Consider getters using get as getter for boolean Kotlin properties.

We now additionally consider get-prefixed methods in addition to is-prefixed methods as getters for boolean properties.

Closes #3249

Author: mp911de

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

@@ -94,18 +94,9 @@ private static void collectKotlinProperties(Class<?> beanClass, Collection<KCall
 
 			if (member instanceof KProperty<?> property) {
 
-				Method getter = ReflectJvmMapping.getJavaGetter(property);
 				Method setter = property instanceof KMutableProperty<?> kmp ? ReflectJvmMapping.getJavaSetter(kmp) : null;
-
-				if (getter == null) {
-					Type javaType = ReflectJvmMapping.getJavaType(property.getReturnType());
-					getter = ReflectionUtils.findMethod(beanClass,
-							javaType == Boolean.TYPE ? "is" : "get" + StringUtils.capitalize(property.getName()));
-				}
-
-				if (getter != null) {
-					getter = ClassUtils.getMostSpecificMethod(getter, beanClass);
-				}
+				Type javaType = ReflectJvmMapping.getJavaType(property.getReturnType());
+				Method getter = findGetter(beanClass, property, javaType);
 
 				if (getter != null && (Modifier.isStatic(getter.getModifiers()) || getter.getParameterCount() != 0)) {
 					continue;
@@ -123,6 +114,21 @@ private static void collectKotlinProperties(Class<?> beanClass, Collection<KCall
 		}
 	}
 
+	private static @Nullable Method findGetter(Class<?> beanClass, KProperty<?> property, Type javaType) {
+
+		Method getter = ReflectJvmMapping.getJavaGetter(property);
+
+		if (getter == null && javaType == Boolean.TYPE) {
+			getter = ReflectionUtils.findMethod(beanClass, "is" + StringUtils.capitalize(property.getName()));
+		}
+
+		if (getter == null) {
+			getter = ReflectionUtils.findMethod(beanClass, "get" + StringUtils.capitalize(property.getName()));
+		}
+
+		return getter != null ? ClassUtils.getMostSpecificMethod(getter, beanClass) : null;
+	}
+
 	private static void collectBasicJavaProperties(Class<?> beanClass, Map<String, PropertyDescriptor> descriptors)
 			throws IntrospectionException {
 
@@ -204,5 +210,7 @@ public void setWriteMethod(@Nullable Method writeMethod) {
 		public Method getWriteMethod() {
 			return this.writeMethod;
 		}
+
 	}
+
 }

src/test/java/org/springframework/data/projection/ProxyProjectionFactoryUnitTests.java

@@ -342,6 +342,7 @@ void supportsNullableWrapperDateToLocalDateTimeConversion() {
 		assertThat(excerpt.getBirthdate()).contains(LocalDateTime.of(1967, 1, 9, 0, 0));
 	}
 
+
 	interface Contact {}
 
 	interface CustomerWithLocalDateTime {

src/test/kotlin/org/springframework/data/projection/Entities.kt

@@ -0,0 +1,40 @@
+/*
+ * 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.projection
+
+open class KClassWithJavaGetter() {
+
+	private var fromOuterSpace: Boolean = false
+
+	open fun getFromOuterSpace() = fromOuterSpace
+
+	open fun setFromOuterSpace(newValue: Boolean) {
+		this.fromOuterSpace = newValue
+	}
+
+}
+
+open class KClassWithIsGetter() {
+
+	private var fromOuterSpace: Boolean = false
+
+	open fun isFromOuterSpace() = fromOuterSpace
+
+	open fun setFromOuterSpace(newValue: Boolean) {
+		this.fromOuterSpace = newValue
+	}
+
+}

src/test/kotlin/org/springframework/data/util/KotlinBeanInfoFactoryUnitTests.kt

@@ -58,6 +58,16 @@ class KotlinBeanInfoFactoryUnitTests {
 		assertThat(pds).hasSize(1).extracting("name").contains("value")
 	}
 
+	@Test // GH-3249
+	internal fun considersBooleanGetAndIsGetters() {
+
+		val isAndGet = BeanUtils.getPropertyDescriptors(KClassWithIsGetter::class.java)
+		assertThat(isAndGet[0].readMethod.name).isEqualTo("isFromOuterSpace")
+
+		val getOnly = BeanUtils.getPropertyDescriptors(KClassWithGetGetter::class.java)
+		assertThat(getOnly[0].readMethod.name).isEqualTo("getFromOuterSpace")
+	}
+
 	@Test
 	internal fun determinesInlineClassConsumerProperties() {
 
@@ -200,4 +210,29 @@ class KotlinBeanInfoFactoryUnitTests {
 	class User : AbstractAuditable() {
 		var name: String? = null
 	}
+
+	open class KClassWithGetGetter() {
+
+		private var fromOuterSpace: Boolean = false
+
+		open fun getFromOuterSpace() = fromOuterSpace
+
+		open fun setFromOuterSpace(newValue: Boolean) {
+			this.fromOuterSpace = newValue
+		}
+	}
+
+	open class KClassWithIsGetter() {
+
+		private var fromOuterSpace: Boolean = false
+
+		open fun isFromOuterSpace() = fromOuterSpace
+
+		open fun getFromOuterSpace() = fromOuterSpace
+
+		open fun setFromOuterSpace(newValue: Boolean) {
+			this.fromOuterSpace = newValue
+		}
+	}
+
 }