Context

You can get request's attribute from Context, the below method is NPE handled (you will get an empty string if it is null)

Query Params

You can use Context Object to extract query params

// Get query params, ex: /query?hello=world
server.get("/query", ctx -> {
    val world = ctx.queryParam("hello");
    return HttpResponse.of("Hello: " + world);
});

Path Params

You can use Context Object to extract path params

// Get handler params, ex: /params/:categoryID/:itemID
server.get("/params/:categoryID/:itemID", ctx -> {
    val categoryID = ctx.pathParam("categoryID");
    val itemID = ctx.pathParam("itemID");
    return HttpResponse.of("Category ID is " + categoryID + ", Item ID is " + itemID);
});

Header Params

You can use Context Object to extract header params (all attributed parsed with lowercase)

// Get handler params, ex: /params/:categoryID/:itemID
server.get("/header", ctx -> {
    val authorization = ctx.headerParam("authorization");
    val userAgent = ctx.headerParam("user-agent");
    return HttpResponse.of("Authorization is " + authorization + ", UserAgent is " + userAgent);
});