Implemented custom duplicate key handling (#840)

[XIAYM-gh]

Supports: throw a JSONException (by default), ignore (not overwritting), overwrite or merge into a JSONArray;
also with tests in a separated file

xD, thanks for reviewing

[XIAYM-gh]

whoa, 2 different errors, working on them

[stleary]

@XIAYM-gh Please discuss the proposed changes in issue #840 before submitting a PR. At this time only throw would be allowed unless you can make a case for the other actions.

[XIAYM-gh]

I can't believe it throws a StackOverFlowError while compiling, should I add a -Xss4M jvm argument to the actions file?

[stleary]

I can't believe it throws a StackOverFlowError while compiling, should I add a -Xss4M jvm argument to the actions file?

It appears to be an intermittent error, only seems to affect Java v11, root cause unknown. After a couple of retries it was successful. Also, the build and test using Java v11 is successful on my laptop. No changes needed at this time.

However, your code is out of date, please merge from the latest master branch.

[XIAYM-gh]

I found the isKeepStrings() method is unused in the JSONParserConfiguration class, should I overwrite the method and throws an UnsupportedOperationException?

[stleary]

I found the isKeepStrings() method is unused in the JSONParserConfiguration class, should I overwrite the method and throws an UnsupportedOperationException?

That method is used by JSONML and XML classes, please don't make any changes to it.

[XIAYM-gh]

I see, thanks!

[stleary]

What problem does this code solve?
Adds an opt-in ability to overwrite a JSONObject duplicate key instead of throwing an exception

Does the code still compile with Java6?
Yes

Risks
Low

Changes to the API?
Yes, new parsing options were added

Will this require a new release?
No

Should the documentation be updated?
No

Does it break the unit tests?
No, new unit tests were added

Was any code refactored in this commit?
No

Review status
APPROVED

Starting 3-day comment window

[stleary]

@XIAYM-gh Please merge from the latest master branch, the PR is not up to date.

[XIAYM-gh]

Oh, I apologize for the late reply, I was just back from school, and I'm sorry for the inconvenience that I've caused

[stleary]

The new JSONParserConfiguration ctor will be removed in a followup commit.