Expose PropertyPathUtil.

Allow generic parsing of property paths from serialized lambdas.

Author: mp911de

src/main/java/org/springframework/data/core/PropertyUtil.java renamed to src/main/java/org/springframework/data/core/PropertyPathUtil.java

@@ -15,17 +15,62 @@
  */
 package org.springframework.data.core;
 
+import java.io.Serializable;
+import java.lang.invoke.SerializedLambda;
+import java.lang.reflect.Method;
 import java.util.Objects;
 
 import org.jspecify.annotations.Nullable;
 
+import org.springframework.dao.InvalidDataAccessApiUsageException;
+import org.springframework.util.Assert;
+import org.springframework.util.ReflectionUtils;
+
 /**
  * Utility class for {@link PropertyPath} and {@link PropertyReference} implementations.
  *
  * @author Mark Paluch
  * @since 4.1
  */
-class PropertyUtil {
+public class PropertyPathUtil {
+
+	/**
+	 * Resolve a {@link PropertyPath} from a {@link Serializable} lambda implementing a functional interface accepting a
+	 * single method argument and returning a value. The form of the interface must follow a design aligned with
+	 * {@link org.springframework.core.convert.converter.Converter} or {@link java.util.function.Function}.
+	 *
+	 * @param obj the serializable lambda object.
+	 * @return the resolved property path.
+	 */
+	public static PropertyPath resolve(Object obj) {
+
+		Assert.isInstanceOf(Serializable.class, obj, "Object must be Serializable");
+
+		return TypedPropertyPaths.of(new SerializableWrapper((Serializable) obj));
+	}
+
+	private record SerializableWrapper(Serializable serializable) implements PropertyReference<Object, Object> {
+
+		@Override
+		public @Nullable Object get(Object obj) {
+			return null;
+		}
+
+		// serializable bridge
+		public SerializedLambda writeReplace() {
+
+			Method method = ReflectionUtils.findMethod(serializable.getClass(), "writeReplace");
+
+			if (method == null) {
+				throw new InvalidDataAccessApiUsageException(
+						"Cannot find writeReplace method on " + serializable.getClass().getName());
+			}
+
+			ReflectionUtils.makeAccessible(method);
+			return (SerializedLambda) ReflectionUtils.invokeMethod(method, serializable);
+		}
+
+	}
 
 	/**
 	 * Compute the hash code for the given {@link PropertyPath} based on its {@link Object#toString() string}

src/test/java/org/springframework/data/core/PropertyPathUtilUnitTests.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright 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.core;
+
+import java.io.Serializable;
+
+import org.jspecify.annotations.Nullable;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.core.convert.converter.Converter;
+
+/**
+ * Unit test {@link PropertyPathUtil}.
+ *
+ * @author Mark Paluch
+ */
+class PropertyPathUtilUnitTests {
+
+	@Test
+	void shouldResolvePropertyPath() {
+
+		Converter<Person, String> c = convert(Person::getName);
+
+		System.out.println(PropertyPathUtil.resolve(c));
+	}
+
+	static <T, P, C extends Converter<T, P> & Serializable> Serializable of(C mapping) {
+		return mapping;
+	}
+
+	static <A, B, T extends Converter<A, B> & Serializable> T convert(T converter) {
+		return converter;
+	}
+
+	static class Person {
+
+		private String name;
+		private @Nullable Integer age;
+
+		// Getters
+		public String getName() {
+			return name;
+		}
+
+		public @Nullable Integer getAge() {
+			return age;
+		}
+
+	}
+}