get rid of TruthValue and use Boolean

clean it up a bit

hibernate-core/src/main/java/org/hibernate/boot/model/TruthValue.java

@@ -1,40 +0,0 @@
-/*
- * SPDX-License-Identifier: LGPL-2.1-or-later
- * Copyright Red Hat Inc. and Hibernate Authors
- */
-package org.hibernate.boot.model;
-
-/**
- * An enumeration of truth values.
- *
- * @implNote Sure, this could be handled with {@code Boolean}, but
- *           that option is vulnerable to unwanted auto-unboxing
- *           and {@link NullPointerException}s.
- *
- * @author Steve Ebersole
- */
-public enum TruthValue {
-	TRUE,
-	FALSE,
-	UNKNOWN;
-
-	public static TruthValue of(boolean bool) {
-		return bool ? TRUE : FALSE;
-	}
-
-	public boolean toBoolean(boolean defaultValue) {
-		return switch ( this ) {
-			case TRUE -> true;
-			case FALSE -> false;
-			default -> defaultValue;
-		};
-	}
-
-	/**
-	 * @deprecated No longer used
-	 */
-	@Deprecated(since = "7", forRemoval = true)
-	public static boolean toBoolean(TruthValue value, boolean defaultValue) {
-		return value != null ? value.toBoolean( defaultValue ) : defaultValue;
-	}
-}

hibernate-core/src/main/java/org/hibernate/boot/model/source/internal/hbm/AbstractEntitySourceImpl.java

@@ -22,7 +22,6 @@ import org.hibernate.boot.jaxb.hbm.spi.JaxbHbmRootEntityType;
 import org.hibernate.boot.jaxb.hbm.spi.JaxbHbmSecondaryTableType;
 import org.hibernate.boot.jaxb.hbm.spi.SecondaryTableContainer;
 import org.hibernate.boot.model.CustomSql;
-import org.hibernate.boot.model.TruthValue;
 import org.hibernate.boot.model.source.spi.AttributePath;
 import org.hibernate.boot.model.source.spi.AttributeRole;
 import org.hibernate.boot.model.source.spi.AttributeSource;
@@ -391,10 +390,4 @@ public abstract class AbstractEntitySourceImpl
 		return jaxbEntityMapping.getSqlQuery();
 	}
 
-	@Override
-	public TruthValue quoteIdentifiersLocalToEntity() {
-		// HBM does not allow for this
-		return TruthValue.UNKNOWN;
-	}
-
 }

hibernate-core/src/main/java/org/hibernate/boot/model/source/internal/hbm/ColumnAttributeSourceImpl.java

@@ -6,7 +6,6 @@ package org.hibernate.boot.model.source.internal.hbm;
 
 import java.util.Set;
 
-import org.hibernate.boot.model.TruthValue;
 import org.hibernate.boot.model.source.spi.ColumnSource;
 import org.hibernate.boot.model.source.spi.JdbcDataType;
 import org.hibernate.boot.model.source.spi.SizeSource;
@@ -24,8 +23,8 @@ class ColumnAttributeSourceImpl
 	private final String tableName;
 	private final String columnName;
 	private final SizeSource sizeSource;
-	private final TruthValue nullable;
+	private final Boolean nullable;
-	private final TruthValue unique;
+	private final Boolean unique;
 	private final Set<String> indexConstraintNames;
 	private final Set<String> ukConstraintNames;
 
@@ -34,8 +33,8 @@ class ColumnAttributeSourceImpl
 			String tableName,
 			String columnName,
 			SizeSource sizeSource,
-			TruthValue nullable,
+			Boolean nullable,
-			TruthValue unique,
+			Boolean unique,
 			Set<String> indexConstraintNames,
 			Set<String> ukConstraintNames) {
 		super( mappingDocument );
@@ -64,7 +63,7 @@ class ColumnAttributeSourceImpl
 	}
 
 	@Override
-	public TruthValue isNullable() {
+	public Boolean isNullable() {
 		return nullable;
 	}
 
@@ -100,7 +99,7 @@ class ColumnAttributeSourceImpl
 
 	@Override
 	public boolean isUnique() {
-		return unique == TruthValue.TRUE;
+		return unique == Boolean.TRUE;
 	}
 
 	@Override

hibernate-core/src/main/java/org/hibernate/boot/model/source/internal/hbm/ColumnSourceImpl.java

@@ -5,16 +5,15 @@
 package org.hibernate.boot.model.source.internal.hbm;
 
 
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
 
 import org.hibernate.boot.jaxb.hbm.spi.JaxbHbmColumnType;
-import org.hibernate.boot.model.TruthValue;
 import org.hibernate.boot.model.source.spi.ColumnSource;
 import org.hibernate.boot.model.source.spi.JdbcDataType;
 import org.hibernate.boot.model.source.spi.SizeSource;
 
+import static java.util.Collections.addAll;
 import static org.hibernate.internal.util.StringHelper.splitAtCommas;
 
 /**
@@ -25,7 +24,7 @@ class ColumnSourceImpl
 		implements ColumnSource {
 	private final String tableName;
 	private final JaxbHbmColumnType columnElement;
-	private final TruthValue nullable;
+	private final Boolean nullable;
 	private final Set<String> indexConstraintNames;
 	private final Set<String> ukConstraintNames;
 
@@ -39,27 +38,19 @@ class ColumnSourceImpl
 				mappingDocument,
 				tableName,
 				columnElement,
-				interpretNotNullToNullability( columnElement.isNotNull() ),
+				columnElement.isNotNull() == null
+						? null
+						: !columnElement.isNotNull(),
 				indexConstraintNames,
 				ukConstraintNames
 		);
 	}
 
-	private static TruthValue interpretNotNullToNullability(Boolean notNull) {
-		if ( notNull == null ) {
-			return TruthValue.UNKNOWN;
-		}
-		else {
-			// not-null == nullable, so the booleans are reversed
-			return notNull ? TruthValue.FALSE : TruthValue.TRUE;
-		}
-	}
-
 	ColumnSourceImpl(
 			MappingDocument mappingDocument,
 			String tableName,
 			JaxbHbmColumnType columnElement,
-			TruthValue nullable,
+			Boolean nullable,
 			Set<String> indexConstraintNames,
 			Set<String> ukConstraintNames) {
 		super( mappingDocument );
@@ -86,7 +77,7 @@ class ColumnSourceImpl
 	}
 
 	@Override
-	public TruthValue isNullable() {
+	public Boolean isNullable() {
 		return nullable;
 	}
 
@@ -126,8 +117,8 @@ class ColumnSourceImpl
 
 	@Override
 	public boolean isUnique() {
-		// TODO: should TruthValue be returned instead of boolean?
+		return columnElement.isUnique() != null
-		return columnElement.isUnique() != null && columnElement.isUnique().booleanValue();
+			&& columnElement.isUnique();
 	}
 
 	@Override
@@ -160,8 +151,8 @@ class ColumnSourceImpl
 			return stringSet;
 		}
 		else {
-			HashSet<String> set = new HashSet<>( stringSet );
+			final HashSet<String> set = new HashSet<>( stringSet );
-			Collections.addAll( set, splitAtCommas( values ) );
+			addAll( set, splitAtCommas( values ) );
 			return set;
 		}
 	}

hibernate-core/src/main/java/org/hibernate/boot/model/source/internal/hbm/RelationalObjectBinder.java

@@ -7,7 +7,6 @@ package org.hibernate.boot.model.source.internal.hbm;
 import java.util.Collections;
 import java.util.List;
 
-import org.hibernate.boot.model.TruthValue;
 import org.hibernate.boot.model.naming.Identifier;
 import org.hibernate.boot.model.naming.PhysicalNamingStrategy;
 import org.hibernate.boot.model.relational.Database;
@@ -150,7 +149,8 @@ public class RelationalObjectBinder {
 			}
 		}
 
-		column.setNullable( interpretNullability( columnSource.isNullable(), areColumnsNullableByDefault ) );
+		final Boolean nullable = columnSource.isNullable();
+		column.setNullable( nullable == null ? areColumnsNullableByDefault : nullable );
 
 		column.setUnique( columnSource.isUnique() );
 		if ( columnSource.isUnique() && table != null ) {
@@ -182,15 +182,6 @@ public class RelationalObjectBinder {
 		}
 	}
 
-	private static boolean interpretNullability(TruthValue nullable, boolean areColumnsNullableByDefault) {
-		if ( nullable == null || nullable == TruthValue.UNKNOWN ) {
-			return areColumnsNullableByDefault;
-		}
-		else {
-			return nullable == TruthValue.TRUE;
-		}
-	}
-
 	public void bindFormulas(
 			MappingDocument sourceDocument,
 			List<DerivedValueSource> formulaSources,

hibernate-core/src/main/java/org/hibernate/boot/model/source/internal/hbm/RelationalValueSourceHelper.java

@@ -12,14 +12,14 @@ import java.util.Set;
 
 import org.hibernate.boot.MappingException;
 import org.hibernate.boot.jaxb.hbm.spi.JaxbHbmColumnType;
-import org.hibernate.boot.model.TruthValue;
 import org.hibernate.boot.model.source.spi.ColumnSource;
 import org.hibernate.boot.model.source.spi.DerivedValueSource;
 import org.hibernate.boot.model.source.spi.RelationalValueSource;
 import org.hibernate.boot.model.source.spi.SizeSource;
-import org.hibernate.internal.util.StringHelper;
 import org.hibernate.internal.util.collections.CollectionHelper;
 
+import static org.hibernate.internal.util.StringHelper.isNotEmpty;
+
 /**
  * @author Steve Ebersole
  */
@@ -152,7 +152,7 @@ public class RelationalValueSourceHelper {
 		if ( sources.size() > 1 ) {
 			final String errorMessage;
 			if ( columnsAndFormulasSource.getSourceType().canBeNamed()
-					&& StringHelper.isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
+					&& isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
 				errorMessage = String.format(
 						Locale.ENGLISH,
 						"Expecting just a single formula/column in context of <%s name=\"%s\"/>",
@@ -197,7 +197,7 @@ public class RelationalValueSourceHelper {
 		if ( sources.size() > 1 ) {
 			final String errorMessage;
 			if ( columnsAndFormulasSource.getSourceType().canBeNamed()
-					&& StringHelper.isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
+					&& isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
 				errorMessage = String.format(
 						Locale.ENGLISH,
 						"Expecting just a single formula/column in context of <%s name=\"%s\"/>",
@@ -219,7 +219,7 @@ public class RelationalValueSourceHelper {
 		if ( !(result instanceof ColumnSource) ) {
 			final String errorMessage;
 			if ( columnsAndFormulasSource.getSourceType().canBeNamed()
-					&& StringHelper.isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
+					&& isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
 				errorMessage = String.format(
 						Locale.ENGLISH,
 						"Expecting single column in context of <%s name=\"%s\"/>, but found formula [%s]",
@@ -267,7 +267,7 @@ public class RelationalValueSourceHelper {
 			if ( !(source instanceof ColumnSource) ) {
 				final String errorMessage;
 				if ( columnsAndFormulasSource.getSourceType().canBeNamed()
-						&& StringHelper.isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
+						&& isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
 					errorMessage = String.format(
 							Locale.ENGLISH,
 							"Expecting only columns in context of <%s name=\"%s\"/>, but found formula [%s]",
@@ -307,7 +307,7 @@ public class RelationalValueSourceHelper {
 			ColumnsAndFormulasSource columnsAndFormulasSource) {
 		List<RelationalValueSource> result = new ArrayList<>();
 
-		if ( StringHelper.isNotEmpty( columnsAndFormulasSource.getFormulaAttribute() ) ) {
+		if ( isNotEmpty( columnsAndFormulasSource.getFormulaAttribute() ) ) {
 			// we have an explicit formula attribute (i.e., <SOMETHING formula="abc"/>)
 			validateUseOfFormulaAttribute( mappingDocument, columnsAndFormulasSource );
 
@@ -359,8 +359,8 @@ public class RelationalValueSourceHelper {
 							containingTableName,
 							columnsAndFormulasSource.getColumnAttribute(),
 							columnsAndFormulasSource.getSizeSource(),
-							interpretNullabilityToTruthValue( columnsAndFormulasSource.isNullable() ),
+							columnsAndFormulasSource.isNullable(),
-							columnsAndFormulasSource.isUnique() ? TruthValue.TRUE : TruthValue.FALSE,
+							columnsAndFormulasSource.isUnique(),
 							columnsAndFormulasSource.getIndexConstraintNames(),
 							columnsAndFormulasSource.getUniqueKeyConstraintNames()
 					)
@@ -370,23 +370,14 @@ public class RelationalValueSourceHelper {
 		return result;
 	}
 
-	private static TruthValue interpretNullabilityToTruthValue(Boolean nullable) {
-		if ( nullable == null ) {
-			return TruthValue.UNKNOWN;
-		}
-		else {
-			return nullable ? TruthValue.TRUE : TruthValue.FALSE;
-		}
-	}
-
 	private static void validateUseOfFormulaAttribute(
 			MappingDocument sourceDocument,
 			ColumnsAndFormulasSource columnsAndFormulasSource) {
 		//		1) make sure there is no column attribute
-		if ( StringHelper.isNotEmpty( columnsAndFormulasSource.getColumnAttribute() ) ) {
+		if ( isNotEmpty( columnsAndFormulasSource.getColumnAttribute() ) ) {
 			final String errorMessage;
 			if ( columnsAndFormulasSource.getSourceType().canBeNamed()
-					&& StringHelper.isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
+					&& isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
 				errorMessage = String.format(
 						Locale.ENGLISH,
 						"column attribute and formula attribute may not be specified together near <%s name=\"%s\" column=\"%s\" formula=\"%s\" />",
@@ -411,7 +402,7 @@ public class RelationalValueSourceHelper {
 		if ( CollectionHelper.isNotEmpty( columnsAndFormulasSource.getColumnOrFormulaElements() ) ) {
 			final String errorMessage;
 			if ( columnsAndFormulasSource.getSourceType().canBeNamed()
-					&& StringHelper.isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
+					&& isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
 				errorMessage = String.format(
 						Locale.ENGLISH,
 						"formula attribute may not be specified along with <column/> or <formula/> subelement(s) near <%s name=\"%s\" formula=\"%s\" />",
@@ -435,10 +426,10 @@ public class RelationalValueSourceHelper {
 	private static void validateUseOfColumnOrFormulaNestedElements(
 			MappingDocument sourceDocument,
 			ColumnsAndFormulasSource columnsAndFormulasSource) {
-		if ( StringHelper.isNotEmpty( columnsAndFormulasSource.getColumnAttribute() ) ) {
+		if ( isNotEmpty( columnsAndFormulasSource.getColumnAttribute() ) ) {
 			final String errorMessage;
 			if ( columnsAndFormulasSource.getSourceType().canBeNamed()
-					&& StringHelper.isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
+					&& isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
 				errorMessage = String.format(
 						Locale.ENGLISH,
 						"column attribute may not be specified along with <column/> or <formula/> subelement(s) near <%s name=\"%s\" column=\"%s\" />",
@@ -467,7 +458,7 @@ public class RelationalValueSourceHelper {
 		if ( customWrite != null && !customWrite.matches("[^?]*\\?[^?]*") ) {
 			final String errorMessage;
 			if ( columnsAndFormulasSource.getSourceType().canBeNamed()
-					&& StringHelper.isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
+					&& isNotEmpty( columnsAndFormulasSource.getSourceName() ) ) {
 				errorMessage = String.format(
 						Locale.ENGLISH,
 						"write expression must contain exactly one value placeholder ('?') character near <column name=\"%s\" ... write=\"%s\" /> for <%s name=\"%s\" />",

hibernate-core/src/main/java/org/hibernate/boot/model/source/spi/Caching.java

@@ -5,7 +5,6 @@
 package org.hibernate.boot.model.source.spi;
 
 import org.hibernate.boot.CacheRegionDefinition;
-import org.hibernate.boot.model.TruthValue;
 import org.hibernate.cache.spi.access.AccessType;
 
 import static org.hibernate.internal.util.StringHelper.isEmpty;
@@ -17,25 +16,21 @@ import static org.hibernate.internal.util.StringHelper.isEmpty;
  * @author Hardy Ferentschik
  */
 public class Caching {
-	// NOTE : TruthValue for now because I need to look at how JPA's SharedCacheMode concept is handled
+	private Boolean requested;
-	private TruthValue requested;
 	private String region;
 	private AccessType accessType;
 	private boolean cacheLazyProperties;
 
-	public Caching() {
+	public Caching() {}
-		this.requested = TruthValue.UNKNOWN;
-	}
 
 	public Caching(String region, AccessType accessType, boolean cacheLazyProperties) {
-		this.requested = TruthValue.UNKNOWN;
 		this.region = region;
 		this.accessType = accessType;
 		this.cacheLazyProperties = cacheLazyProperties;
 	}
 
 	public Caching(String region, AccessType accessType, boolean cacheLazyProperties, boolean requested) {
-		this.requested = TruthValue.of( requested );
+		this.requested = requested;
 		this.region = region;
 		this.accessType = accessType;
 		this.cacheLazyProperties = cacheLazyProperties;
@@ -66,20 +61,20 @@ public class Caching {
 	}
 
 	public boolean isRequested() {
-		return requested == TruthValue.TRUE;
+		return requested == Boolean.TRUE;
 	}
 
 	public boolean isRequested(boolean defaultValue) {
-		return requested == TruthValue.UNKNOWN ? defaultValue : isRequested();
+		return requested == null ? defaultValue : isRequested();
 	}
 
 	public void setRequested(boolean requested) {
-		this.requested = TruthValue.of(requested);
+		this.requested = requested;
 	}
 
 	public void overlay(CacheRegionDefinition overrides) {
 		if ( overrides != null ) {
-			requested = TruthValue.TRUE;
+			requested = true;
 			accessType = AccessType.fromExternalName( overrides.getUsage() );
 			if ( isEmpty( overrides.getRegion() ) ) {
 				region = overrides.getRegion();
@@ -105,5 +100,4 @@ public class Caching {
 				+ ", cacheLazyProperties=" + cacheLazyProperties
 				+ ", requested=" + requested + '}';
 	}
-
 }

hibernate-core/src/main/java/org/hibernate/boot/model/source/spi/ColumnSource.java

@@ -6,8 +6,6 @@ package org.hibernate.boot.model.source.spi;
 
 import java.util.Set;
 
-import org.hibernate.boot.model.TruthValue;
-
 /**
  * Contract for source information pertaining to a physical column definition specific to a particular attribute
  * context.
@@ -44,7 +42,7 @@ public interface ColumnSource extends RelationalValueSource {
 	 *
 	 * @return {@code true} indicates it is nullable; {@code false} non-nullable.
 	 */
-	TruthValue isNullable();
+	Boolean isNullable();
 
 	/**
 	 * Obtain a specified default value for the column

hibernate-core/src/main/java/org/hibernate/boot/model/source/spi/EntitySource.java

@@ -10,7 +10,6 @@ import java.util.Map;
 import org.hibernate.boot.jaxb.hbm.spi.JaxbHbmNamedNativeQueryType;
 import org.hibernate.boot.jaxb.hbm.spi.JaxbHbmNamedQueryType;
 import org.hibernate.boot.model.CustomSql;
-import org.hibernate.boot.model.TruthValue;
 
 /**
  * Contract describing source of information related to mapping an entity.
@@ -146,7 +145,4 @@ public interface EntitySource extends IdentifiableTypeSource, ToolingHintContext
 	List<JaxbHbmNamedQueryType> getNamedQueries();
 
 	List<JaxbHbmNamedNativeQueryType> getNamedNativeQueries();
-
-	TruthValue quoteIdentifiersLocalToEntity();
-
 }

hibernate-core/src/main/java/org/hibernate/mapping/Column.java

@@ -14,7 +14,6 @@ import org.hibernate.AssertionFailure;
 import org.hibernate.Internal;
 import org.hibernate.MappingException;
 import org.hibernate.boot.Metadata;
-import org.hibernate.boot.model.TruthValue;
 import org.hibernate.boot.model.naming.Identifier;
 import org.hibernate.boot.model.relational.Database;
 import org.hibernate.boot.spi.MetadataBuildingContext;
@@ -435,8 +434,8 @@ public class Column implements Selectable, Serializable, Cloneable, ColumnTypeIn
 	}
 
 	@Override
-	public TruthValue getNullable() {
+	public Boolean getNullable() {
-		return nullable ? TruthValue.TRUE : TruthValue.FALSE;
+		return nullable;
 	}
 
 	@Override

hibernate-core/src/main/java/org/hibernate/tool/schema/extract/internal/AbstractInformationExtractorImpl.java

@@ -18,7 +18,6 @@ import java.util.Objects;
 import java.util.StringTokenizer;
 
 import org.hibernate.JDBCException;
-import org.hibernate.boot.model.TruthValue;
 import org.hibernate.boot.model.naming.DatabaseIdentifier;
 import org.hibernate.boot.model.naming.Identifier;
 import org.hibernate.boot.model.relational.QualifiedTableName;
@@ -50,7 +49,7 @@ public abstract class AbstractInformationExtractorImpl implements InformationExt
 
 	private final String[] tableTypes;
 
-	private String[] extraPhysicalTableTypes;
+	private final String[] extraPhysicalTableTypes;
 
 	private final ExtractionContext extractionContext;
 
@@ -430,8 +429,8 @@ public abstract class AbstractInformationExtractorImpl implements InformationExt
 						.getIdentifierHelper()
 						.toIdentifier( extractionContext.getJdbcConnection().getSchema() );
 			}
-			catch (SQLException ignore) {
+			catch (SQLException sqle) {
-				LOG.sqlWarning( ignore.getErrorCode(), ignore.getSQLState() );
+				LOG.sqlWarning( sqle.getErrorCode(), sqle.getSQLState() );
 			}
 			catch (AbstractMethodError ignore) {
 				// jConnect and jTDS report that they "support" schemas, but they don't really
@@ -911,25 +910,24 @@ public abstract class AbstractInformationExtractorImpl implements InformationExt
 		}
 	}
 
-	protected TruthValue interpretNullable(int nullable) {
+	protected Boolean interpretNullable(int nullable) {
-		switch ( nullable ) {
+		return switch ( nullable ) {
-			case ResultSetMetaData.columnNullable:
+			case ResultSetMetaData.columnNullable -> Boolean.TRUE;
-				return TruthValue.TRUE;
+			case ResultSetMetaData.columnNoNulls -> Boolean.FALSE;
-			case ResultSetMetaData.columnNoNulls:
+			default -> null;
-				return TruthValue.FALSE;
+		};
-			default:
-				return TruthValue.UNKNOWN;
-		}
 	}
 
-	private TruthValue interpretTruthValue(String nullable) {
+	private Boolean interpretTruthValue(String nullable) {
 		if ( "yes".equalsIgnoreCase( nullable ) ) {
-			return TruthValue.TRUE;
+			return Boolean.TRUE;
 		}
 		else if ( "no".equalsIgnoreCase( nullable ) ) {
-			return TruthValue.FALSE;
+			return Boolean.FALSE;
+		}
+		else {
+			return null;
 		}
-		return TruthValue.UNKNOWN;
 	}
 
 	// This method is not currently used.

hibernate-core/src/main/java/org/hibernate/tool/schema/extract/internal/ColumnInformationImpl.java

@@ -4,7 +4,6 @@
  */
 package org.hibernate.tool.schema.extract.internal;
 
-import org.hibernate.boot.model.TruthValue;
 import org.hibernate.boot.model.naming.Identifier;
 import org.hibernate.tool.schema.extract.spi.ColumnInformation;
 import org.hibernate.tool.schema.extract.spi.TableInformation;
@@ -23,7 +22,7 @@ public class ColumnInformationImpl implements ColumnInformation {
 	private final String typeName;
 	private final int columnSize;
 	private final int decimalDigits;
-	private final TruthValue nullable;
+	private final Boolean nullable;
 
 	public ColumnInformationImpl(
 			TableInformation containingTableInformation,
@@ -32,7 +31,7 @@ public class ColumnInformationImpl implements ColumnInformation {
 			String typeName,
 			int columnSize,
 			int decimalDigits,
-			TruthValue nullable) {
+			Boolean nullable) {
 		this.containingTableInformation = containingTableInformation;
 		this.columnIdentifier = columnIdentifier;
 		this.typeCode = typeCode;
@@ -73,7 +72,7 @@ public class ColumnInformationImpl implements ColumnInformation {
 	}
 
 	@Override
-	public TruthValue getNullable() {
+	public Boolean getNullable() {
 		return nullable;
 	}
 

hibernate-core/src/main/java/org/hibernate/tool/schema/extract/spi/ColumnInformation.java

@@ -4,7 +4,6 @@
  */
 package org.hibernate.tool.schema.extract.spi;
 
-import org.hibernate.boot.model.TruthValue;
 import org.hibernate.boot.model.naming.Identifier;
 
 /**
@@ -29,11 +28,13 @@ public interface ColumnInformation extends ColumnTypeInformation {
 	Identifier getColumnIdentifier();
 
 	/**
-	 * Is the column nullable.  The database is allowed to report unknown, hence the use of TruthValue
+	 * Is the column nullable.
+	 * <p>
+	 * The database is allowed to report unknown, hence the use of {@link Boolean}.
 	 *
-	 * @return nullability.
+	 * @return nullability, if known
 	 */
-	TruthValue getNullable();
+	Boolean getNullable();
 
 	/**
 	 * The JDBC type-code.

hibernate-core/src/main/java/org/hibernate/tool/schema/extract/spi/ColumnTypeInformation.java

@@ -7,7 +7,6 @@ package org.hibernate.tool.schema.extract.spi;
 import java.sql.Types;
 
 import org.hibernate.Incubating;
-import org.hibernate.boot.model.TruthValue;
 
 /**
  * Provides access to information about existing table columns
@@ -20,8 +19,8 @@ public interface ColumnTypeInformation {
 
 	ColumnTypeInformation EMPTY = new ColumnTypeInformation() {
 		@Override
-		public TruthValue getNullable() {
+		public Boolean getNullable() {
-			return TruthValue.UNKNOWN;
+			return null;
 		}
 
 		@Override
@@ -46,11 +45,13 @@ public interface ColumnTypeInformation {
 	};
 
 	/**
-	 * Is the column nullable.  The database is allowed to report unknown, hence the use of TruthValue
+	 * Is the column nullable.
+	 * <p>
+	 * The database is allowed to report unknown, hence the use of {@link Boolean}.
 	 *
-	 * @return nullability.
+	 * @return nullability, if known
 	 */
-	TruthValue getNullable();
+	Boolean getNullable();
 
 	/**
 	 * The JDBC type-code.

hibernate-core/src/main/java/org/hibernate/type/descriptor/jdbc/spi/JdbcTypeRegistry.java

@@ -10,7 +10,6 @@ import java.util.Locale;
 import java.util.Objects;
 import java.util.concurrent.ConcurrentHashMap;
 
-import org.hibernate.boot.model.TruthValue;
 import org.hibernate.dialect.Dialect;
 import org.hibernate.metamodel.mapping.EmbeddableMappingType;
 import org.hibernate.metamodel.spi.RuntimeModelCreationContext;
@@ -165,7 +164,7 @@ public class JdbcTypeRegistry implements JdbcTypeBaseline.BaselineTarget, Serial
 			registrationKey = null;
 		}
 		final JdbcType descriptor = getDescriptor( jdbcTypeCode );
-		if ( !( descriptor instanceof AggregateJdbcType ) ) {
+		if ( !(descriptor instanceof AggregateJdbcType aggregateJdbcType) ) {
 			throw new IllegalArgumentException(
 					String.format(
 							"Tried to resolve the JdbcType [%s] as AggregateJdbcType but it does not implement that interface!",
@@ -173,7 +172,6 @@ public class JdbcTypeRegistry implements JdbcTypeBaseline.BaselineTarget, Serial
 					)
 			);
 		}
-		final AggregateJdbcType aggregateJdbcType = (AggregateJdbcType) descriptor;
 		final AggregateJdbcType resolvedJdbcType = aggregateJdbcType.resolveAggregateJdbcType(
 				embeddableMappingType,
 				typeName,
@@ -181,8 +179,7 @@ public class JdbcTypeRegistry implements JdbcTypeBaseline.BaselineTarget, Serial
 		);
 		if ( registrationKey != null ) {
 			aggregateDescriptorMap.put( registrationKey, resolvedJdbcType );
-			if ( resolvedJdbcType instanceof SqlTypedJdbcType ) {
+			if ( resolvedJdbcType instanceof SqlTypedJdbcType sqlTypedJdbcType ) {
-				final SqlTypedJdbcType sqlTypedJdbcType = (SqlTypedJdbcType) resolvedJdbcType;
 				sqlTypedDescriptorMap.put( sqlTypedJdbcType.getSqlTypeName().toLowerCase( Locale.ROOT ), sqlTypedJdbcType );
 			}
 		}
@@ -295,7 +292,7 @@ public class JdbcTypeRegistry implements JdbcTypeBaseline.BaselineTarget, Serial
 	private static final class TypeConstructedJdbcTypeKey {
 		private final int typeConstructorTypeCode;
 		private final Object jdbcTypeOrBasicType;
-		private final TruthValue nullable;
+		private final Boolean nullable;
 		private final int typeCode;
 		private final @Nullable String typeName;
 		private final int columnSize;
@@ -308,7 +305,7 @@ public class JdbcTypeRegistry implements JdbcTypeBaseline.BaselineTarget, Serial
 			this.typeConstructorTypeCode = typeConstructorTypeCode;
 			this.jdbcTypeOrBasicType = jdbcTypeOrBasicType;
 			if ( columnTypeInformation == null ) {
-				this.nullable = TruthValue.UNKNOWN;
+				this.nullable = null;
 				this.typeCode = Types.OTHER;
 				this.typeName = null;
 				this.columnSize = 0;

hibernate-core/src/test/java/org/hibernate/orm/test/tool/schema/internal/CheckForExistingForeignKeyTest.java

@@ -11,7 +11,6 @@ import java.util.List;
 import java.util.Set;
 
 import org.hibernate.boot.Metadata;
-import org.hibernate.boot.model.TruthValue;
 import org.hibernate.boot.model.naming.Identifier;
 import org.hibernate.boot.model.relational.Namespace;
 import org.hibernate.boot.model.relational.Namespace.Name;
@@ -362,9 +361,7 @@ public class CheckForExistingForeignKeyTest {
 		String typeName = null;
 		int columnSize = 0;
 		int decimalDigits = 0;
-		TruthValue nullable = null;
+		return new ColumnInformationImpl( containingTableInformation, columnIdentifier, typeCode, typeName, columnSize,
-		ColumnInformationImpl columnInformation = new ColumnInformationImpl( containingTableInformation, columnIdentifier, typeCode, typeName, columnSize,
+				decimalDigits, null );
-				decimalDigits, nullable );
-		return columnInformation;
 	}
 }

hibernate-core/src/test/java/org/hibernate/tool/schema/internal/AbstractSchemaMigratorTest.java

@@ -8,7 +8,6 @@ import java.util.ArrayList;
 import java.util.Set;
 
 import org.hibernate.boot.Metadata;
-import org.hibernate.boot.model.TruthValue;
 import org.hibernate.boot.model.naming.Identifier;
 import org.hibernate.boot.model.relational.Namespace;
 import org.hibernate.boot.model.relational.QualifiedTableName;
@@ -62,8 +61,8 @@ public class AbstractSchemaMigratorTest {
 				.when(destinationTableInformation).getName();
 		columnReferenceMappings.add(new ForeignKeyInformationImpl.ColumnReferenceMappingImpl(
 				new ColumnInformationImpl(null, toIdentifier("referencing_column"), // column name is lower case
-						0, "typeName", 255, 0, TruthValue.TRUE),
+						0, "typeName", 255, 0, true),
-				new ColumnInformationImpl(destinationTableInformation, null, 1, "typeName", 0, 0, TruthValue.TRUE)));
+				new ColumnInformationImpl(destinationTableInformation, null, 1, "typeName", 0, 0, true)));
 		doReturn(singletonList(new ForeignKeyInformationImpl(toIdentifier("FKp8mpamfw2inhj88hwhty1eipm"), columnReferenceMappings)))
 				.when(existingTableInformation).getForeignKeys();