Introduce ObjectUtils#nullSafeHash(Object... element)

This commit deprecates the various nullSafeHashCode methods taking array
types as they are superseded by Arrays.hashCode now. This means that
the now only remaining nullSafeHashCode method does not trigger a
warning only if the target type is not an array. At the same time, there
are multiple use of this method on several elements, handling the
accumulation of hash codes.

For that reason, this commit also introduces a nullSafeHash that takes
an array of elements. The only difference between Objects.hash is that
this method handles arrays.

The codebase has been reviewed to use any of those two methods when it
is possible.

Closes gh-29051

spring-aop/src/main/java/org/springframework/aop/aspectj/AspectJExpressionPointcut.java

@@ -525,11 +525,8 @@ public class AspectJExpressionPointcut extends AbstractExpressionPointcut
 
 	@Override
 	public int hashCode() {
-		int hashCode = ObjectUtils.nullSafeHashCode(getExpression());
-		hashCode = 31 * hashCode + ObjectUtils.nullSafeHashCode(this.pointcutDeclarationScope);
-		hashCode = 31 * hashCode + ObjectUtils.nullSafeHashCode(this.pointcutParameterNames);
-		hashCode = 31 * hashCode + ObjectUtils.nullSafeHashCode(this.pointcutParameterTypes);
-		return hashCode;
+		return ObjectUtils.nullSafeHash(getExpression(), this.pointcutDeclarationScope,
+				this.pointcutParameterNames, this.pointcutParameterTypes);
 	}
 
 	@Override

spring-aop/src/main/java/org/springframework/aop/aspectj/TypePatternClassFilter.java

@@ -16,6 +16,8 @@
 
 package org.springframework.aop.aspectj;
 
+import java.util.Objects;
+
 import org.aspectj.weaver.tools.PointcutParser;
 import org.aspectj.weaver.tools.TypePatternMatcher;
 
@@ -124,7 +126,7 @@ public class TypePatternClassFilter implements ClassFilter {
 
 	@Override
 	public int hashCode() {
-		return ObjectUtils.nullSafeHashCode(this.typePattern);
+		return Objects.hashCode(this.typePattern);
 	}
 
 	@Override

spring-aop/src/main/java/org/springframework/aop/support/ClassFilters.java

@@ -129,7 +129,7 @@ public abstract class ClassFilters {
 
 		@Override
 		public int hashCode() {
-			return ObjectUtils.nullSafeHashCode(this.filters);
+			return Arrays.hashCode(this.filters);
 		}
 
 		@Override
@@ -170,7 +170,7 @@ public abstract class ClassFilters {
 
 		@Override
 		public int hashCode() {
-			return ObjectUtils.nullSafeHashCode(this.filters);
+			return Arrays.hashCode(this.filters);
 		}
 
 		@Override

spring-aop/src/main/java/org/springframework/aop/target/AbstractBeanFactoryBasedTargetSource.java

@@ -17,6 +17,7 @@
 package org.springframework.aop.target;
 
 import java.io.Serializable;
+import java.util.Objects;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -190,7 +191,7 @@ public abstract class AbstractBeanFactoryBasedTargetSource implements TargetSour
 
 	@Override
 	public int hashCode() {
-		return getClass().hashCode() * 13 + ObjectUtils.nullSafeHashCode(this.targetBeanName);
+		return Objects.hash(getClass(), this.targetBeanName);
 	}
 
 	@Override

spring-aop/src/main/java/org/springframework/aop/target/EmptyTargetSource.java

@@ -17,6 +17,7 @@
 package org.springframework.aop.target;
 
 import java.io.Serializable;
+import java.util.Objects;
 
 import org.springframework.aop.TargetSource;
 import org.springframework.lang.Nullable;
@@ -140,7 +141,7 @@ public final class EmptyTargetSource implements TargetSource, Serializable {
 
 	@Override
 	public int hashCode() {
-		return EmptyTargetSource.class.hashCode() * 13 + ObjectUtils.nullSafeHashCode(this.targetClass);
+		return Objects.hash(getClass(), this.targetClass);
 	}
 
 	@Override