Try type conversion for unique fallback write method as well

Closes gh-32329
See gh-32159

Author: jhoeller

Diff for: spring-beans/src/main/java/org/springframework/beans/BeanWrapperImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -21,6 +21,7 @@
 
 import org.apache.commons.logging.LogFactory;
 
+import org.springframework.core.MethodParameter;
 import org.springframework.core.ResolvableType;
 import org.springframework.core.convert.TypeDescriptor;
 import org.springframework.lang.Nullable;
@@ -283,16 +284,25 @@ public void setValue(@Nullable Object value) throws Exception {
 
 		@Override
 		public boolean setValueFallbackIfPossible(@Nullable Object value) {
-			Method writeMethod = this.pd.getWriteMethodFallback(value != null ? value.getClass() : null);
-			if (writeMethod != null) {
-				ReflectionUtils.makeAccessible(writeMethod);
-				try {
+			try {
+				Method writeMethod = this.pd.getWriteMethodFallback(value != null ? value.getClass() : null);
+				if (writeMethod == null) {
+					writeMethod = this.pd.getUniqueWriteMethodFallback();
+					if (writeMethod != null) {
+						// Conversion necessary as we would otherwise have received the method
+						// from the type-matching getWriteMethodFallback call above already
+						value = convertForProperty(this.pd.getName(), null, value,
+								new TypeDescriptor(new MethodParameter(writeMethod, 0)));
+					}
+				}
+				if (writeMethod != null) {
+					ReflectionUtils.makeAccessible(writeMethod);
 					writeMethod.invoke(getWrappedInstance(), value);
 					return true;
 				}
-				catch (Exception ex) {
-					LogFactory.getLog(BeanPropertyHandler.class).debug("Write method fallback failed", ex);
-				}
+			}
+			catch (Exception ex) {
+				LogFactory.getLog(BeanPropertyHandler.class).debug("Write method fallback failed", ex);
 			}
 			return false;
 		}

Diff for: spring-beans/src/main/java/org/springframework/beans/GenericTypeAwarePropertyDescriptor.java

@@ -171,6 +171,14 @@ public Method getWriteMethodFallback(@Nullable Class<?> valueType) {
 		return null;
 	}
 
+	@Nullable
+	public Method getUniqueWriteMethodFallback() {
+		if (this.ambiguousWriteMethods != null && this.ambiguousWriteMethods.size() == 1) {
+			return this.ambiguousWriteMethods.iterator().next();
+		}
+		return null;
+	}
+
 	public boolean hasUniqueWriteMethod() {
 		return (this.writeMethod != null && this.ambiguousWriteMethods == null);
 	}

Diff for: spring-beans/src/test/java/org/springframework/beans/factory/DefaultListableBeanFactoryTests.java

@@ -1342,6 +1342,11 @@ void withOverloadedSetters() {
 		rbd.getPropertyValues().add("value", Duration.ofSeconds(1000));
 		lbf.registerBeanDefinition("overloaded", rbd);
 		assertThat(lbf.getBean(SetterOverload.class).getObject()).isEqualTo("1000s");
+
+		rbd = new RootBeanDefinition(SetterOverload.class);
+		rbd.getPropertyValues().add("value", "1000");
+		lbf.registerBeanDefinition("overloaded", rbd);
+		assertThat(lbf.getBean(SetterOverload.class).getObject()).isEqualTo("1000i");
 	}
 
 	@Test
@@ -3369,13 +3374,13 @@ public String getObject() {
 			return this.value;
 		}
 
-		public void setValue(int length) {
-			this.value = length + "i";
-		}
-
 		public void setValue(Duration duration) {
 			this.value = duration.getSeconds() + "s";
 		}
+
+		public void setValue(int length) {
+			this.value = length + "i";
+		}
 	}