#22 don't register Vaadin servlet manually but rely on Jetty classpat…

…h scanning. Fixes #22

README.md

@@ -317,6 +317,21 @@ public class Main {
 }
 ```
 
+This way is not recommended since any annotations on the servlet will be ignored.
+
+### Overriding Vaadin Servlet
+
+Simply introduce a class into your project which extends `VaadinServlet`, then add any necessary annotations,
+for example:
+
+```java
+@WebServlet(name = "myservlet", urlPatterns = {"/*"}, initParams = @WebInitParam(name = "foo", value = "bar"))
+class MyServlet extends VaadinServlet {}
+```
+
+By default, Vaadin's `ServletDeployer` will auto-register `VaadinServlet` but it will skip
+this kind of registration if there's already another servlet inheriting from `VaadinServlet`.
+
 ## Packaging Your Apps
 
 This part documents hints for buildscripts (`pom.xml`/`build.gradle`) of your app. When in doubt, take a look

testapp-kotlin/src/main/kotlin/com/example/Bootstrap.kt

@@ -63,14 +63,12 @@ class AppShell : AppShellConfigurator
 /**
  * Tests a custom servlet with an init parameter. Tests for https://github.com/mvysny/vaadin-boot/issues/22
  */
-@WebServlet(name = "myservlet", initParams = [WebInitParam(name = "foo", value = "bar")])
+@WebServlet(name = "myservlet", urlPatterns = ["/*"], initParams = [WebInitParam(name = "foo", value = "bar")])
 class MyServlet : VaadinServlet()
 
 object Main {
     @JvmStatic
     fun main(args: Array<String>) {
-        VaadinBoot()
-            .withServlet(MyServlet::class.java as Class<Servlet>)
-            .run()
+        VaadinBoot().run()
     }
 }

testapp-kotlin/src/test/kotlin/com/example/JettyTest.kt

@@ -19,7 +19,7 @@ class JettyTest {
     @BeforeEach
     fun startJetty() {
         assertFalse(Bootstrap.initialized)
-        vaadinBoot = VaadinBoot().setPort(44312).localhostOnly().withServlet(MyServlet::class.java as Class<Servlet>)
+        vaadinBoot = VaadinBoot().setPort(44312).localhostOnly()
         vaadinBoot!!.start()
     }
 
@@ -43,6 +43,7 @@ class JettyTest {
         require(response.statusCode() == 200) {
             "$response failed: ${response.body()}"
         }
-        println("Vaadin responded with: $response ${response.body()}")
+        val body = response.body()
+        assertTrue(body.contains("This file is auto-generated by Vaadin."), body);
     }
 }

testapp/src/test/java/com/example/JettyTest.java

@@ -46,6 +46,7 @@ public void testAppIsUp() throws Exception {
         if (response.statusCode() != 200) {
             throw new IOException(response + " failed: " + response.body());
         }
-        System.out.println("Vaadin responded with: " + response + " " + response.body());
+        final String body = response.body();
+        assertTrue(body.contains("This file is auto-generated by Vaadin."), body);
     }
 }

vaadin-boot/src/main/java/com/github/mvysny/vaadinboot/VaadinBoot.java

@@ -47,13 +47,6 @@ public class VaadinBoot {
     @VisibleForTesting
     int port = Integer.parseInt(Env.getProperty("SERVER_PORT", "server.port", "" + DEFAULT_PORT));
 
-    /**
-     * The VaadinServlet.
-     */
-    @VisibleForTesting
-    @NotNull
-    Class<? extends Servlet> servlet;
-
     /**
      * Listen on interface handling given host name. Defaults to <code>null</code> which causes Jetty
      * to listen on all interfaces.
@@ -106,17 +99,6 @@ public class VaadinBoot {
      */
     private boolean useVirtualThreadsIfAvailable = true;
 
-    /**
-     * Creates the new instance of the Boot launcher.
-     */
-    public VaadinBoot() {
-        try {
-            servlet = Class.forName("com.vaadin.flow.server.VaadinServlet").asSubclass(Servlet.class);
-        } catch (ClassNotFoundException e) {
-            throw new RuntimeException(e);
-        }
-    }
-
     /**
      * Sets the port to listen on. Listens on {@value #DEFAULT_PORT} by default.
      * @param port the new port, 1..65535
@@ -152,17 +134,6 @@ public VaadinBoot localhostOnly() {
         return listenOn("localhost");
     }
 
-    /**
-     * Bootstraps custom servlet instead of the default <code>com.vaadin.flow.server.VaadinServlet</code>.
-     * @param vaadinServlet the custom servlet, not null.
-     * @return this
-     */
-    @NotNull
-    public VaadinBoot withServlet(@NotNull Class<? extends Servlet> vaadinServlet) {
-        this.servlet = Objects.requireNonNull(vaadinServlet);
-        return this;
-    }
-
     /**
      * Change this to e.g. /foo to host your app on a different context root
      * @param contextRoot the new context root, e.g. `/foo`.
@@ -360,7 +331,11 @@ protected WebAppContext createWebAppContext() throws IOException {
         final Resource webRoot = Env.findWebRoot(context.getResourceFactory());
         context.setBaseResource(webRoot);
         context.setContextPath(contextRoot);
-        context.addServlet(servlet, "/*");
+
+        // don't add the servlet this way - the @WebServlet annotation is ignored!
+        // https://github.com/mvysny/vaadin-boot/issues/22
+//        context.addServlet(servlet, "/*");
+
         // when the webapp fails to initialize, make sure that start() throws.
         context.setThrowUnavailableOnStartupException(true);
         if (!disableClasspathScanning) {

vaadin-boot/src/test/java/com/github/mvysny/vaadinboot/VaadinBootTest.java

@@ -1,9 +1,5 @@
 package com.github.mvysny.vaadinboot;
 
-import com.vaadin.flow.server.VaadinServlet;
-import jakarta.servlet.Servlet;
-import jakarta.servlet.annotation.WebInitParam;
-import jakarta.servlet.annotation.WebServlet;
 import org.eclipse.jetty.ee10.webapp.WebAppContext;
 import org.jetbrains.annotations.NotNull;
 import org.junit.jupiter.api.BeforeEach;
@@ -127,12 +123,4 @@ public void scanTestClasspathModifiesWebAppConfig() throws Exception {
         final WebAppContext ctx = new VaadinBoot().scanTestClasspath().createWebAppContext();
         assertEquals(".*\\.jar|.*/classes/.*|.*/test-classes/.*", ctx.getAttribute("org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern"));
     }
-
-    @WebServlet(name = "myservlet", initParams = @WebInitParam(name = "foo", value = "bar"))
-    public static class MyServlet extends VaadinServlet {}
-
-    @Test
-    public void smokeCustomServlet() throws Exception {
-        new VaadinBoot().withServlet((Class<? extends Servlet>) MyServlet.class);
-    }
 }