Consistently strict parsing of date overflows (using java.time's strict resolution style)

Issue: SPR-13567

Author: jhoeller

spring-context/src/main/java/org/springframework/format/annotation/DateTimeFormat.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -75,6 +75,12 @@
 	 * <p>Defaults to empty String, indicating no custom pattern String has been specified.
 	 * Set this attribute when you wish to format your field in accordance with a custom
 	 * date time pattern not represented by a style or ISO format.
+	 * <p>Note: This pattern follows the original {@link java.text.SimpleDateFormat} style,
+	 * as also supported by Joda-Time, with strict parsing semantics towards overflows
+	 * (e.g. rejecting a Feb 29 value for a non-leap-year). As a consequence, 'yy'
+	 * characters indicate a year in the traditional style, not a "year-of-era" as in the
+	 * {@link java.time.format.DateTimeFormatter} specification (i.e. 'yy' turns into 'uu'
+	 * when going through that {@code DateTimeFormatter} with strict resolution mode).
 	 */
 	String pattern() default "";
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -18,6 +18,7 @@
 
 import java.time.format.DateTimeFormatter;
 import java.time.format.FormatStyle;
+import java.time.format.ResolverStyle;
 import java.util.TimeZone;
 
 import org.springframework.format.annotation.DateTimeFormat.ISO;
@@ -174,7 +175,11 @@ public DateTimeFormatter createDateTimeFormatter() {
 	public DateTimeFormatter createDateTimeFormatter(DateTimeFormatter fallbackFormatter) {
 		DateTimeFormatter dateTimeFormatter = null;
 		if (StringUtils.hasLength(this.pattern)) {
-			dateTimeFormatter = DateTimeFormatter.ofPattern(this.pattern);
+			// Using strict parsing to align with Joda-Time and standard DateFormat behavior:
+			// otherwise, an overflow like e.g. Feb 29 for a non-leap-year wouldn't get rejected.
+			// However, with strict parsing, a year digit needs to be specified as 'u'...
+			String patternToUse = this.pattern.replace("yy", "uu");
+			dateTimeFormatter = DateTimeFormatter.ofPattern(patternToUse).withResolverStyle(ResolverStyle.STRICT);
 		}
 		else if (this.iso != null && this.iso != ISO.NONE) {
 			switch (this.iso) {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -148,6 +148,14 @@ public void testBindDateAnnotatedPattern() {
 		assertEquals("10/31/09 1:05", binder.getBindingResult().getFieldValue("dateAnnotatedPattern"));
 	}
 
+	@Test
+	public void testBindDateTimeOverflow() {
+		MutablePropertyValues propertyValues = new MutablePropertyValues();
+		propertyValues.add("dateAnnotatedPattern", "02/29/09 12:00 PM");
+		binder.bind(propertyValues);
+		assertEquals(1, binder.getBindingResult().getErrorCount());
+	}
+
 	@Test
 	public void testBindISODate() {
 		MutablePropertyValues propertyValues = new MutablePropertyValues();

spring-context/src/test/java/org/springframework/format/datetime/joda/JodaTimeFormattingTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -317,6 +317,14 @@ public void testBindDateTimeAnnotatedPattern() {
 		assertEquals("10/31/09 12:00 PM", binder.getBindingResult().getFieldValue("dateTimeAnnotatedPattern"));
 	}
 
+	@Test
+	public void testBindDateTimeOverflow() {
+		MutablePropertyValues propertyValues = new MutablePropertyValues();
+		propertyValues.add("dateTimeAnnotatedPattern", "02/29/09 12:00 PM");
+		binder.bind(propertyValues);
+		assertEquals(1, binder.getBindingResult().getErrorCount());
+	}
+
 	@Test
 	public void testBindDateTimeAnnotatedDefault() {
 		MutablePropertyValues propertyValues = new MutablePropertyValues();

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -292,6 +292,14 @@ public void testBindDateTimeAnnotatedPattern() {
 		assertEquals("10/31/09 12:00 PM", binder.getBindingResult().getFieldValue("dateTimeAnnotatedPattern"));
 	}
 
+	@Test
+	public void testBindDateTimeOverflow() {
+		MutablePropertyValues propertyValues = new MutablePropertyValues();
+		propertyValues.add("dateTimeAnnotatedPattern", "02/29/09 12:00 PM");
+		binder.bind(propertyValues);
+		assertEquals(1, binder.getBindingResult().getErrorCount());
+	}
+
 	@Test
 	public void testBindISODate() {
 		MutablePropertyValues propertyValues = new MutablePropertyValues();