Efficient ISO_LOCAL_* variants for printing LocalDate/LocalTime/LocalDateTime

Issue: SPR-14958

spring-context/src/main/java/org/springframework/format/datetime/standard/DateTimeFormatterRegistrar.java

@@ -29,7 +29,7 @@ import java.time.YearMonth;
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
 import java.time.format.FormatStyle;
-import java.util.HashMap;
+import java.util.EnumMap;
 import java.util.Map;
 
 import org.springframework.format.FormatterRegistrar;
@@ -56,18 +56,17 @@ public class DateTimeFormatterRegistrar implements FormatterRegistrar {
 
 
 	/**
-	 * User defined formatters.
+	 * User-defined formatters.
 	 */
-	private final Map<Type, DateTimeFormatter> formatters = new HashMap<>();
+	private final Map<Type, DateTimeFormatter> formatters = new EnumMap<>(Type.class);
 
 	/**
 	 * Factories used when specific formatters have not been specified.
 	 */
-	private final Map<Type, DateTimeFormatterFactory> factories;
+	private final Map<Type, DateTimeFormatterFactory> factories = new EnumMap<>(Type.class);
 
 
 	public DateTimeFormatterRegistrar() {
-		this.factories = new HashMap<>();
 		for (Type type : Type.values()) {
 			this.factories.put(type, new DateTimeFormatterFactory());
 		}
@@ -155,33 +154,38 @@ public class DateTimeFormatterRegistrar implements FormatterRegistrar {
 	public void registerFormatters(FormatterRegistry registry) {
 		DateTimeConverters.registerConverters(registry);
 
-		DateTimeFormatter dateFormatter = getFormatter(Type.DATE);
-		DateTimeFormatter timeFormatter = getFormatter(Type.TIME);
-		DateTimeFormatter dateTimeFormatter = getFormatter(Type.DATE_TIME);
+		DateTimeFormatter df = getFormatter(Type.DATE);
+		DateTimeFormatter tf = getFormatter(Type.TIME);
+		DateTimeFormatter dtf = getFormatter(Type.DATE_TIME);
+
+		// Efficient ISO_LOCAL_* variants for printing since they are twice as fast...
 
 		registry.addFormatterForFieldType(LocalDate.class,
-				new TemporalAccessorPrinter(dateFormatter),
-				new TemporalAccessorParser(LocalDate.class, dateFormatter));
+				new TemporalAccessorPrinter(
+						df == DateTimeFormatter.ISO_DATE ? DateTimeFormatter.ISO_LOCAL_DATE : df),
+				new TemporalAccessorParser(LocalDate.class, df));
 
 		registry.addFormatterForFieldType(LocalTime.class,
-				new TemporalAccessorPrinter(timeFormatter),
-				new TemporalAccessorParser(LocalTime.class, timeFormatter));
+				new TemporalAccessorPrinter(
+						tf == DateTimeFormatter.ISO_TIME ? DateTimeFormatter.ISO_LOCAL_TIME : tf),
+				new TemporalAccessorParser(LocalTime.class, tf));
 
 		registry.addFormatterForFieldType(LocalDateTime.class,
-				new TemporalAccessorPrinter(dateTimeFormatter),
-				new TemporalAccessorParser(LocalDateTime.class, dateTimeFormatter));
+				new TemporalAccessorPrinter(
+						dtf == DateTimeFormatter.ISO_DATE_TIME ? DateTimeFormatter.ISO_LOCAL_DATE_TIME : dtf),
+				new TemporalAccessorParser(LocalDateTime.class, dtf));
 
 		registry.addFormatterForFieldType(ZonedDateTime.class,
-				new TemporalAccessorPrinter(dateTimeFormatter),
-				new TemporalAccessorParser(ZonedDateTime.class, dateTimeFormatter));
+				new TemporalAccessorPrinter(dtf),
+				new TemporalAccessorParser(ZonedDateTime.class, dtf));
 
 		registry.addFormatterForFieldType(OffsetDateTime.class,
-				new TemporalAccessorPrinter(dateTimeFormatter),
-				new TemporalAccessorParser(OffsetDateTime.class, dateTimeFormatter));
+				new TemporalAccessorPrinter(dtf),
+				new TemporalAccessorParser(OffsetDateTime.class, dtf));
 
 		registry.addFormatterForFieldType(OffsetTime.class,
-				new TemporalAccessorPrinter(timeFormatter),
-				new TemporalAccessorParser(OffsetTime.class, timeFormatter));
+				new TemporalAccessorPrinter(tf),
+				new TemporalAccessorParser(OffsetTime.class, tf));
 
 		registry.addFormatterForFieldType(Instant.class, new InstantFormatter());
 		registry.addFormatterForFieldType(Period.class, new PeriodFormatter());

spring-context/src/main/java/org/springframework/format/datetime/standard/Jsr310DateTimeFormatAnnotationFormatterFactory.java

@@ -68,6 +68,24 @@ public class Jsr310DateTimeFormatAnnotationFormatterFactory extends EmbeddedValu
 	@Override
 	public Printer<?> getPrinter(DateTimeFormat annotation, Class<?> fieldType) {
 		DateTimeFormatter formatter = getFormatter(annotation, fieldType);
+
+		// Efficient ISO_LOCAL_* variants for printing since they are twice as fast...
+		if (formatter == DateTimeFormatter.ISO_DATE) {
+			if (isLocal(fieldType)) {
+				formatter = DateTimeFormatter.ISO_LOCAL_DATE;
+			}
+		}
+		else if (formatter == DateTimeFormatter.ISO_TIME) {
+			if (isLocal(fieldType)) {
+				formatter = DateTimeFormatter.ISO_LOCAL_TIME;
+			}
+		}
+		else if (formatter == DateTimeFormatter.ISO_DATE_TIME) {
+			if (isLocal(fieldType)) {
+				formatter = DateTimeFormatter.ISO_LOCAL_DATE_TIME;
+			}
+		}
+
 		return new TemporalAccessorPrinter(formatter);
 	}
 
@@ -81,7 +99,7 @@ public class Jsr310DateTimeFormatAnnotationFormatterFactory extends EmbeddedValu
 	/**
 	 * Factory method used to create a {@link DateTimeFormatter}.
 	 * @param annotation the format annotation for the field
-	 * @param fieldType the type of field
+	 * @param fieldType the declared type of the field
 	 * @return a {@link DateTimeFormatter} instance
 	 */
 	protected DateTimeFormatter getFormatter(DateTimeFormat annotation, Class<?> fieldType) {
@@ -92,4 +110,8 @@ public class Jsr310DateTimeFormatAnnotationFormatterFactory extends EmbeddedValu
 		return factory.createDateTimeFormatter();
 	}
 
+	private boolean isLocal(Class<?> fieldType) {
+		return fieldType.getSimpleName().startsWith("Local");
+	}
+
 }

spring-context/src/test/java/org/springframework/format/datetime/standard/DateTimeFormattingTests.java

@@ -311,6 +311,15 @@ public class DateTimeFormattingTests {
 
 	@Test
 	public void testBindISOTime() {
+		MutablePropertyValues propertyValues = new MutablePropertyValues();
+		propertyValues.add("isoTime", "12:00:00");
+		binder.bind(propertyValues);
+		assertEquals(0, binder.getBindingResult().getErrorCount());
+		assertEquals("12:00:00", binder.getBindingResult().getFieldValue("isoTime"));
+	}
+
+	@Test
+	public void testBindISOTimeWithZone() {
 		MutablePropertyValues propertyValues = new MutablePropertyValues();
 		propertyValues.add("isoTime", "12:00:00.000-05:00");
 		binder.bind(propertyValues);
@@ -320,6 +329,15 @@ public class DateTimeFormattingTests {
 
 	@Test
 	public void testBindISODateTime() {
+		MutablePropertyValues propertyValues = new MutablePropertyValues();
+		propertyValues.add("isoDateTime", "2009-10-31T12:00:00");
+		binder.bind(propertyValues);
+		assertEquals(0, binder.getBindingResult().getErrorCount());
+		assertEquals("2009-10-31T12:00:00", binder.getBindingResult().getFieldValue("isoDateTime"));
+	}
+
+	@Test
+	public void testBindISODateTimeWithZone() {
 		MutablePropertyValues propertyValues = new MutablePropertyValues();
 		propertyValues.add("isoDateTime", "2009-10-31T12:00:00.000Z");
 		binder.bind(propertyValues);
@@ -386,29 +404,29 @@ public class DateTimeFormattingTests {
 
 		private LocalDate localDate;
 
-		@DateTimeFormat(style="M-")
+		@DateTimeFormat(style = "M-")
 		private LocalDate localDateAnnotated;
 
 		private LocalTime localTime;
 
-		@DateTimeFormat(style="-M")
+		@DateTimeFormat(style = "-M")
 		private LocalTime localTimeAnnotated;
 
 		private LocalDateTime localDateTime;
 
-		@DateTimeFormat(style="MM")
+		@DateTimeFormat(style = "MM")
 		private LocalDateTime localDateTimeAnnotated;
 
-		@DateTimeFormat(pattern="M/d/yy h:mm a")
+		@DateTimeFormat(pattern = "M/d/yy h:mm a")
 		private LocalDateTime dateTimeAnnotatedPattern;
 
-		@DateTimeFormat(iso=ISO.DATE)
+		@DateTimeFormat(iso = ISO.DATE)
 		private LocalDate isoDate;
 
-		@DateTimeFormat(iso=ISO.TIME)
+		@DateTimeFormat(iso = ISO.TIME)
 		private LocalTime isoTime;
 
-		@DateTimeFormat(iso=ISO.DATE_TIME)
+		@DateTimeFormat(iso = ISO.DATE_TIME)
 		private LocalDateTime isoDateTime;
 
 		private Instant instant;