[jira] [Resolved] (HADOOP-13191) FileSystem#listStatus should not return null

2016-09-07 Thread John Zhuge (JIRA) 

 [ 
https://issues.apache.org/jira/browse/HADOOP-13191?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

John Zhuge resolved HADOOP-13191.
-
Resolution: Duplicate

> FileSystem#listStatus should not return null
> 
>
> Key: HADOOP-13191
> URL: https://issues.apache.org/jira/browse/HADOOP-13191
> Project: Hadoop Common
>  Issue Type: Bug
>  Components: fs
>Affects Versions: 2.6.0
>Reporter: John Zhuge
>Assignee: John Zhuge
>Priority: Minor
> Attachments: HADOOP-13191.001.patch, HADOOP-13191.002.patch, 
> HADOOP-13191.003.patch, HADOOP-13191.004.patch
>
>
> This came out of discussion in HADOOP-12718. The {{FileSystem#listStatus}} 
> contract does not indicate {{null}} is a valid return and some callers do not 
> test {{null}} before use:
> AbstractContractGetFileStatusTest#testListStatusEmptyDirectory:
> {code}
> assertEquals("ls on an empty directory not of length 0", 0,
> fs.listStatus(subfolder).length);
> {code}
> ChecksumFileSystem#copyToLocalFile:
> {code}
>   FileStatus[] srcs = listStatus(src);
>   for (FileStatus srcFile : srcs) {
> {code}
> SimpleCopyLIsting#getFileStatus:
> {code}
>   FileStatus[] fileStatuses = fileSystem.listStatus(path);
>   if (excludeList != null && excludeList.size() > 0) {
> ArrayList fileStatusList = new ArrayList<>();
> for(FileStatus status : fileStatuses) {
> {code}
> IMHO, there is no good reason for {{listStatus}} to return {{null}}. It 
> should throw IOExceptions upon errors or return empty list.
> To enforce the contract that null is an invalid return, update javadoc and 
> leverage @Nullable/@NotNull/@Nonnull annotations.
> So far, I am only aware of the following functions that can return null:
> * RawLocalFileSystem#listStatus



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

-
To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: common-issues-h...@hadoop.apache.org

[jira] [Resolved] (HADOOP-13191) FileSystem#listStatus should not return null

2016-05-24 Thread John Zhuge (JIRA) 

 [ 
https://issues.apache.org/jira/browse/HADOOP-13191?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

John Zhuge resolved HADOOP-13191.
-
Resolution: Duplicate

Thanks [~boky01], it is a dup of HADOOP-7352.

One idea is to add {{@NotNull}} to {{FileSystem#listStatus}}:
{code}
  @NotNull
  public abstract FileStatus[] listStatus(Path f) throws IOException;
{code}

Then run IntelliJ - Analyze - "Run Inspection by Name ..." - 
"@NotNull/@Nullible problems" (multiple times if necessary) in order to:
* Propagate {{@NotNull}} to subclasses' {{listStatus}} method
* Detect any implementation of {{listStatus}} that may return {{null}}

> FileSystem#listStatus should not return null
> 
>
> Key: HADOOP-13191
> URL: https://issues.apache.org/jira/browse/HADOOP-13191
> Project: Hadoop Common
>  Issue Type: Bug
>  Components: fs
>Affects Versions: 2.6.0
>Reporter: John Zhuge
>Assignee: John Zhuge
>Priority: Minor
>
> This came out of discussion in HADOOP-12718. The {{FileSystem#listStatus}} 
> contract does not indicate {{null}} is a valid return and some callers do not 
> test {{null}} before use:
> AbstractContractGetFileStatusTest#testListStatusEmptyDirectory:
> {code}
> assertEquals("ls on an empty directory not of length 0", 0,
> fs.listStatus(subfolder).length);
> {code}
> ChecksumFileSystem#copyToLocalFile:
> {code}
>   FileStatus[] srcs = listStatus(src);
>   for (FileStatus srcFile : srcs) {
> {code}
> SimpleCopyLIsting#getFileStatus:
> {code}
>   FileStatus[] fileStatuses = fileSystem.listStatus(path);
>   if (excludeList != null && excludeList.size() > 0) {
> ArrayList fileStatusList = new ArrayList<>();
> for(FileStatus status : fileStatuses) {
> {code}
> IMHO, there is no good reason for {{listStatus}} to return {{null}}. It 
> should return empty list instead.
> To enforce the contract that null is an invalid return, update javadoc and 
> consider Intellij IDEA's @Nullable and @NotNull annotations.
> So far, I am only aware of the following functions that can return null:
> * RawLocalFileSystem#listStatus



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

-
To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: common-issues-h...@hadoop.apache.org