Formal null safety for exception message through String.valueOf

See gh-33117

Author: jhoeller

spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractAutowireCapableBeanFactory.java

@@ -853,7 +853,8 @@ protected ResolvableType getTypeForFactoryBean(String beanName, RootBeanDefiniti
 			}
 		}
 		catch (IllegalArgumentException ex) {
-			throw new BeanDefinitionStoreException(mbd.getResourceDescription(), beanName, ex.getMessage());
+			throw new BeanDefinitionStoreException(mbd.getResourceDescription(), beanName,
+					String.valueOf(ex.getMessage()));
 		}
 
 		// For instance supplied beans, try the target type and bean class immediately

spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractBeanFactory.java

@@ -1723,7 +1723,8 @@ protected ResolvableType getTypeForFactoryBean(String beanName, RootBeanDefiniti
 			}
 		}
 		catch (IllegalArgumentException ex) {
-			throw new BeanDefinitionStoreException(mbd.getResourceDescription(), beanName, ex.getMessage());
+			throw new BeanDefinitionStoreException(mbd.getResourceDescription(), beanName,
+					String.valueOf(ex.getMessage()));
 		}
 
 		if (allowInit && mbd.isSingleton()) {