MyBatis mapper to insert annotation with reflection

I have the below MyBatis Mapper with an insertion method:

String INSERT =SQLUtil.getFields(Consumer.class);
String INSERT_WITH_BRACE = SQLUtil.GetFieldsWithBrace(Consumer.class);
@Insert("INSERT INTO Consumer("+ INSERT  +") " +
        " VALUES " + INSERT_WITH_BRACE)

public int insert(Consumer consumer);

The idea is to generate boiler-plate code using SQLUtil; a utility class which has two static methods.

@Component
public class SQLUtil {
    private static StringBuilder stringBuilder;
    public static String getFields(Class clazz) {
        stringBuilder = new StringBuilder();
        Field[] declaredFields = clazz.getDeclaredFields();
        int pos = 0;
        for(Field field: declaredFields){
            stringBuilder.append(field.getName());
            if(pos++ < declaredFields.length-1)
                stringBuilder.append(",");
        }
        return stringBuilder.toString();
    }

    public static String GetFieldsWithBrace(Class clazz) {
        int i=0;
        stringBuilder = new StringBuilder();
        Field[] declaredFields = clazz.getDeclaredFields();
        for(Field field: declaredFields){
            stringBuilder.append("#{");
            stringBuilder.append(field.getName());
            stringBuilder.append("}");
            if(i++ < declaredFields.length-1)
                stringBuilder.append(",");
        }
        return stringBuilder.toString();
    }
}

Here I utilize reflection to retrieve all properties from a specific class returning the boiler-plate mapper. But I have the error message "attribute must be Constant". I really don't want to write those properties on my own. How can I solve this?