Use StableValue behind Lazy

ci/pipeline.properties

@@ -1,10 +1,10 @@
 # Java versions
-java.main.tag=24.0.1_9-jdk-noble
-java.next.tag=24.0.1_9-jdk-noble
+java.main.tag=25
+java.next.tag=25-cds
 
 # Docker container images - standard
-docker.java.main.image=library/eclipse-temurin:${java.main.tag}
-docker.java.next.image=library/eclipse-temurin:${java.next.tag}
+docker.java.main.image=bellsoft/liberica-openjdk-alpine:${java.main.tag}
+docker.java.next.image=bellsoft/liberica-openjdk-alpine:${java.next.tag}
 
 # Supported versions of MongoDB
 docker.mongodb.6.0.version=6.0.23

pom.xml

@@ -5,7 +5,7 @@
 
 	<groupId>org.springframework.data</groupId>
 	<artifactId>spring-data-commons</artifactId>
-	<version>4.0.0-SNAPSHOT</version>
+	<version>4.0.0-STABLE-VALUE-SNAPSHOT</version>
 
 	<name>Spring Data Core</name>
 	<description>Core Spring concepts underpinning every Spring Data module.</description>
@@ -341,18 +341,55 @@
 
 	<build>
 		<plugins>
+
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-assembly-plugin</artifactId>
 			</plugin>
+
 			<plugin>
 				<groupId>org.antora</groupId>
 				<artifactId>antora-maven-plugin</artifactId>
 			</plugin>
+
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-jar-plugin</artifactId>
+				<executions>
+					<execution>
+						<id>default-jar</id>
+						<configuration>
+							<archive>
+								<manifestEntries>
+									<Multi-Release>true</Multi-Release>
+								</manifestEntries>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-compiler-plugin</artifactId>
 				<executions>
+
+					<execution>
+						<id>jdk25</id>
+						<goals>
+							<goal>compile</goal>
+						</goals>
+						<configuration>
+							<enablePreview>true</enablePreview>
+							<release>25</release>
+							<compileSourceRoots>
+								<compileSourceRoot>${project.basedir}/src/main/java25
+								</compileSourceRoot>
+							</compileSourceRoots>
+							<multiReleaseOutput>true</multiReleaseOutput>
+						</configuration>
+					</execution>
+
 					<execution>
 						<id>java-test-compile</id>
 						<configuration>
@@ -366,8 +403,10 @@
 							</annotationProcessorPaths>
 						</configuration>
 					</execution>
+
 				</executions>
 			</plugin>
+
 		</plugins>
 	</build>
 

src/main/java/org/springframework/data/util/Lazy.java

@@ -22,7 +22,6 @@
 import org.jspecify.annotations.Nullable;
 
 import org.springframework.util.Assert;
-import org.springframework.util.ObjectUtils;
 
 /**
  * Simple value type to delay the creation of an object using a {@link Supplier} returning the produced object for
@@ -40,30 +39,14 @@
  */
 public class Lazy<T> implements Supplier<T> {
 
-	private static final Lazy<?> EMPTY = new Lazy<>(() -> null, null, true);
-	static final String UNRESOLVED = "[Unresolved]";
+	private static final Lazy<?> EMPTY = new Lazy<>(() -> null);
 
-	private final Supplier<? extends @Nullable T> supplier;
+	static final String UNRESOLVED = "[Unresolved]";
 
-	private @Nullable T value;
-	private volatile boolean resolved;
+	private final LazyDelegate<? extends @Nullable T> adapter;
 
-	private Lazy(Supplier<? extends @Nullable T> supplier) {
-		this(supplier, null, false);
-	}
-
-	/**
-	 * Creates a new {@code Lazy} for the given {@link Supplier}, value and whether it has been resolved or not.
-	 *
-	 * @param supplier must not be {@literal null}.
-	 * @param value can be {@literal null}.
-	 * @param resolved whether the value handed into the constructor represents a resolved value.
-	 */
-	private Lazy(Supplier<? extends @Nullable T> supplier, @Nullable T value, boolean resolved) {
-
-		this.supplier = supplier;
-		this.value = value;
-		this.resolved = resolved;
+	private Lazy(Supplier<? extends @Nullable T> adapter) {
+		this.adapter = new LazyDelegate<>(adapter);
 	}
 
 	/**
@@ -128,16 +111,7 @@ public T get() {
 	 */
 	@Nullable
 	public T getNullable() {
-
-		if (resolved) {
-			return value;
-		}
-
-		T result = supplier.get();
-		this.value = result;
-		this.resolved = true;
-
-		return result;
+		return adapter.getNullable();
 	}
 
 	/**
@@ -249,35 +223,22 @@ public boolean equals(@Nullable Object o) {
 			return false;
 		}
 
-		if (resolved != lazy.resolved) {
-			return false;
-		}
-
-		if (!ObjectUtils.nullSafeEquals(supplier, lazy.supplier)) {
-			return false;
-		}
-
-		return ObjectUtils.nullSafeEquals(value, lazy.value);
+		return adapter.equals(lazy.adapter);
 	}
 
 	@Override
 	public int hashCode() {
-
-		int result = ObjectUtils.nullSafeHashCode(supplier);
-
-		result = 31 * result + ObjectUtils.nullSafeHashCode(value);
-		result = 31 * result + (resolved ? 1 : 0);
-
-		return result;
+		return adapter.hashCode();
 	}
 
 	@Override
 	public String toString() {
 
-		if (!resolved) {
+		if (!adapter.isResolved()) {
 			return UNRESOLVED;
 		}
 
+		T value = getNullable();
 		return value == null ? "null" : value.toString();
 	}
 
@@ -293,6 +254,6 @@ public String toString(Supplier<String> fallback) {
 
 		Assert.notNull(fallback, "Fallback must not be null!");
 
-		return resolved ? toString() : fallback.get();
+		return adapter.isResolved() ? toString() : fallback.get();
 	}
 }

src/main/java/org/springframework/data/util/LazyDelegate.java

@@ -0,0 +1,102 @@
+/*
+ * Copyright 2016-2025 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
+ *
+ *      https://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.data.util;
+
+import java.util.function.Supplier;
+
+import org.jspecify.annotations.Nullable;
+
+import org.springframework.util.ObjectUtils;
+
+/**
+ * Simple lazy implementation using lazy value resolution. Lazy evaluation not guarded with locks and can therefore lead
+ * to multiple invocations of the underlying {@link Supplier}.
+ *
+ * @author Oliver Gierke
+ * @author Mark Paluch
+ * @author Henning Rohlfs
+ * @author Johannes Englmeier
+ * @author Greg Turnquist
+ * @since 4.0
+ */
+class LazyDelegate<T extends @Nullable Object> {
+
+	private final Supplier<T> supplier;
+
+	private @Nullable T value;
+	private volatile boolean resolved;
+
+	LazyDelegate(Supplier<T> supplier) {
+		this.supplier = supplier;
+	}
+
+	/**
+	 * Returns the value of the lazy evaluation.
+	 *
+	 * @return the value of the lazy evaluation, can be {@literal null}.
+	 */
+	@Nullable
+	public T getNullable() {
+
+		if (resolved) {
+			return value;
+		}
+
+		T result = supplier.get();
+		this.value = result;
+		this.resolved = true;
+
+		return result;
+	}
+
+	public boolean isResolved() {
+		return resolved;
+	}
+
+	@Override
+	public boolean equals(@Nullable Object o) {
+
+		if (this == o) {
+			return true;
+		}
+
+		if (!(o instanceof LazyDelegate<?> lazy)) {
+			return false;
+		}
+
+		if (resolved != lazy.resolved) {
+			return false;
+		}
+
+		if (!ObjectUtils.nullSafeEquals(supplier, lazy.supplier)) {
+			return false;
+		}
+
+		return ObjectUtils.nullSafeEquals(value, lazy.value);
+	}
+
+	@Override
+	public int hashCode() {
+
+		int result = ObjectUtils.nullSafeHashCode(supplier);
+
+		result = 31 * result + ObjectUtils.nullSafeHashCode(value);
+		result = 31 * result + (resolved ? 1 : 0);
+
+		return result;
+	}
+
+}

src/main/java25/org/springframework/data/util/LazyDelegate.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2016-2025 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
+ *
+ *      https://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.data.util;
+
+import java.util.function.Supplier;
+
+import org.jspecify.annotations.Nullable;
+
+import org.springframework.util.ObjectUtils;
+
+/**
+ * Lazy adapter using {@link StableValue}.
+ *
+ * @author Mark Paluch
+ * @since 4.0
+ */
+class LazyDelegate<T extends @Nullable Object> {
+
+	private final Supplier<T> supplier;
+	private final StableValue<T> value;
+
+	LazyDelegate(Supplier<T> supplier) {
+
+		System.out.println("Stable");
+		this.supplier = supplier;
+		this.value = StableValue.of();
+	}
+
+	/**
+	 * Returns the value of the lazy evaluation.
+	 *
+	 * @return the value of the lazy evaluation, can be {@literal null}.
+	 */
+	@Nullable
+	public T getNullable() {
+		return value.orElseSet(supplier);
+	}
+
+	public boolean isResolved() {
+		return value.isSet();
+	}
+
+	@Override
+	public boolean equals(@Nullable Object o) {
+
+		if (this == o) {
+			return true;
+		}
+
+		if (!(o instanceof LazyDelegate<?> lazy)) {
+			return false;
+		}
+
+		return ObjectUtils.nullSafeEquals(value, lazy.value);
+	}
+
+	@Override
+	public int hashCode() {
+		return value.hashCode();
+	}
+
+}