Upgrade nullability plugin to 0.0.4

This commit also includes related refinements of
JdbcTemplate#getSingleColumnRowMapper and
ObjectUtils#addObjectToArray.

Closes gh-35340

build.gradle

@@ -6,7 +6,7 @@ plugins {
 	id 'com.github.bjornvester.xjc' version '1.8.2' apply false
 	id 'io.github.goooler.shadow' version '8.1.8' apply false
 	id 'me.champeau.jmh' version '0.7.2' apply false
-	id "io.spring.nullability" version "0.0.1" apply false
+	id 'io.spring.nullability' version '0.0.4' apply false
 }
 
 ext {

spring-core/src/main/java/org/springframework/util/ObjectUtils.java

@@ -255,7 +255,7 @@ public abstract class ObjectUtils {
 	 * @param obj the object to append
 	 * @return the new array (of the same component type; never {@code null})
 	 */
-	public static <A, O extends A> A[] addObjectToArray(A @Nullable [] array, @Nullable O obj) {
+	public static <A, O extends A> A[] addObjectToArray(A @Nullable [] array, O obj) {
 		return addObjectToArray(array, obj, (array != null ? array.length : 0));
 	}
 
@@ -268,17 +268,18 @@ public abstract class ObjectUtils {
 	 * @return the new array (of the same component type; never {@code null})
 	 * @since 6.0
 	 */
-	public static <A, O extends A> @Nullable A[] addObjectToArray(A @Nullable [] array, @Nullable O obj, int position) {
+	public static <A, O extends A> A[] addObjectToArray(A @Nullable [] array, O obj, int position) {
 		Class<?> componentType = Object.class;
 		if (array != null) {
 			componentType = array.getClass().componentType();
 		}
+		// Defensive code for use cases not following the declared nullability
 		else if (obj != null) {
 			componentType = obj.getClass();
 		}
 		int newArrayLength = (array != null ? array.length + 1 : 1);
 		@SuppressWarnings("unchecked")
-		@Nullable A[] newArray = (A[]) Array.newInstance(componentType, newArrayLength);
+		A[] newArray = (A[]) Array.newInstance(componentType, newArrayLength);
 		if (array != null) {
 			System.arraycopy(array, 0, newArray, 0, position);
 			System.arraycopy(array, position, newArray, position + 1, array.length - position);

spring-jdbc/src/main/java/org/springframework/jdbc/core/JdbcTemplate.java

@@ -1413,7 +1413,7 @@ public class JdbcTemplate extends JdbcAccessor implements JdbcOperations {
 	 * @return the RowMapper to use
 	 * @see SingleColumnRowMapper
 	 */
-	protected <T> RowMapper<@Nullable T> getSingleColumnRowMapper(Class<T> requiredType) {
+	protected <T extends @Nullable Object> RowMapper<T> getSingleColumnRowMapper(Class<T> requiredType) {
 		return new SingleColumnRowMapper<>(requiredType);
 	}