Java RouteKit

Super-fast and lightweight Java URL router.

Features

• Fast: highly efficient routing algorithm using hashtable index, prefix trie and finite state machine. No regexp matching.
• GC friendly: minimal number of allocations during routing. No unnecessary copying and String and char[] waste.
• Small: whole library is one 30kb jar.
• Scalable: can handle thousands of rules without overhead.
• Simple: supports string variables and wildcards.
• Lightweight. No dependencies on other libraries. None. Zero.
• Adaptable: API does not require or force any web framework or library. Works with any String or char[] input.
• Compatible: Netty.
• Extensible: supports options and extension points for new rule syntax, tokens or customized matching.

Example usage

// The setup: map the urls to a handler (can be any class).
Router<T> router = new RouterSetup<T>()
    .add("/", ...)
    .add("/foo", ...)
    .add("/bar", ...)
    .build();

For example, if you have a Handler hierarchy, implemented by per-page classes (HomeHandler, UserHandler, etc), it might look like this:

Router<Handler> router = new RouterSetup<Handler>()
    .add("/", new HomeHandler())
    .add("/user", new ListUsersHandler())
    .add("/user/{id}", new UserHandler())
    .add("/post", new ListBlogPostsHandler())
    .add("/post/{id}", new BlogPostHandler())
    .add("/post/{id}/{slug}", new BlogPostHandler())
        ...
    .build();

URL navigation is as follows:

Match<Handler> match = router.routeOrNull(url);
if (match == null)
    throw new NotFoundException();
return match.handler().accept(match.variables());

Note the handler can use the variables map, like id -> 123.

Performance

Benchmark results for a small/medium size setup show that routing static URL (without variables) throughput can reach 55m ops/sec, one variable URL - 10m ops/sec, two variables URL - 6m ops/sec.
Environment: AMD Ryzen 5 4600H, 3.00 GHz, single-threaded.

JMH benchmark output below:

Benchmark                                 (iterations)   Mode   Samples        Score  Score error    Units
i.r.j.RouterBenchmark.route_home                  1000  thrpt        10    55373,952     1356,069    ops/s
i.r.j.RouterBenchmark.route_post                  1000  thrpt        10    10935,147      190,314    ops/s
i.r.j.RouterBenchmark.route_post_slug             1000  thrpt        10     6207,792       59,925    ops/s
i.r.j.RouterBenchmark.route_user                  1000  thrpt        10     9918,927      290,196    ops/s