根据状态分组
//原来写法
Map<String, WmSoDetail> upDetailMap = upWmSoDetailList.stream().collect(Collectors.toMap(WmSoDetail::getStatus, item -> item));
//正确写法
Map<String, WmSoDetail> upDetailMap = upWmSoDetailList.stream().collect(Collectors.toMap(WmSoDetail::getStatus, item -> item,(k1, k2) -> k1));
jdk 8 list 转map Duplicate key WmSoDetail
原文：https://www.cnblogs.com/lanliying/p/15183463.html