racket/collects/web-server/scribblings/servlet-env.scrbl
Jay McCarthy fe078ee54b stuffers
svn: r13474
2009-02-06 23:23:21 +00:00

215 lines
10 KiB
Racket

#lang scribble/doc
@(require "web-server.ss")
@title[#:tag "servlet-env.ss"
#:style 'toc]{Simple Single Servlet Servers}
@(require (for-label web-server/servlet-env
web-server/http
web-server/managers/lru
web-server/private/util
web-server/dispatchers/dispatch
web-server/configuration/configuration-table
web-server/configuration/responders
web-server/dispatchers/dispatch-log
scheme/serialize
web-server/stuffers
scheme/list))
@defmodule[web-server/servlet-env]{
The @web-server provides a way to quickly configure and start a server instance.
Here's a simple example:
@schememod[
scheme
(require web-server/servlet
web-server/servlet-env)
(define (my-app request)
`(html (head (title "Hello world!"))
(body (p "Hey out there!"))))
(serve/servlet my-app)
]
Suppose you'd like to change the port to something else, change the last line to:
@schemeblock[
(serve/servlet my-app
#:port 8080)
]
By default the URL for your servlet is @filepath{http://localhost:8000/servlets/standalone.ss},
suppose you wanted it to be @filepath{http://localhost:8000/hello.ss}:
@schemeblock[
(serve/servlet my-app
#:servlet-path "/hello.ss")
]
Suppose you wanted it to capture top-level requests:
@schemeblock[
(serve/servlet my-app
#:servlet-path "/")
]
Or, perhaps just some nice top-level name:
@schemeblock[
(serve/servlet my-app
#:servlet-path "/main")
]
Suppose you wanted to use a style-sheet (@filepath{style.css}) found on your Desktop (@filepath{/Users/jay/Desktop/}):
@schemeblock[
(serve/servlet my-app
#:extra-files-paths
(list
(build-path "/Users/jay/Desktop")))
]
These files are served @emph{in addition} to those from the @scheme[#:server-root-path] @filepath{htdocs} directory.
Notice that you may pass any number of extra paths.
Suppose you would like to start a server for a stateless Web servlet @filepath{servlet.ss} that provides @schemeid[start]:
@schememod[
scheme
(require "servlet.ss"
web-server/servlet-env)
(serve/servlet start #:stateless? #t)
]
Note: If you put the call to @scheme[serve/servlet] in the module like normal, strange things will happen because of the way
the top-level interacts with continuations. (Read: Don't do it.)
If you want to use @scheme[serve/servlet] in a start up script for a Web server, and don't want a browser opened or the DrScheme banner printed, then you can write:
@schemeblock[
(serve/servlet my-app
#:command-line? #t)
]
@defproc[(serve/servlet [start (request? . -> . response/c)]
[#:command-line? command-line? boolean? #f]
[#:launch-browser? launch-browser? boolean? (not command-line?)]
[#:quit? quit? boolean? (not command-line?)]
[#:banner? banner? boolean? (not command-line?)]
[#:listen-ip listen-ip (or/c false/c string?) "127.0.0.1"]
[#:port port number? 8000]
[#:ssl? ssl? boolean? #f]
[#:servlet-path servlet-path string?
"/servlets/standalone.ss"]
[#:servlet-regexp servlet-regexp regexp?
(regexp
(format
"^~a$"
(regexp-quote servlet-path)))]
[#:stateless? stateless? boolean? #f]
[#:stuffer stuffer (stuffer/c serializable? bytes?) default-stuffer]
[#:manager manager manager? (make-threshold-LRU-manager #f (* 1024 1024 64))]
[#:servlet-namespace servlet-namespace (listof module-path?) empty]
[#:server-root-path server-root-path path-string? default-server-root-path]
[#:extra-files-paths extra-files-paths (listof path-string?) (list (build-path server-root-path "htdocs"))]
[#:servlets-root servlets-root path-string? (build-path server-root-path "htdocs")]
[#:servlet-current-directory servlet-current-directory path-string? servlets-root]
[#:file-not-found-responder file-not-found-responder
(request? . -> . response/c)
(gen-file-not-found-responder
(build-path
server-root-path
"conf"
"not-found.html"))]
[#:mime-types-path mime-types-path path-string?
....]
[#:log-file log-file (or/c false/c path-string?) #f]
[#:log-format log-format log-format/c 'apache-default])
void]{
This sets up and starts a fairly default server instance.
@scheme[start] is loaded as a servlet and responds to requests that match @scheme[servlet-regexp]. The current directory
of servlet execution is @scheme[servlet-current-directory].
If @scheme[launch-browser?] is true, then a web browser is opened to @filepath{http://localhost:<port><servlet-path>}.
If @scheme[quit?] is true, then the URL @filepath["/quit"] ends the server.
If @scheme[stateless?] is true, then the servlet is run as a stateless @schememod[web-server] module and @scheme[stuffer] is used
as the @tech{stuffer}.
Advanced users may need the following options:
The server listens on @scheme[listen-ip] and port @scheme[port].
If @scheme[ssl?] is true, then the server runs in HTTPS mode with @filepath{<server-root-path>/server-cert.pem}
and @filepath{<server-root-path>/private-key.pem} as the certificates and private keys.
The servlet is loaded with @scheme[manager]
as its continuation manager. (The default manager limits the amount of memory to 64 MB and
deals with memory pressure as discussed in the @scheme[make-threshold-LRU-manager] documentation.)
The modules specified by @scheme[servlet-namespace] are shared with other servlets.
The server files are rooted at @scheme[server-root-path] (which is defaultly the distribution root.)
File paths, in addition to the @filepath["htdocs"] directory under @scheme[server-root-path] may be
provided with @scheme[extra-files-paths]. These paths are checked first, in the order they appear in the list.
Other servlets are served from @scheme[servlets-root].
If a file cannot be found, @scheme[file-not-found-responder] is used to generate an error response.
If @scheme[banner?] is true, then an informative banner is printed. You may want to use this when
running from the command line, in which case the @scheme[command-line?] option controls similar options.
MIME types are looked up at @scheme[mime-types-path]. By default the @filepath{mime.types} file in the
@scheme[server-root-path] is used, but if that file does not exist, then the file that ships with the
Web Server is used instead. Of course, if a path is given, then it overrides this behavior.
If @scheme[log-file] is given, then it used to log requests using @scheme[log-format] as the format. Allowable formats
are those allowed by @scheme[log-format->format].
}
@defproc[(dispatch/servlet
[start (request? . -> . response/c)]
[#:regexp regexp regexp? #rx""]
[#:stateless? stateless? boolean? #f]
[#:stuffer stuffer (stuffer/c serializable? bytes?) default-stuffer]
[#:manager manager manager? (make-threshold-LRU-manager #f (* 1024 1024 64))]
[#:namespace namespace (listof module-path?) empty]
[#:current-directory servlet-current-directory path-string? (current-directory)])
dispatcher/c]{
@scheme[serve/servlet] starts a server and uses a particular dispatching sequence. For some applications, this
nails down too much, but users are conflicted, because the interface is so convenient. For those users, @scheme[dispatch/servlet]
does the hardest part of @scheme[serve/servlet] and constructs a dispatcher just for the @scheme[start] servlet.
The dispatcher responds to requests that match @scheme[regexp]. The current directory
of servlet execution is @scheme[servlet-current-directory].
If @scheme[stateless?] is true, then the servlet is run as a stateless @schememod[web-server] module and @scheme[stuffer] is used
as the @tech{stuffer}.
The servlet is loaded with @scheme[manager] as its continuation manager. (The default manager limits the amount of memory to 64 MB and
deals with memory pressure as discussed in the @scheme[make-threshold-LRU-manager] documentation.)
The modules specified by @scheme[servlet-namespace] are shared with other servlets.
}
@defproc[(serve/launch/wait
[make-dispatcher (semaphore? . -> . dispatcher/c)]
[#:launch-path launch-path (or/c false/c string?) #f]
[#:banner? banner? boolean? #f]
[#:listen-ip listen-ip (or/c false/c string?) "127.0.0.1"]
[#:port port number? 8000]
[#:ssl-keys ssl-keys (or/c false/c (cons/c path-string? path-string?)) #f])
void]{
The other interesting part of @scheme[serve/servlet] is its ability to start up a server and immediately
launch a browser at it. This is provided by @scheme[serve/launch/wait].
It starts a server using the result of @scheme[make-dispatcher] as the dispatcher. @scheme[make-dispatcher] is supplied
a semaphore that if posted, will cause the server to quit.
If @scheme[launch-path] is not false, then a browser is launched with that path appended to the URL to the server itself.
If @scheme[banner?] is true, then a banner is printed informing the user of the server's URL.
The server listens on @scheme[listen-ip] and port @scheme[port].
If @scheme[ssl-keys] is not false, then the server runs in HTTPS mode with @scheme[(car ssl-keys)]
and @scheme[(cdr ssl-keys)] as paths to the certificate and private key.
}
}