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mingleizhang edited comment on FLINK-6493 at 7/13/17 2:29 AM: -------------------------------------------------------------- Actually, Sorry. I dont think null check is ineffective, as it just combination with another clause which belongs to not empty constructor has {{Preconditions.checkNotNull}}. In empty constructor, it does not have a null check. Even though,it would be still throw an NPE when call {{partitionStateSerializer.equals()}} if {{partitionStateSerializer}} is null and {{((Snapshot) obj).getPartitionStateSerializer() == null}} return a false. So, I believe in this case, we should return a false instead of throw an NPE. was (Author: mingleizhang): Actually, Sorry. I dont think null check is ineffective, as it just combination with another clause which belongs to not empty constructor has {{Preconditions.checkNotNull}}. In empty constructor, it does not have a null check. Even though,it would be still throw an NPE when call {{partitionStateSerializer.equals()}} if {{partitionStateSerializer}} is null and {{((Snapshot) obj).getPartitionStateSerializer() == null}} return a false. So, I believe in this case, we should return a false instead throw an NPE. > Ineffective null check in RegisteredOperatorBackendStateMetaInfo#equals() > ------------------------------------------------------------------------- > > Key: FLINK-6493 > URL: https://issues.apache.org/jira/browse/FLINK-6493 > Project: Flink > Issue Type: Bug > Components: State Backends, Checkpointing > Reporter: Ted Yu > Assignee: mingleizhang > Priority: Minor > > {code} > && ((partitionStateSerializer == null && ((Snapshot) > obj).getPartitionStateSerializer() == null) > || partitionStateSerializer.equals(((Snapshot) > obj).getPartitionStateSerializer())) > && ((partitionStateSerializerConfigSnapshot == null && ((Snapshot) > obj).getPartitionStateSerializerConfigSnapshot() == null) > || partitionStateSerializerConfigSnapshot.equals(((Snapshot) > obj).getPartitionStateSerializerConfigSnapshot())); > {code} > The null check for partitionStateSerializer / > partitionStateSerializerConfigSnapshot is in combination with another clause. > This may lead to NPE in the partitionStateSerializer.equals() call. -- This message was sent by Atlassian JIRA (v6.4.14#64029)