throw CoercionException when CharacterJavaType receives a string of w…

…rong length

Signed-off-by: Gavin King <gavin@hibernate.org>

hibernate-core/src/main/java/org/hibernate/type/descriptor/java/CharacterJavaType.java

@@ -36,7 +36,7 @@ public String toString(Character value) {
 	@Override
 	public Character fromString(CharSequence string) {
 		if ( string.length() != 1 ) {
-			throw new HibernateException( "multiple or zero characters found parsing string" );
+			throw new CoercionException( "value must contain exactly one character: '" + string + "'" );
 		}
 		return string.charAt( 0 );
 	}
@@ -68,12 +68,10 @@ public <X> Character wrap(X value, WrapperOptions options) {
 			return character;
 		}
 		if (value instanceof String string) {
-			// Note that this conversion is "dangerous",
-			// since it is not invertible, and can in
-			// principle result in accidental loss of data.
-			// It might be better to throw if the incoming
-			// string does not have length one.
-			return string.isEmpty() ? null : string.charAt( 0 );
+			if ( string.length() != 1 ) {
+				throw new CoercionException( "value must contain exactly one character: '" + string + "'" );
+			}
+			return string.charAt( 0 );
 		}
 		if (value instanceof Number number) {
 			return (char) number.shortValue();

hibernate-core/src/main/java/org/hibernate/type/descriptor/java/CoercionException.java

@@ -7,6 +7,8 @@
 import org.hibernate.HibernateException;
 
 /**
+ * A problem converting between JDBC types and Java types.
+ *
  * @author Steve Ebersole
  */
 public class CoercionException extends HibernateException {