GitHub user bowenli86 opened a pull request:
https://github.com/apache/flink/pull/4663
[FLINK-6549] [DataStream API] Improve error message for type mismatches
with side outputs
## What is the purpose of the change
A type mismatch when using side outputs causes a ClassCastException to be
thrown. It would be neat to include the name of the `OutputTag`s in the
exception message.
This can occur when multiple `OutputTag`s with different types but
identical names are being used.
## Brief change log
With this change, ClassCastException will be caught separately. We will
replace it with a new one that has enriched error message. The enriched error
message will have `OutputTag`'s id, and a brief explanation of why this error
may occur.
## Verifying this change
This change is a trivial rework / code cleanup without any test coverage.
The new error message looks like this:
```
Caused by: java.lang.ClassCastException: java.lang.Integer cannot be cast
to java.lang.String. Failed to push OutputTag with id 'mytag' to operator. This
can occur when multiple OutputTags with different types but identical names are
being used.
```
## Does this pull request potentially affect one of the following parts:
## Documentation
- Does this pull request introduce a new feature? (no)
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/bowenli86/flink FLINK-6549
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/4663.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #4663
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commit 6386983239bd3024b395c865ec4fd33e232ca5a3
Author: Bowen Li <bowenl...@gmail.com>
Date: 2017-08-30T16:35:03Z
FLINK-7422 Upgrade Kinesis Client Library (KCL) and AWS SDK in
flink-connector-kinesis
commit 381cd4156b84673a1d32d2db3f7b2d748d90d980
Author: Bowen Li <bowenl...@gmail.com>
Date: 2017-09-07T06:33:37Z
Merge remote-tracking branch 'upstream/master'
commit 3e60bc63fc1a9c884bdf3d3bd2fe869c1c631849
Author: Bowen Li <bowenl...@gmail.com>
Date: 2017-09-09T07:03:13Z
FLINK-6549 Improve error message for type mismatches with side outputs
commit c55adb7a4b1bd224b0578f0bad583fa58a42b3ae
Author: Bowen Li <bowenl...@gmail.com>
Date: 2017-09-09T07:06:17Z
add comment
commit dc2e68202f7ba063fa8f2a0ea22cbe9de55f95b8
Author: Bowen Li <bowenl...@gmail.com>
Date: 2017-09-09T07:14:34Z
fix grammer
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