Clarify behaviour of reusing JsonObjectBuilder#build()

[glassfishrobot]

In short: is the JsonObjectBuilder#build() method meant to be reusable?

And if I reuse it, does it's internal data gets cleaned when build() is invoked?

final JsonObjectBuilder builder = Json.createObjectBuilder();
builder.add("a", "b");
JsonObject jsonObject = builder.build();
assertEquals("{\"a\":\"b\"}", jsonObject.toString());

builder.add("c", "d");
JsonObject bigQuestionmark = builder.build();

What does the bigQuestionmark JsonObject contain?

{"c":"d"}

or

{"a":"b","c":"d"}

or does it blow up?

Affected Versions

[1.0-pr]

[glassfishrobot]

Reported by struberg

[glassfishrobot]

rmannibucau said:
+1 for the exception, for objects it would be weird to overwrite a value but for arrays it is worse since you can't step back. There was a mutable proposal at some time which would better fit this use case than the original builders IMHO

[glassfishrobot]

struberg said:
Not sure about that.

There are 2 other method

JsonObjectBuilder add(String name, JsonObjectBuilder builder);
JsonObjectBuilder add(String name, JsonArrayBuilder builder);

so if using the builder would 'consume' and invalidate the builder, then those methods would be pretty much useless?

Think about having something like:

JsonObjectBuilder personBuilder = ...;
JsonObjectBuilder usage = ..;

usage.add("createdBy", personBuilder);
usage.add("modifiedBy", personBuilder);

Btw, we also need to define the behaviour for JsonArrayBuilder.

[glassfishrobot]

@m0mus said:
It can be reused. It will return a new object containing

{"a":"b","c":"d"}

in your use case. It looks clear for me.

[glassfishrobot]

Marked as works as designed on Monday, March 6th 2017, 8:23:14 am

[glassfishrobot]

struberg said:
We do not need to change any API, but it's imo not clear from the API wording.

[glassfishrobot]

This issue was imported from java.net JIRA JSON_PROCESSING_SPEC-84