优化这段代码：if (constructionCompanyVo.getProjectCodeList() != null && constructionCompanyVo.getProjectCodeList().size() > 0) { constructionCompany.setProjectCode(String.join(",", constructionCompanyVo.getProjectCodeList())); constructionCompany.setProjectName(String.join(",", constructionCompanyVo.getProjectNameList())); }

可以优化的地方有：

1. 使用 Optional 类简化代码：

Optional.ofNullable(constructionCompanyVo.getProjectCodeList())
    .filter(list -> !list.isEmpty())
    .ifPresent(list -> {
        constructionCompany.setProjectCode(String.join(",", list));
        constructionCompany.setProjectName(String.join(",", constructionCompanyVo.getProjectNameList()));
    });

2. 使用 StringUtils 类简化代码：

if (ArrayUtils.isNotEmpty(constructionCompanyVo.getProjectCodeList())) {
    constructionCompany.setProjectCode(StringUtils.join(constructionCompanyVo.getProjectCodeList(), ","));
    constructionCompany.setProjectName(StringUtils.join(constructionCompanyVo.getProjectNameList(), ","));
}

这里使用了 Apache Commons Lang3 库中的 ArrayUtils 和 StringUtils 类。