json.@Nullable Jackson2Tester<List<ExampleObject>> test;
+
+		public org.springframework.boot.test.json.Jackson2Tester<ExampleObject> testSet = new org.springframework.boot.test.json.Jackson2Tester<>(
+				InitFieldsBaseClass.class, ResolvableType.forClass(ExampleObject.class), new ObjectMapper());
+
+	}
+
+}

module/spring-boot-jackson2/src/main/java/org/springframework/boot/jackson2/autoconfigure/Jackson2TesterAutoConfiguration.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2012-present 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.jackson2.autoconfigure;
+
+import com.fasterxml.jackson.databind.json.JsonMapper;
+
+import org.springframework.beans.factory.FactoryBean;
+import org.springframework.beans.factory.config.ConfigurableBeanFactory;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.test.autoconfigure.TestAutoConfiguration;
+import org.springframework.boot.test.autoconfigure.json.ConditionalOnJsonTesters;
+import org.springframework.boot.test.autoconfigure.json.JsonMarshalTesterRuntimeHints;
+import org.springframework.boot.test.autoconfigure.json.JsonTesterFactoryBean;
+import org.springframework.boot.test.json.GsonTester;
+import org.springframework.boot.test.json.JacksonTester;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ImportRuntimeHints;
+import org.springframework.context.annotation.Scope;
+
+/**
+ * {@link EnableAutoConfiguration Auto-configuration} for {@link GsonTester}.
+ *
+ * @author Phjllip Webb
+ * @deprecated since 4.0.0 for removal in 4.2.0 in favor of Jackson 3.
+ */
+@Deprecated(since = "4.0.0", forRemoval = true)
+@TestAutoConfiguration(after = Jackson2AutoConfiguration.class)
+@ConditionalOnJsonTesters
+@SuppressWarnings("removal")
+final class Jackson2TesterAutoConfiguration {
+
+	@Bean
+	@Scope(ConfigurableBeanFactory.SCOPE_PROTOTYPE)
+	@ConditionalOnBean(JsonMapper.class)
+	@ImportRuntimeHints(Jackson2TesterRuntimeHints.class)
+	FactoryBean<JacksonTester<?>> jacksonTesterFactoryBean(JsonMapper mapper) {
+		return new JsonTesterFactoryBean<>(JacksonTester.class, mapper);
+	}
+
+	static class Jackson2TesterRuntimeHints extends JsonMarshalTesterRuntimeHints {
+
+		Jackson2TesterRuntimeHints() {
+			super(JacksonTester.class);
+		}
+
+	}
+
+}

module/spring-boot-jackson2/src/main/resources/META-INF/spring/org.springframework.boot.test.autoconfigure.json.AutoConfigureJson.imports

@@ -0,0 +1 @@
+org.springframework.boot.jackson.autoconfigure.Jackson2AutoConfiguration

module/spring-boot-jackson2/src/main/resources/META-INF/spring/org.springframework.boot.test.autoconfigure.json.AutoConfigureJsonTesters.imports

@@ -0,0 +1 @@
+org.springframework.boot.jackson.autoconfigure.Jackson2TesterAutoConfiguration

module/spring-boot-jackson2/src/main/resources/META-INF/spring/org.springframework.boot.test.autoconfigure.json.JsonTest.includes

@@ -0,0 +1,2 @@
+org.springframework.boot.jackson2.JsonComponent
+com.fasterxml.jackson.databind.Module