HHH-16385 Ensure QueryKey is immutable and serializable

hibernate-core/src/main/java/org/hibernate/cache/spi/QueryKey.java

@@ -8,6 +8,7 @@ package org.hibernate.cache.spi;
 
 import java.io.IOException;
 import java.io.Serializable;
+import java.util.Arrays;
 import java.util.Objects;
 import java.util.Set;
 
@@ -65,7 +66,7 @@ public class QueryKey implements Serializable {
 	private final Integer firstRow;
 	private final Integer maxRows;
 	private final String tenantIdentifier;
-	private final Set<String> enabledFilterNames;
+	private final String[] enabledFilterNames;
 
 	/**
 	 * For performance reasons, the hashCode is cached; however, it is marked transient so that it can be
@@ -85,7 +86,7 @@ public class QueryKey implements Serializable {
 		this.firstRow = firstRow;
 		this.maxRows = maxRows;
 		this.tenantIdentifier = tenantIdentifier;
-		this.enabledFilterNames = enabledFilterNames;
+		this.enabledFilterNames = enabledFilterNames.toArray( String[]::new );
 		this.hashCode = generateHashCode();
 	}
 
@@ -110,7 +111,7 @@ public class QueryKey implements Serializable {
 //		result = 37 * result + ( maxRows==null ? 0 : maxRows );
 		result = 37 * result + ( tenantIdentifier==null ? 0 : tenantIdentifier.hashCode() );
 		result = 37 * result + parameterBindingsMemento.hashCode();
-		result = 37 * result + ( enabledFilterNames == null ? 0 : enabledFilterNames.hashCode() );
+		result = 37 * result + Arrays.hashCode( enabledFilterNames );
 		return result;
 	}
 
@@ -146,7 +147,7 @@ public class QueryKey implements Serializable {
 			return false;
 		}
 
-		if ( ! Objects.equals( enabledFilterNames, that.enabledFilterNames ) ) {
+		if ( ! Arrays.equals( enabledFilterNames, that.enabledFilterNames ) ) {
 			return false;
 		}