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Add support for configuring Jackson's ConstructorDetector
Closes gh-27178
1 parent 60e57f7 commit 456d741

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

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@@ -34,13 +34,15 @@
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import com.fasterxml.jackson.databind.ObjectMapper;
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import com.fasterxml.jackson.databind.PropertyNamingStrategy;
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import com.fasterxml.jackson.databind.SerializationFeature;
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import com.fasterxml.jackson.databind.cfg.ConstructorDetector;
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import com.fasterxml.jackson.module.paramnames.ParameterNamesModule;
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import org.springframework.beans.BeanUtils;
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import org.springframework.beans.factory.BeanFactoryUtils;
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import org.springframework.beans.factory.ListableBeanFactory;
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import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
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import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
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import org.springframework.boot.autoconfigure.jackson.JacksonProperties.ConstructorDetectorStrategy;
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import org.springframework.boot.context.properties.EnableConfigurationProperties;
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import org.springframework.boot.jackson.JsonComponentModule;
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import org.springframework.context.ApplicationContext;
@@ -188,6 +190,7 @@ public void customize(Jackson2ObjectMapperBuilder builder) {
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configureModules(builder);
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configureLocale(builder);
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configureDefaultLeniency(builder);
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configureConstructorDetector(builder);
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}
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private void configureFeatures(Jackson2ObjectMapperBuilder builder, Map<?, Boolean> features) {
@@ -297,6 +300,27 @@ private void configureDefaultLeniency(Jackson2ObjectMapperBuilder builder) {
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}
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}
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private void configureConstructorDetector(Jackson2ObjectMapperBuilder builder) {
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ConstructorDetectorStrategy strategy = this.jacksonProperties.getConstructorDetector();
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if (strategy != null) {
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builder.postConfigurer((objectMapper) -> {
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switch (strategy) {
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case USE_PROPERTIES_BASED:
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objectMapper.setConstructorDetector(ConstructorDetector.USE_PROPERTIES_BASED);
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break;
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case USE_DELEGATING:
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objectMapper.setConstructorDetector(ConstructorDetector.USE_DELEGATING);
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break;
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case EXPLICIT_ONLY:
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objectMapper.setConstructorDetector(ConstructorDetector.EXPLICIT_ONLY);
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break;
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default:
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objectMapper.setConstructorDetector(ConstructorDetector.DEFAULT);
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}
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});
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}
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}
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private static <T> Collection<T> getBeans(ListableBeanFactory beanFactory, Class<T> type) {
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return BeanFactoryUtils.beansOfTypeIncludingAncestors(beanFactory, type).values();
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}

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

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@@ -97,6 +97,12 @@ public class JacksonProperties {
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*/
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private Boolean defaultLeniency;
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/**
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* Strategy to use to to auto-detect constructor, and in particular behavior with
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* single-argument constructors.
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*/
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private ConstructorDetectorStrategy constructorDetector;
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/**
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* Time zone used when formatting dates. For instance, "America/Los_Angeles" or
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* "GMT+10".
@@ -164,6 +170,14 @@ public void setDefaultLeniency(Boolean defaultLeniency) {
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this.defaultLeniency = defaultLeniency;
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}
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public ConstructorDetectorStrategy getConstructorDetector() {
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return this.constructorDetector;
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}
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public void setConstructorDetector(ConstructorDetectorStrategy constructorDetector) {
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this.constructorDetector = constructorDetector;
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}
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public TimeZone getTimeZone() {
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return this.timeZone;
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}
@@ -180,4 +194,29 @@ public void setLocale(Locale locale) {
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this.locale = locale;
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}
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public enum ConstructorDetectorStrategy {
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/**
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* Use heuristics to see if "properties" mode is to be used.
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*/
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DEFAULT,
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/**
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* Assume "properties" mode if not explicitly annotated otherwise.
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*/
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USE_PROPERTIES_BASED,
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/**
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* Assume "delegating" mode if not explicitly annotated otherwise.
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*/
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USE_DELEGATING,
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/**
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* Refuse to decide implicit mode and instead throw an InvalidDefinitionException
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* for ambiguous cases.
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*/
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EXPLICIT_ONLY;
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}
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}

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

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@@ -1048,6 +1048,10 @@
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"name": "spring.integration.jdbc.initialize-schema",
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"defaultValue": "embedded"
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},
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{
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"name": "spring.jackson.constructor-detector",
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"defaultValue": "default"
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},
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{
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"name": "spring.jackson.joda-date-time-format",
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"type": "java.lang.String",

‎spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jackson/Jackson211AutoConfigurationTests.java

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@@ -54,4 +54,25 @@ void customPropertyNamingStrategyClass() {
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});
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}
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// ConstructorDetector only available as of Jackson 2.12
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@Override
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void constructorDetectorWithNoStrategyUseDefault() {
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}
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@Override
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void constructorDetectorWithDefaultStrategy() {
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}
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@Override
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void constructorDetectorWithUsePropertiesBasedStrategy() {
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}
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@Override
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void constructorDetectorWithUseDelegatingStrategy() {
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}
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@Override
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void constructorDetectorWithExplicitOnlyStrategy() {
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}
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}

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

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@@ -41,6 +41,8 @@
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import com.fasterxml.jackson.databind.PropertyNamingStrategies.SnakeCaseStrategy;
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import com.fasterxml.jackson.databind.SerializationFeature;
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import com.fasterxml.jackson.databind.SerializerProvider;
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import com.fasterxml.jackson.databind.cfg.ConstructorDetector;
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import com.fasterxml.jackson.databind.cfg.ConstructorDetector.SingleArgConstructor;
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import com.fasterxml.jackson.databind.exc.InvalidFormatException;
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import com.fasterxml.jackson.databind.module.SimpleModule;
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import com.fasterxml.jackson.databind.util.StdDateFormat;
@@ -323,6 +325,62 @@ void disableDefaultLeniency() {
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});
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}
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@Test
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void constructorDetectorWithNoStrategyUseDefault() {
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this.contextRunner.run((context) -> {
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ObjectMapper mapper = context.getBean(ObjectMapper.class);
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ConstructorDetector cd = mapper.getDeserializationConfig().getConstructorDetector();
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assertThat(cd.singleArgMode()).isEqualTo(SingleArgConstructor.HEURISTIC);
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assertThat(cd.requireCtorAnnotation()).isFalse();
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assertThat(cd.allowJDKTypeConstructors()).isFalse();
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});
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}
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@Test
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void constructorDetectorWithDefaultStrategy() {
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this.contextRunner.withPropertyValues("spring.jackson.constructor-detector=default").run((context) -> {
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ObjectMapper mapper = context.getBean(ObjectMapper.class);
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ConstructorDetector cd = mapper.getDeserializationConfig().getConstructorDetector();
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assertThat(cd.singleArgMode()).isEqualTo(SingleArgConstructor.HEURISTIC);
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assertThat(cd.requireCtorAnnotation()).isFalse();
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assertThat(cd.allowJDKTypeConstructors()).isFalse();
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});
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}
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@Test
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void constructorDetectorWithUsePropertiesBasedStrategy() {
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this.contextRunner.withPropertyValues("spring.jackson.constructor-detector=use-properties-based")
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.run((context) -> {
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ObjectMapper mapper = context.getBean(ObjectMapper.class);
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ConstructorDetector cd = mapper.getDeserializationConfig().getConstructorDetector();
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assertThat(cd.singleArgMode()).isEqualTo(SingleArgConstructor.PROPERTIES);
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assertThat(cd.requireCtorAnnotation()).isFalse();
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assertThat(cd.allowJDKTypeConstructors()).isFalse();
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});
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}
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@Test
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void constructorDetectorWithUseDelegatingStrategy() {
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this.contextRunner.withPropertyValues("spring.jackson.constructor-detector=use-delegating").run((context) -> {
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ObjectMapper mapper = context.getBean(ObjectMapper.class);
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ConstructorDetector cd = mapper.getDeserializationConfig().getConstructorDetector();
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assertThat(cd.singleArgMode()).isEqualTo(SingleArgConstructor.DELEGATING);
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assertThat(cd.requireCtorAnnotation()).isFalse();
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assertThat(cd.allowJDKTypeConstructors()).isFalse();
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});
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}
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@Test
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void constructorDetectorWithExplicitOnlyStrategy() {
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this.contextRunner.withPropertyValues("spring.jackson.constructor-detector=explicit-only").run((context) -> {
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ObjectMapper mapper = context.getBean(ObjectMapper.class);
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ConstructorDetector cd = mapper.getDeserializationConfig().getConstructorDetector();
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assertThat(cd.singleArgMode()).isEqualTo(SingleArgConstructor.REQUIRE_MODE);
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assertThat(cd.requireCtorAnnotation()).isFalse();
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assertThat(cd.allowJDKTypeConstructors()).isFalse();
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});
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}
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@Test
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void additionalJacksonBuilderCustomization() {
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this.contextRunner.withUserConfiguration(ObjectMapperBuilderCustomConfig.class).run((context) -> {

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