EntityUtils.java 文件源码

private static void collectIdNamesFromFields(final List<String> idList, final Class<?> clazz) {
    for (final Field field : clazz.getDeclaredFields()) {
        if (field.getAnnotation(Id.class) != null) {
            idList.add(getPropertyName(field));
        } else if (field.getAnnotation(EmbeddedId.class) != null) {
            final Class<?> fieldType = field.getType();
            // all fields have to be used as a composite ID
            for (final Field idField : fieldType.getDeclaredFields()) {
                idList.add(field.getName() + "." + getPropertyName(idField));
            }
        }
    }
}