cannot find symbol when compile FE with JDK 12

[kangkaisen]

Describe the bug
The following error will occur when compile FE with JDK 12:

[ERROR] /home/kangkaisen/palo/fe/src/main/java/org/apache/doris/catalog/EsTable.java:[43,22] package javax.xml.soap does not exist
[ERROR] /home/kangkaisen/palo/fe/src/main/java/org/apache/doris/task/LoadPendingTask.java:[41,24] cannot find symbol
  symbol:   class Debug
  location: package sun.security.ssl

I found the sun.security.ssl.Debug is unnecessary. So we could remove it.

Besides, I think we should add a maven-checkstyle-plugin to check FE code style.

[imay]

Besides, I think we should add a maven-checkstyle-plugin to check FE code style.

It's a good idea. Can you help us to add this plugin?

And I think we should discuss about how to use it. For example, what should be checked first.

I'm afraid there will be too many problems if we enable this checker

[kangkaisen]

OK. I could do this work, but I am busy recently. I will do this work when I have time.
Before I do it, I will discuss the detail with you.