Support date conversion format for java.time types

Prior to this change, the Spring MVC auto-configuration would add a new
formatter to convert `java.util.Date` to/from `String` using the
configured configuration property `spring.mvc.date-format`.

This commit adds a new `WebConversionService` class that registers
date formatters with a custom date format, or register the default ones
if no custom configuration is provided.
This avoids duplicating equivalent formatters in the registry.

With this change, date types from `java.util`, `org.joda.time` and
`java.time` are now all supported.

This commit also replicates this feature for WebFlux applications by
adding a new `spring.webflux.date-format` configuration property.

Closes gh-5523
Closes gh-11402

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/format/WebConversionService.java

+/*
+ * Copyright 2012-2017 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
+ *
+ *      http://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.autoconfigure.web.format;
+
+import java.time.format.DateTimeFormatter;
+import java.time.format.ResolverStyle;
+
+import org.joda.time.format.DateTimeFormatterBuilder;
+
+import org.springframework.format.datetime.DateFormatter;
+import org.springframework.format.datetime.DateFormatterRegistrar;
+import org.springframework.format.datetime.joda.JodaTimeFormatterRegistrar;
+import org.springframework.format.datetime.standard.DateTimeFormatterRegistrar;
+import org.springframework.format.number.NumberFormatAnnotationFormatterFactory;
+import org.springframework.format.number.money.CurrencyUnitFormatter;
+import org.springframework.format.number.money.Jsr354NumberFormatAnnotationFormatterFactory;
+import org.springframework.format.number.money.MonetaryAmountFormatter;
+import org.springframework.format.support.DefaultFormattingConversionService;
+import org.springframework.util.ClassUtils;
+import org.springframework.util.StringUtils;
+
+/**
+ * {@link org.springframework.format.support.FormattingConversionService} dedicated
+ * to web applications for formatting and converting values to/from the web.
+ *
+ * <p>This service replaces the default implementations provided by
+ * {@link org.springframework.web.servlet.config.annotation.EnableWebMvc}
+ * and {@link org.springframework.web.reactive.config.EnableWebFlux}.
+ *
+ * @author Brian Clozel
+ * @since 2.0.0
+ */
+public class WebConversionService extends DefaultFormattingConversionService {
+
+	private static final boolean jsr354Present = ClassUtils
+			.isPresent("javax.money.MonetaryAmount", WebConversionService.class.getClassLoader());
+
+	private static final boolean jodaTimePresent = ClassUtils
+			.isPresent("org.joda.time.LocalDate", WebConversionService.class.getClassLoader());
+
+	private String dateFormat;
+
+	/**
+	 * Create a new WebConversionService that configures formatters with the provided date format,
+	 * or register the default ones if no custom format is provided.
+	 * @param dateFormat the custom date format to use for date conversions
+	 */
+	public WebConversionService(String dateFormat) {
+		super(false);
+		if (StringUtils.hasText(dateFormat)) {
+			this.dateFormat = dateFormat;
+			addFormatters();
+		}
+		else {
+			addDefaultFormatters(this);
+		}
+	}
+
+
+	private void addFormatters() {
+		addFormatterForFieldAnnotation(new NumberFormatAnnotationFormatterFactory());
+		if (jsr354Present) {
+			addFormatter(new CurrencyUnitFormatter());
+			addFormatter(new MonetaryAmountFormatter());
+			addFormatterForFieldAnnotation(new Jsr354NumberFormatAnnotationFormatterFactory());
+		}
+		registerJsr310();
+		if (jodaTimePresent) {
+			registerJodaTime();
+		}
+		registerJavaDate();
+	}
+
+	private void registerJsr310() {
+		DateTimeFormatterRegistrar dateTime = new DateTimeFormatterRegistrar();
+		if (this.dateFormat != null) {
+			DateTimeFormatter dateTimeFormatter = DateTimeFormatter
+					.ofPattern(this.dateFormat)
+					.withResolverStyle(ResolverStyle.STRICT);
+			dateTime.setDateFormatter(dateTimeFormatter);
+		}
+		dateTime.registerFormatters(this);
+	}
+
+	private void registerJodaTime() {
+		JodaTimeFormatterRegistrar jodaTime = new JodaTimeFormatterRegistrar();
+		if (this.dateFormat != null) {
+			org.joda.time.format.DateTimeFormatter dateTimeFormatter = new DateTimeFormatterBuilder()
+					.appendPattern(this.dateFormat)
+					.toFormatter();
+			jodaTime.setDateFormatter(dateTimeFormatter);
+		}
+		jodaTime.registerFormatters(this);
+	}
+
+	private void registerJavaDate() {
+		DateFormatterRegistrar dateFormatterRegistrar = new DateFormatterRegistrar();
+		if (this.dateFormat != null) {
+			DateFormatter dateFormatter = new DateFormatter(this.dateFormat);
+			dateFormatterRegistrar.setFormatter(dateFormatter);
+		}
+		dateFormatterRegistrar.registerFormatters(this);
+	}
+}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/reactive/WebFluxAutoConfiguration.java

@@ -34,9 +34,11 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
 import org.springframework.boot.autoconfigure.http.codec.CodecsAutoConfiguration;
+import org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration;
 import org.springframework.boot.autoconfigure.validation.ValidatorAdapter;
 import org.springframework.boot.autoconfigure.web.ConditionalOnEnabledResourceChain;
 import org.springframework.boot.autoconfigure.web.ResourceProperties;
+import org.springframework.boot.autoconfigure.web.format.WebConversionService;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.boot.web.codec.CodecCustomizer;
 import org.springframework.context.annotation.Bean;
@@ -48,6 +50,7 @@ import org.springframework.core.convert.converter.Converter;
 import org.springframework.core.convert.converter.GenericConverter;
 import org.springframework.format.Formatter;
 import org.springframework.format.FormatterRegistry;
+import org.springframework.format.support.FormattingConversionService;
 import org.springframework.http.CacheControl;
 import org.springframework.http.codec.ServerCodecConfigurer;
 import org.springframework.util.ClassUtils;
@@ -84,7 +87,7 @@ import org.springframework.web.reactive.result.view.ViewResolver;
 @ConditionalOnClass(WebFluxConfigurer.class)
 @ConditionalOnMissingBean({ WebFluxConfigurationSupport.class })
 @AutoConfigureAfter({ ReactiveWebServerAutoConfiguration.class,
-		CodecsAutoConfiguration.class })
+		CodecsAutoConfiguration.class, ValidationAutoConfiguration.class })
 @AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE + 10)
 public class WebFluxAutoConfiguration {
 
@@ -211,8 +214,22 @@ public class WebFluxAutoConfiguration {
 	public static class EnableWebFluxConfiguration
 			extends DelegatingWebFluxConfiguration {
 
+		private final WebFluxProperties webFluxProperties;
+
+		public EnableWebFluxConfiguration(WebFluxProperties webFluxProperties) {
+			this.webFluxProperties = webFluxProperties;
+		}
+
+		@Bean
 		@Override
+		public FormattingConversionService webFluxConversionService() {
+			WebConversionService conversionService = new WebConversionService(this.webFluxProperties.getDateFormat());
+			addFormatters(conversionService);
+			return conversionService;
+		}
+
 		@Bean
+		@Override
 		public Validator webFluxValidator() {
 			if (!ClassUtils.isPresent("javax.validation.Validator",
 					getClass().getClassLoader())) {

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/reactive/WebFluxProperties.java

@@ -27,11 +27,24 @@ import org.springframework.boot.context.properties.ConfigurationProperties;
 @ConfigurationProperties(prefix = "spring.webflux")
 public class WebFluxProperties {
 
+	/**
+	 * Date format to use. For instance, "dd/MM/yyyy".
+	 */
+	private String dateFormat;
+
 	/**
 	 * Path pattern used for static resources.
 	 */
 	private String staticPathPattern = "/**";
 
+	public String getDateFormat() {
+		return this.dateFormat;
+	}
+
+	public void setDateFormat(String dateFormat) {
+		this.dateFormat = dateFormat;
+	}
+
 	public String getStaticPathPattern() {
 		return this.staticPathPattern;
 	}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration.java

@@ -21,7 +21,6 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.Date;
 import java.util.List;
 import java.util.ListIterator;
 import java.util.Map;
@@ -54,6 +53,7 @@ import org.springframework.boot.autoconfigure.validation.ValidatorAdapter;
 import org.springframework.boot.autoconfigure.web.ConditionalOnEnabledResourceChain;
 import org.springframework.boot.autoconfigure.web.ResourceProperties;
 import org.springframework.boot.autoconfigure.web.ResourceProperties.Strategy;
+import org.springframework.boot.autoconfigure.web.format.WebConversionService;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.boot.web.servlet.filter.OrderedHiddenHttpMethodFilter;
 import org.springframework.boot.web.servlet.filter.OrderedHttpPutFormContentFilter;
@@ -73,7 +73,7 @@ import org.springframework.core.io.Resource;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.format.Formatter;
 import org.springframework.format.FormatterRegistry;
-import org.springframework.format.datetime.DateFormatter;
+import org.springframework.format.support.FormattingConversionService;
 import org.springframework.http.CacheControl;
 import org.springframework.http.MediaType;
 import org.springframework.http.converter.HttpMessageConverter;
@@ -266,12 +266,6 @@ public class WebMvcAutoConfiguration {
 			return localeResolver;
 		}
 
-		@Bean
-		@ConditionalOnProperty(prefix = "spring.mvc", name = "date-format")
-		public Formatter<Date> dateFormatter() {
-			return new DateFormatter(this.mvcProperties.getDateFormat());
-		}
-
 		@Override
 		public MessageCodesResolver getMessageCodesResolver() {
 			if (this.mvcProperties.getMessageCodesResolverFormat() != null) {
@@ -478,6 +472,14 @@ public class WebMvcAutoConfiguration {
 			return super.requestMappingHandlerMapping();
 		}
 
+		@Bean
+		@Override
+		public FormattingConversionService mvcConversionService() {
+			WebConversionService conversionService = new WebConversionService(this.mvcProperties.getDateFormat());
+			addFormatters(conversionService);
+			return conversionService;
+		}
+
 		@Bean
 		@Override
 		public Validator mvcValidator() {

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/format/WebConversionServiceTests.java

+/*
+ * Copyright 2012-2017 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
+ *
+ *      http://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.autoconfigure.web.format;
+
+import java.util.Date;
+
+import org.joda.time.DateTime;
+import org.joda.time.LocalDate;
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link WebConversionService}.
+ *
+ * @author Brian Clozel
+ */
+public class WebConversionServiceTests {
+
+	@Test
+	public void customDateFormat() {
+		WebConversionService conversionService = new WebConversionService("dd*MM*yyyy");
+
+		Date date = new DateTime(2018, 1, 1, 20, 30).toDate();
+		assertThat(conversionService.convert(date, String.class))
+				.isEqualTo("01*01*2018");
+
+		LocalDate jodaDate = LocalDate.fromDateFields(date);
+		assertThat(conversionService.convert(jodaDate, String.class))
+				.isEqualTo("01*01*2018");
+
+		java.time.LocalDate localDate = java.time.LocalDate.of(2018, 1, 1);
+		assertThat(conversionService.convert(localDate, String.class))
+				.isEqualTo("01*01*2018");
+	}
+}

spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -465,7 +465,8 @@ content into your application. Rather, pick only the properties that you need.
 	spring.thymeleaf.template-resolver-order= # Order of the template resolver in the chain.
 	spring.thymeleaf.view-names= # Comma-separated list of view names that can be resolved.
 
-	# SPRING WEB FLUX ({sc-spring-boot-autoconfigure}/web/reactive/WebFluxProperties.{sc-ext}[WebFluxProperties])
+	# SPRING WEBFLUX ({sc-spring-boot-autoconfigure}/web/reactive/WebFluxProperties.{sc-ext}[WebFluxProperties])
+	spring.webflux.date-format= # Date format to use. For instance, `dd/MM/yyyy`.
 	spring.webflux.static-path-pattern=/** # Path pattern used for static resources.
 
 	# SPRING WEB SERVICES ({sc-spring-boot-autoconfigure}/webservices/WebServicesProperties.{sc-ext}[WebServicesProperties])