[Feature] [Style] Add Spotless plugin to fix formatting and style errors automatically

[EricGao888]

Purpose of this pull request

• Replaced Checkstyle and Scala Style with Spotless to fix formatting and style errors automatically
• Gave examples on style fix of .java, .md, .scala files.
• Updated related docs.
• This PR closes: [Feature][Style] Use Spotless to fix formatting and style errors automatically #2492

Check list

• Code changed are covered with tests, or it does not need tests for reason:
• If any new Jar binary package adding in your PR, please add License Notice according
  New License Guide
• If necessary, please update the documentation to describe the new feature. https://github.com/apache/incubator-seatunnel/tree/dev/docs

[EricJoy2048]

This is a very helpful feature for us. @531651225 @legendtkl @TyrantLucifer @laglangyue @getChan @2013650523 @TaoZex @liugddx PTAL.

[ashulin]

Can scala be added?
And change the file name to seatunnel.importorder

[EricGao888]

Thanks for the suggestions. I will take a look and see whether we could add scala into it.

[hailin0]

great

[EricGao888]

@ashulin Sorry for the late update, I add extra configurations for scala formatting configurations and rename the previous eclipse.importorder to seatunnel.importorder. BTW, I found there are lot of suppressions related to checkstyle, I suppose I need to remove them as well?

https://github.com/apache/incubator-seatunnel/blob/dev/tools/checkstyle/suppressions.xml
https://github.com/apache/incubator-seatunnel/blob/c29370a7b5bf6d70e4266b4b4b345e059a699148/seatunnel-connectors-v2/connector-elasticsearch/src/main/java/org/apache/seatunnel/connectors/seatunnel/elasticsearch/client/EsRestClient.java#L51

[EricJoy2048]

@ashulin PTAL

[FlechazoW]

Hi, @EricGao888 Is there any process here? If this is not convenient for you, I can continue to do this.

[EricGao888]

Hi, @EricGao888 Is there any process here? If this is not convenient for you, I can continue to do this.

Hello @FlechazoW , thanks for reaching out. Recently I've been quite busy with something else. I would appreciated it if you could help continue to complete this work. BTW, the configuration of ratchetFrom in this PR may not function as expected. You may refer to diffplug/spotless#710 (comment) for a workaround. If possible, I suggest not using ratchetFrom but fixing the legacy formatting errors once for all.

[FlechazoW]

Hi, @EricGao888 Is there any process here? If this is not convenient for you, I can continue to do this.

Hello @FlechazoW , thanks for reaching out. Recently I've been quite busy with something else. I would appreciated it if you could help continue to complete this work. BTW, the configuration of ratchetFrom in this PR may not function as expected. You may refer to diffplug/spotless#710 (comment) for a workaround. If possible, I suggest not using ratchetFrom and fix the legacy formatting errors once for all.

Thanks for your advice, and I will perfect this as much as possible.

[EricGao888]

Closed due to #2641 (comment)