How can I add contextRoot in Helidon SE?

[mrguamos]

as the title says, how can I add contextRoot in Helidon SE?

[romain-grecourt]

Use a path when you register handlers and services.

If you have a simple layout with just handlers, simply add a prefix to your paths:

routing.get("/acme/foo", (req, res) -> res.send("Foo"))
        .get("/acme/bar", (req, res) -> res.send("Bar"));

// /acme/foo -> "Foo"
// /acme/bar -> "Bar"

You can use services to group handlers under a common path:

routing.register("/acme", rules ->
        rules.get("/foo", (req, res) -> res.send("Foo"))
                .get("/bar", (req, res) -> res.send("Bar")));

// /acme/foo -> "Foo"
// /acme/bar -> "Bar"

Services can register nested services:

routing.register("/acme", rules1 ->
        rules1.register("/api", rules2 ->
                rules2.get("/foo", (req, res) -> res.send("Foo"))
                        .get("/bar", (req, res) -> res.send("Bar"))));

// /acme/api/foo -> "Foo"
// /acme/api/bar -> "Bar"

Note that I wrote the services using lambdas because that's more compact for answer, but in practice it's better to use a class that implements Service (3.x) or HttpService (4.x)

See the documentation here: https://helidon.io/docs/v3/#/se/webserver#_routing