记一次Optional导致的 java.util.NoSuchElementException: No value present

在跑任务的时候，代码

Optional comSizeMaxCompanyComSizeBean  = entrySet.getValue().stream()
                        .filter(bean -> bean.getComSizeMax() >= finalComSizeMin)
                        .collect(Collectors.minBy(Comparator.comparing(CompanyComSizeBean::getComSizeMax)));

                if(comSizeMaxCompanyComSizeBean != null ){
                    CompanyComSizeBean companyComSizeBean = comSizeMaxCompanyComSizeBean.get();
                    comSizeMax = companyComSizeBean.getComSizeMin();
                }

出现以下异常：

java.util.NoSuchElementException: No value present
	at java.util.Optional.get(Optional.java:135)

经查询博客Java 8 Optional类深度解析发现，究其原因为： 

//在空的Optional实例上调用get()，抛出NoSuchElementException

更正代码如下：

Optional comSizeMaxCompanyComSizeBean  = entrySet.getValue().stream()
                        .filter(bean -> bean.getComSizeMax() >= finalComSizeMin)
                        .collect(Collectors.minBy(Comparator.comparing(CompanyComSizeBean::getComSizeMax)));

                if(comSizeMaxCompanyComSizeBean != null && comSizeMaxCompanyComSizeBean.isPresent()){
                    CompanyComSizeBean companyComSizeBean = comSizeMaxCompanyComSizeBean.get();
                    comSizeMax = companyComSizeBean.getComSizeMin();
                }

查询博客地址：https://www.cnblogs.com/xingzc/p/5778090.html