[FLINK-17537][connectors / jdbc] Refactor flink-jdbc connector structure

[leonardBang]

What is the purpose of the change

• This pull request refactor flink-jdbc connector structure and make it align with others in connector family. I split the PR to two commits to keep them clear enough.

Brief change log

commit: 6aff2b5

(1) Use Jdbc instead of JDBC;
(2) Move interfaces and classes to org.apache.flink.connector.jdbc;
(3) Keep ancient JDBCOutputFormat, JDBCInputFormat and ParameterValuesProvider in old package;
(4) Add tests/ITCase for ancient Classes and new classes.

commit: 173ded8

(1) Rename flink-jdbc module to flink-connector-jdbc;
(2) Update docs.

Verifying this change

• Add tests for reserved class in old package
• Update tests for new package

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (no)
• The serializers: (no)
• The runtime per-record code paths (performance sensitive): ( no)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Yarn/Mesos, ZooKeeper: (no)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? (no)
• If yes, how is the feature documented? (not applicable / docs / JavaDocs / not documented)

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Last check on commit 173ded8 (Fri May 08 10:15:17 UTC 2020)

Warnings:

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[fpompermaier]

Just two notes: since you are refactoring the entire JDBC connector I have collected 2 observations from the other PR I have opened:

• made by @aljoscha on pull [FLINK-17361] [jdbc] Added custom query on JDBC tables #11986 for FLINK-17361: the usage of StreamITCase.clear() in JDBCTableSourceITCase.java is an anti-pattern that should be avoided
• made by me on pull [FLINK-14101][jdbc] Added MS SQL-server dialect #12038 and [FLINK-14100][jdbc] Added Oracle dialect #11999: in all methods in JDBCDialect.java it would be better to have the tableName parameter as an object on which we can extract schema and the non-qualified tableName, in order to avoid to wrongly quote table names. In those PR I removed the quoteIdentifier(tableName) within the getMergeIntoStatement() but I think the same principle applies also to other methods such as getInsertIntoStatement() or getRowExistsStatement().

[wuchong]

Thanks fro the contribution @leonardBang . I left some comments.

[leonardBang]

Thanks @faisalmoeen and @wuchong ‘s notes and comments.
I'll update the PR soon.
Hi, @fpompermaier For your first note about StreamITCase.clear() I‘ll skip too because FLIP-84 is not ready now(but should be soon). For the second note, this PR will try not to modify JDBCDDialect.java and keep the PR clean and I think the JDBC Dialect need a better design too but not in this time(It will be a public API and need disscuss and design and even a FLIP from my unserstanding)

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CI report:

• 72118ce Azure: FAILURE
• 1cd4217 Azure: PENDING

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[leonardBang]

squash to one commit for merge

[wuchong]

Thanks for the great work. LGTM.

[wuchong]

@flinkbot run azure

[leonardBang]

@flinkbot run azure

[leonardBang]

rebase master to fix minor conflict
@flinkbot run azure

[wuchong]

Merging...