various cleanups

documentation/src/main/asciidoc/introduction/Configuration.adoc

@@ -503,10 +503,11 @@ We'll have more to say about them in <<naming-strategies>>.
 [[quoted-identifiers]]
 === Quoting SQL identifiers
 
-By default, Hibernate never quotes SQL table and column names in generated SQL.
+By default, Hibernate never quotes a SQL table or column name in generated SQL when the name contains only alphanumeric characters.
 This behavior is usually much more convenient, especially when working with a legacy schema, since unquoted identifiers aren't case-sensitive, and so Hibernate doesn't need to know or care whether a column is named `NAME`, `name`, or `Name` on the database side.
+On the other hand, any table or column name containing a punctuation character like `$` is automatically quoted by default.
 
-The following settings enable automatic quoting:
+The following settings enable additional automatic quoting:
 
 .Settings for identifier quoting
 [%breakable,cols="35,~"]

hibernate-core/src/main/java/org/hibernate/boot/model/naming/DatabaseIdentifier.java

@@ -4,7 +4,7 @@
  */
 package org.hibernate.boot.model.naming;
 
-import org.hibernate.internal.util.StringHelper;
+import static org.hibernate.internal.util.StringHelper.isEmpty;
 
 /**
  * Models an identifier (name), retrieved from the database.
@@ -24,13 +24,13 @@ protected DatabaseIdentifier(String text) {
 	}
 
 	public static DatabaseIdentifier toIdentifier(String text) {
-		if ( StringHelper.isEmpty( text ) ) {
+		if ( isEmpty( text ) ) {
 			return null;
 		}
 		else if ( isQuoted( text ) ) {
 			// exclude the quotes from text
-			final String unquotedtext = text.substring( 1, text.length() - 1 );
-			return new DatabaseIdentifier( unquotedtext );
+			final String unquoted = text.substring( 1, text.length() - 1 );
+			return new DatabaseIdentifier( unquoted );
 		}
 		else {
 			return new DatabaseIdentifier( text );

hibernate-core/src/main/java/org/hibernate/boot/model/naming/Identifier.java

@@ -7,9 +7,12 @@
 import java.util.Locale;
 
 import org.hibernate.dialect.Dialect;
-import org.hibernate.internal.util.StringHelper;
 
+import static java.lang.Character.isLetter;
+import static java.lang.Character.isLetterOrDigit;
+import static java.lang.Character.isWhitespace;
 import static org.hibernate.internal.util.StringHelper.isBlank;
+import static org.hibernate.internal.util.StringHelper.isEmpty;
 
 /**
  * Models an identifier (name), which may or may not be quoted.
@@ -83,13 +86,13 @@ public static Identifier toIdentifier(String text, boolean quote, boolean quoteO
 		int start = 0;
 		int end = text.length();
 		while ( start < end ) {
-			if ( !Character.isWhitespace( text.charAt( start ) ) ) {
+			if ( !isWhitespace( text.charAt( start ) ) ) {
 				break;
 			}
 			start++;
 		}
 		while ( start < end ) {
-			if ( !Character.isWhitespace( text.charAt( end - 1 ) ) ) {
+			if ( !isWhitespace( text.charAt( end - 1 ) ) ) {
 				break;
 			}
 			end--;
@@ -102,14 +105,14 @@ public static Identifier toIdentifier(String text, boolean quote, boolean quoteO
 		else if ( quoteOnNonIdentifierChar && !quote ) {
 			// Check the letters to determine if we must quote the text
 			char c = text.charAt( start );
-			if ( !Character.isLetter( c ) && c != '_' ) {
+			if ( !isLetter( c ) && c != '_' ) {
 				// SQL identifiers must begin with a letter or underscore
 				quote = true;
 			}
 			else {
 				for ( int i = start + 1; i < end; i++ ) {
 					c = text.charAt( i );
-					if ( !Character.isLetterOrDigit( c ) && c != '_' ) {
+					if ( !isLetterOrDigit( c ) && c != '_' ) {
 						quote = true;
 						break;
 					}
@@ -163,7 +166,7 @@ public static String unQuote(String name) {
 	 * @param quoted Is this a quoted identifier?
 	 */
 	public Identifier(String text, boolean quoted) {
-		if ( StringHelper.isEmpty( text ) ) {
+		if ( isEmpty( text ) ) {
 			throw new IllegalIdentifierException( "Identifier text cannot be null" );
 		}
 		if ( isQuoted( text ) ) {
@@ -234,11 +237,9 @@ public String toString() {
 
 	@Override
 	public boolean equals(Object o) {
-		if ( !(o instanceof Identifier) ) {
+		if ( !(o instanceof Identifier that) ) {
 			return false;
 		}
-
-		final Identifier that = (Identifier) o;
 		return getCanonicalName().equals( that.getCanonicalName() );
 	}