Consider UUID as simple value type with concise toString output

Closes gh-30661

Author: jhoeller

spring-core/src/main/java/org/springframework/util/ObjectUtils.java

@@ -27,6 +27,7 @@
 import java.util.Map;
 import java.util.Optional;
 import java.util.StringJoiner;
+import java.util.UUID;
 
 import org.springframework.lang.Nullable;
 
@@ -903,14 +904,15 @@ public static String nullSafeToString(@Nullable short[] array) {
 	 * <li>Potentially {@linkplain StringUtils#truncate(CharSequence) truncated string}
 	 * if {@code obj} is a {@link String} or {@link CharSequence}</li>
 	 * <li>Potentially {@linkplain StringUtils#truncate(CharSequence) truncated string}
-	 * if {@code obj} is a <em>simple type</em> whose {@code toString()} method returns
-	 * a non-null value.</li>
+	 * if {@code obj} is a <em>simple value type</em> whose {@code toString()} method
+	 * returns a non-null value.</li>
 	 * <li>Otherwise, a string representation of the object's type name concatenated
 	 * with {@code @} and a hex string form of the object's identity hash code</li>
 	 * </ul>
-	 * <p>In the context of this method, a <em>simple type</em> is any of the following:
-	 * a primitive wrapper (excluding {@link Void}), an {@link Enum}, a {@link Number},
-	 * a {@link Date}, a {@link Temporal}, a {@link URI}, a {@link URL}, or a {@link Locale}.
+	 * <p>In the context of this method, a <em>simple value type</em> is any of the following:
+	 * a primitive wrapper (excluding {@code Void}), an {@code Enum}, a {@code Number},
+	 * a {@code Date}, a {@code Temporal}, a {@code UUID}, a {@code URI}, a {@code URL},
+	 * or a {@code Locale}.
 	 * @param obj the object to build a string representation for
 	 * @return a concise string representation of the supplied object
 	 * @since 5.3.27
@@ -938,13 +940,7 @@ public static String nullSafeConciseToString(@Nullable Object obj) {
 	}
 
 	/**
-	 * Copy of {@link org.springframework.beans.BeanUtils#isSimpleValueType(Class)}.
-	 * <p>Check if the given type represents a "simple" value type: a primitive or
-	 * primitive wrapper, an enum, a String or other CharSequence, a Number, a
-	 * Date, a Temporal, a URI, a URL, a Locale, or a Class.
-	 * <p>{@code Void} and {@code void} are not considered simple value types.
-	 * @param type the type to check
-	 * @return whether the given type represents a "simple" value type
+	 * Derived from {@link org.springframework.beans.BeanUtils#isSimpleValueType}.
 	 */
 	private static boolean isSimpleValueType(Class<?> type) {
 		return (Void.class != type && void.class != type &&
@@ -954,6 +950,7 @@ private static boolean isSimpleValueType(Class<?> type) {
 				Number.class.isAssignableFrom(type) ||
 				Date.class.isAssignableFrom(type) ||
 				Temporal.class.isAssignableFrom(type) ||
+				UUID.class.isAssignableFrom(type) ||
 				URI.class == type ||
 				URL.class == type ||
 				Locale.class == type ||

spring-core/src/test/java/org/springframework/util/ObjectUtilsTests.java

@@ -29,6 +29,7 @@
 import java.util.List;
 import java.util.Locale;
 import java.util.Set;
+import java.util.UUID;
 
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
@@ -800,6 +801,17 @@ void caseInsensitiveValueOf() {
 			.withMessage("Constant [bogus] does not exist in enum type org.springframework.util.ObjectUtilsTests$Tropes");
 	}
 
+
+	private static void assertEqualHashCodes(int expected, Object array) {
+		int actual = ObjectUtils.nullSafeHashCode(array);
+		assertThat(actual).isEqualTo(expected);
+		assertThat(array.hashCode()).isNotEqualTo(actual);
+	}
+
+
+	enum Tropes {FOO, BAR, baz}
+
+
 	@Nested
 	class NullSafeConciseToStringTests {
 
@@ -861,7 +873,13 @@ void nullSafeConciseToStringForTemporal() {
 		}
 
 		@Test
-		void nullSafeConciseToStringForUri() {
+		void nullSafeConciseToStringForUUID() {
+			UUID id = UUID.randomUUID();
+			assertThat(ObjectUtils.nullSafeConciseToString(id)).isEqualTo(id.toString());
+		}
+
+		@Test
+		void nullSafeConciseToStringForURI() {
 			String uri = "https://www.example.com/?foo=1&bar=2&baz=3";
 			assertThat(ObjectUtils.nullSafeConciseToString(URI.create(uri))).isEqualTo(uri);
 
@@ -873,7 +891,7 @@ void nullSafeConciseToStringForUri() {
 		}
 
 		@Test
-		void nullSafeConciseToStringForUrl() throws Exception {
+		void nullSafeConciseToStringForURL() throws Exception {
 			String url = "https://www.example.com/?foo=1&bar=2&baz=3";
 			assertThat(ObjectUtils.nullSafeConciseToString(new URL(url))).isEqualTo(url);
 
@@ -925,17 +943,6 @@ public String toString() {
 		private static String prefix(Class<?> clazz) {
 			return clazz.getTypeName() + "@";
 		}
-
-	}
-
-
-	private static void assertEqualHashCodes(int expected, Object array) {
-		int actual = ObjectUtils.nullSafeHashCode(array);
-		assertThat(actual).isEqualTo(expected);
-		assertThat(array.hashCode()).isNotEqualTo(actual);
 	}
 
-
-	enum Tropes {FOO, BAR, baz}
-
 }