How to remove trailing slash from embedded Jetty URLs?

I use embedded Jetty 9.3.8.v20160314 from Scala (Scala is incidental here, this is a pure Jetty question), configured like this:

val loginService = new RepoLoginService(usersRepository, signInsRepo)

val server = new Server(8080)
server.addBean(loginService)

val security = new ConstraintSecurityHandler()
server.setHandler(security)

val constraint = new Constraint()
constraint.setName("auth")
constraint.setAuthenticate(true)
constraint.setRoles(Array[String]("user", "admin"))

val mapping = new ConstraintMapping()
mapping.setPathSpec("/*")
mapping.setConstraint(constraint)

security.setConstraintMappings(Collections.singletonList(mapping))
security.setAuthenticator(new BasicAuthenticator())
security.setLoginService(loginService)

val mapper = prepareJacksonObjectMapper

val listAccountsController = new ContextHandler("/api/accounts")
listAccountsController.setHandler(new ListAccountsController(mapper, accountsRepository))

val importBankAccountsController = new ContextHandler("/api/bank-account-transactions/import")
importBankAccountsController.setHandler(new ImportBankAccountTransactionsController(mapper, bankAccountTransactionsRepo))

val contexts = new ContextHandlerCollection()
contexts.setHandlers(Array(listAccountsController, importBankAccountsController))

security.setHandler(contexts)

server.start()
server.join()

Notice the context for the listAccountsController: /api/accounts. When I curl /api/accounts, I receive a redirect to /api/accounts/ (note the trailing slash):

$ curl --silent --verbose --user francois:francois http://localhost:8080/api/accounts
*   Trying ::1...
* Connected to localhost (::1) port 8080 (#0)
* Server auth using Basic with user 'francois'
> GET /api/accounts HTTP/1.1
> Host: localhost:8080
> Authorization: Basic ZnJhbmNvaXM6ZnJhbmNvaXM=
> User-Agent: curl/7.43.0
> Accept: */*
>
< HTTP/1.1 302 Found
< Date: Sun, 22 May 2016 03:54:44 GMT
< Location: http://localhost:8080/api/accounts/
< Content-Length: 0
< Server: Jetty(9.3.8.v20160314)
<
* Connection #0 to host localhost left intact

I tried adding a call to clearAliasChecks(), which I'm not sure is even related to this. I also tried changing mapping.setPathSpec("/*") to mapping.setPathSpec("/"), because I read an answer on Tomcat not adding the trailing slash, but this probably doesn't apply to me anyway.

What must I change to prevent the trailing slash?

Solution

The way you have defined your Contexts is the reason for that.

A ContextHandler is a "root" to a set of resources, and that root is defined to always be a resource directory (in structure).

Since you defined ContextHandler("/api/accounts") and accessed /api/accounts the implementation "helps" you by making /api/accounts/ the correct Context root.

Imagine this ...

You have val b = ContextHandler("/a/b")
You have val a = ContextHandler("/a") - which implements (internally) support for sub-resource /b
If you request /a/b, which context are you in? - Per spec, you are in context a
If you request /a/b/, then you are in context b