HDDS-6208. New checkstyle: WhitespaceAround

[smengcl]

Goal: Enforce whitespace check around symbols.

https://issues.apache.org/jira/browse/HDDS-6208

[smengcl]

@adoroszlai Yes. This huge list of violations is something I want to discuss.

Do you think we should just simply push the xml addition in this PR but ignore those violations (somehow make PR runs only check the diff like Hadoop/HDFS does?), or push all the fixes in this PR?

[smengcl]

@adoroszlai

I have fixed ALL the new WhitespaceAround checkstyle warnings on the latest master branch. Pls take a look.

Apart from that, this PR includes:

1. Checkstyle XML one-line change
2. Print more human readable output with the new sed replacement lines in checkstyle.sh, which was due to XML escape characters in checkstyle-errors.xml files. For example,
   what was:

hadoop-ozone/client/src/main/java/org/apache/hadoop/ozone/client/rpc/RpcClient.java
 540: 'if' is not followed by whitespace.
 859: 'try' is not followed by whitespace.
 859: '{' is not preceded with whitespace.
 953: 'for' is not followed by whitespace.
 959: 'for' is not followed by whitespace.
 1018: 'if' is not followed by whitespace.
 1018: '{' is not preceded with whitespace.
 1160: 'if' is not followed by whitespace.
 1164: '<=' is not followed by whitespace.
 1166: '>=' is not followed by whitespace.
 1511: 'for' is not followed by whitespace.
 1549: 'try' is not followed by whitespace.
 1549: '{' is not preceded with whitespace.
 1553: 'if' is not followed by whitespace.
 1553: '{' is not preceded with whitespace.
 1562: '}' is not followed by whitespace.
 1562: 'catch' is not preceded with whitespace.
 1562: '{' is not preceded with whitespace.

is now:

hadoop-ozone/client/src/main/java/org/apache/hadoop/ozone/client/rpc/RpcClient.java
 540: 'if' is not followed by whitespace.
 859: 'try' is not followed by whitespace.
 859: '{' is not preceded with whitespace.
 953: 'for' is not followed by whitespace.
 959: 'for' is not followed by whitespace.
 1018: 'if' is not followed by whitespace.
 1018: '{' is not preceded with whitespace.
 1160: 'if' is not followed by whitespace.
 1164: '<=' is not followed by whitespace.
 1166: '>=' is not followed by whitespace.
 1511: 'for' is not followed by whitespace.
 1549: 'try' is not followed by whitespace.
 1549: '{' is not preceded with whitespace.
 1553: 'if' is not followed by whitespace.
 1553: '{' is not preceded with whitespace.
 1562: '}' is not followed by whitespace.
 1562: 'catch' is not preceded with whitespace.
 1562: '{' is not preceded with whitespace.

Merging this shouldn't cause too much distruption to existing PRs if any, as those are all straight forward white space additions and are easy to do conflict resolution if it happens.

Preferrably we should review this as soon as possible. It would take longer and longer to merge as new PRs are merged.

Thanks.

[adoroszlai]

Thanks @smengcl for fixing all whitespace issues. I have verified the crux of the change by:

git diff --ignore-all-space $(git merge-base HEAD origin/master)..HEAD

[smengcl]

Thanks @smengcl for fixing all whitespace issues. I have verified the crux of the change by:

git diff --ignore-all-space $(git merge-base HEAD origin/master)..HEAD

Nice! Thanks for the review. Will merge shortly.