HHH-13496 Declare single char strings as chars

hibernate-core/src/main/java/org/hibernate/boot/archive/internal/JarProtocolArchiveDescriptor.java

@@ -37,7 +37,7 @@ public class JarProtocolArchiveDescriptor implements ArchiveDescriptor {
 		}
 
 		final String urlFile = url.getFile();
-		final int subEntryIndex = urlFile.lastIndexOf( "!" );
+		final int subEntryIndex = urlFile.lastIndexOf( '!' );
 		if ( subEntryIndex == -1 ) {
 			throw new AssertionFailure( "JAR URL does not contain '!/' :" + url );
 		}

hibernate-core/src/main/java/org/hibernate/dialect/SQLServer2012Dialect.java

@@ -58,7 +58,7 @@ public class SQLServer2012Dialect extends SQLServer2008Dialect {
 				sql.length()
 						+ hints.length() + 12
 		);
-		final int pos = sql.indexOf( ";" );
+		final int pos = sql.indexOf( ';' );
 		if ( pos > -1 ) {
 			buffer.append( sql.substring( 0, pos ) );
 		}

hibernate-core/src/main/java/org/hibernate/engine/jdbc/connections/spi/DataSourceBasedMultiTenantConnectionProviderImpl.java

@@ -92,7 +92,7 @@ public class DataSourceBasedMultiTenantConnectionProviderImpl
 		}
 
 		if ( DataSource.class.isInstance( namedObject ) ) {
-			final int loc = jndiName.lastIndexOf( "/" );
+			final int loc = jndiName.lastIndexOf( '/' );
 			this.baseJndiNamespace = jndiName.substring( 0, loc );
 			this.tenantIdentifierForAny = jndiName.substring( loc + 1 );
 			dataSourceMap().put( tenantIdentifierForAny, (DataSource) namedObject );

hibernate-core/src/main/java/org/hibernate/internal/util/StringHelper.java

@@ -378,12 +378,12 @@ public final class StringHelper {
 	}
 
 	public static String root(String qualifiedName) {
-		int loc = qualifiedName.indexOf( "." );
+		int loc = qualifiedName.indexOf( '.' );
 		return ( loc < 0 ) ? qualifiedName : qualifiedName.substring( 0, loc );
 	}
 
 	public static String unroot(String qualifiedName) {
-		int loc = qualifiedName.indexOf( "." );
+		int loc = qualifiedName.indexOf( '.' );
 		return ( loc < 0 ) ? qualifiedName : qualifiedName.substring( loc + 1, qualifiedName.length() );
 	}