HDDS-14104. Refactor RequestContext creation

[Russole]

What changes were proposed in this pull request?

Refactored RequestContext to use a builder-only construction pattern.

• Removed multiple public constructors and redundant getBuilder helpers from RequestContext.
• Adopted builder-only construction by making the Builder constructor private.
• Declared RequestContext and its Builder as final.
• Updated tests to use RequestContext.newBuilder().

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-14104

How was this patch tested?

All CI checks passed.

[adoroszlai]

Thanks @Russole for the patch. The change in RequestContext looks good. TestRequestContext can be simplified.

[adoroszlai]

nit: null is the default value in the builder for these properties, so this can be removed.

Suggested change

	.setIp(null)
	.setHost(null)

[adoroszlai]

Looks like testSessionPolicy() has been testing sessionPolicy for various ways of creating RequestContext. Now constructor is private and getBuilder no longer exists, so all variants are testing the builder. We can remove the parts that perform duplicate verifications, and simplify this to:

@TestvoidtestSessionPolicy() {
RequestContext.Builderbuilder = RequestContext.newBuilder();
assertNull(builder.build().getSessionPolicy(), "default value");
finalStringpolicy = "{\"Statement\":[]}";
builder.setSessionPolicy(policy);
assertEquals(policy, builder.build().getSessionPolicy());
}

[adoroszlai]

testRecursiveAccessFlag() has also been testing constructor, builder and getBuilder. Now there are only 3 possible combinations:

• default value (without explicit setRecursiveAccessCheck)
• setRecursiveAccessCheck(false)
• setRecursiveAccessCheck(true)

So we can simplify this test case further:

@TestvoidtestRecursiveAccessFlag() {
RequestContext.Builderbuilder = RequestContext.newBuilder();
assertFalse(builder.build().isRecursiveAccessCheck(), "default value");
builder.setRecursiveAccessCheck(true);
assertTrue(builder.build().isRecursiveAccessCheck());
builder.setRecursiveAccessCheck(false);
assertFalse(builder.build().isRecursiveAccessCheck());
}

getUserRequestContext() and baseBuilder() can be removed, as well as unused imports.

[Russole]

Thanks @adoroszlai for the review and suggestions.

[adoroszlai]

Thanks @Russole for updating the patch.