java.lang.IllegalStateException: Duplicate key ex-qixuie002

map中存在key值相同的数据

?

1 2 3

Map<String, String> collect = oList.stream().collect(                 Collectors.toMap(OcmCustomerIdDO::getOcmCustId, info -> info.getUmId() == null ? "" : info.getUmId()));         System.out.println(collect);

　　

 

根据业务逻辑选择，是前者覆盖后者重复，还是后者覆盖前者重复

?

1 2	Map<String, String> collect = oList.stream().collect(                 Collectors.toMap(OcmCustomerIdDO::getOcmCustId, OcmCustomerIdDO::getUmId, (key1, key2) -> key2));//后者覆盖前者