StringUtils (org.apache.commons.lang3.StringUtils) 中的常用方法

isNotBlank

if (StringUtils.isNotBlank(key)) {
    criteria.orLike("title", "%" + key + "%");
}

join

List<String> names = categories.stream().map(Category::getName).collect(Collectors.toList());
String name = StringUtils.join(names, " ");

substringBefore

StringUtils.substringBefore(sku.getImages(), ",")