Helidon Main class

- injection implementation
- CDI implementation
- refactored MP apps to use it
- refactored Níma FT example to use it

applications/mp/pom.xml

@@ -36,7 +36,7 @@
         <version.plugin.jaxb2>0.14.0</version.plugin.jaxb2>
         <version.plugin.eclipselink>2.7.5.1</version.plugin.eclipselink>
         <version.plugin.hibernate.enhance>6.1.7.Final</version.plugin.hibernate.enhance>
-        <mainClass>io.helidon.microprofile.cdi.Main</mainClass>
+        <mainClass>io.helidon.Main</mainClass>
     </properties>
 
     <build>

bom/pom.xml

@@ -37,6 +37,11 @@
 
     <dependencyManagement>
         <dependencies>
+            <dependency>
+                <groupId>io.helidon</groupId>
+                <artifactId>helidon</artifactId>
+                <version>${helidon.version}</version>
+            </dependency>
             <!-- webserver -->
             <dependency>
                 <groupId>io.helidon.reactive.webserver</groupId>
@@ -1175,16 +1180,6 @@
             </dependency>
 
             <!-- Níma -->
-            <dependency>
-                <groupId>io.helidon.nima</groupId>
-                <artifactId>helidon-nima</artifactId>
-                <version>${helidon.version}</version>
-            </dependency>
-            <dependency>
-                <groupId>io.helidon.nima.common</groupId>
-                <artifactId>helidon-nima-common-api</artifactId>
-                <version>${helidon.version}</version>
-            </dependency>
             <dependency>
                 <groupId>io.helidon.nima.common</groupId>
                 <artifactId>helidon-nima-common-tls</artifactId>

examples/nima/fault-tolerance/pom.xml

@@ -30,13 +30,13 @@
     <name>Helidon Examples Níma Fault Tolerance</name>
 
     <properties>
-        <mainClass>io.helidon.examples.nima.faulttolerance.FtMain</mainClass>
+        <mainClass>io.helidon.Main</mainClass>
     </properties>
 
     <dependencies>
         <dependency>
-            <groupId>io.helidon.nima</groupId>
-            <artifactId>helidon-nima</artifactId>
+            <groupId>io.helidon</groupId>
+            <artifactId>helidon</artifactId>
         </dependency>
         <dependency>
             <groupId>io.helidon.nima.webserver</groupId>

examples/nima/fault-tolerance/src/main/java/io/helidon/examples/nima/faulttolerance/GreetEndpoint.java

@@ -55,7 +55,6 @@ String greet() {
     String greetNamed(@Endpoint.PathParam("name") String name,
                       @Endpoint.QueryParam(value = "throw", defaultValue = "false") String shouldThrow,
                       @Endpoint.HeaderParam(Http.Header.HOST_STRING) String hostHeader) {
-        System.out.println(Thread.currentThread().getName());
         if ("true".equalsIgnoreCase(shouldThrow)) {
             throw new PicoException("Failed on purpose");
         }

examples/nima/fault-tolerance/src/main/resources/application.yaml

@@ -26,4 +26,6 @@ fault-tolerance:
     myname:
       executor-name: "platform-executor"
     other-name:
-      executor-name: "abcd"
+      executor-name: "abcd"
+pico:
+  permits-dynamic: true

examples/nima/fault-tolerance/src/test/java/io/helidon/examples/nima/faulttolerance/FaultToleranceTest.java

@@ -16,6 +16,7 @@
 
 package io.helidon.examples.nima.faulttolerance;
 
+import io.helidon.Main;
 import io.helidon.common.http.Http;
 import io.helidon.nima.webclient.WebClient;
 import io.helidon.nima.webclient.http1.Http1Client;
@@ -39,7 +40,7 @@ class FaultToleranceTest {
 
     @BeforeAll
     static void init() {
-        FtMain.main(new String[0]);
+        Main.main(new String[0]);
         WebServer webServer = PicoServices.realizedServices()
                 .lookup(WebServer.class)
                 .get();
@@ -59,8 +60,8 @@ static void init() {
 
     @AfterAll
     static void shutDown() {
-        //        PicoServices.picoServices()
-        //                .map(PicoServices::shutdown);
+        PicoServices.picoServices()
+                .map(PicoServices::shutdown);
     }
 
     @Test
@@ -95,7 +96,6 @@ void testGreetNamed() {
     }
 
     @Test
-    @Disabled
     void testGreetNamedFallback() {
         String response = webClient.get("/greet/helidon")
                 .queryParam("throw", "true")

helidon/pom.xml

@@ -35,5 +35,9 @@
             <groupId>io.helidon.common</groupId>
             <artifactId>helidon-common</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.helidon.logging</groupId>
+            <artifactId>helidon-logging-common</artifactId>
+        </dependency>
     </dependencies>
 </project>

helidon/src/main/java/io/helidon/Main.java

@@ -1,15 +1,62 @@
+/*
+ * Copyright (c) 2023 Oracle and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package io.helidon;
 
+import java.util.ServiceLoader;
+
+import io.helidon.common.HelidonServiceLoader;
+import io.helidon.logging.common.LogConfig;
+import io.helidon.spi.HelidonStartupProvider;
+
 /**
- * Main entry point for any Helidon application that is discovering services.
+ * Main entry point for any Helidon application.
+ * {@link java.util.ServiceLoader} is used to discover the correct {@link io.helidon.spi.HelidonStartupProvider}
+ * to start the application (probably either Helidon Injection based application, or a CDI based application).
+ * <p>
+ * The default option is to start Helidon injection based application.
  */
 public class Main {
+    static {
+        LogConfig.initClass();
+    }
+
+    private Main() {
+    }
+
     /**
      * Start Helidon.
+     * This method is required to start directly from a command line.
      *
      * @param args arguments of the application
      */
     public static void main(String[] args) {
+        // we always initialize logging
+        LogConfig.configureRuntime();
+
+        // this should only be called once in a lifetime of the server, so no need to optimize
+        var services = HelidonServiceLoader.create(ServiceLoader.load(HelidonStartupProvider.class))
+                .asList();
 
+        if (services.isEmpty()) {
+            throw new IllegalStateException("Helidon Main class can only be called if an startup provider is available. "
+                                                    + "Please use either Helidon Injection, or Helidon MicroProfile "
+                                                    + "(or a custom extension). If neither is available, you should use "
+                                                    + "your own Main class.");
+        }
+        services.get(0).start(args);
     }
 }

nima/common/api/src/main/java/io/helidon/nima/common/api/package-info.java → helidon/src/main/java/io/helidon/package-info.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023 Oracle and/or its affiliates.
+ * Copyright (c) 2022, 2023 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,6 +15,8 @@
  */
 
 /**
- * APIs shared across all Helidon features that are injection based.
+ * Startup of Helidon applications.
+ *
+ * @see io.helidon.Main
  */
-package io.helidon.nima.common.api;
+package io.helidon;

helidon/src/main/java/io/helidon/spi/HelidonStartupProvider.java

@@ -1,9 +1,24 @@
+/*
+ * Copyright (c) 2023 Oracle and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package io.helidon.spi;
 
 /**
  * {@link java.util.ServiceLoader} provider interface to discover the correct startup type.
  * Only the first provider (with the highest {@link io.helidon.common.Weight}) will be used.
- * The default startup will create Helidon Injection service registry, and start all services that should be started.
  */
 public interface HelidonStartupProvider {
     /**

nima/common/api/src/main/java/module-info.java → helidon/src/main/java/io/helidon/spi/package-info.java

@@ -15,10 +15,7 @@
  */
 
 /**
- * APIs for Helidon features.
+ * Extension point to support a single main class ({@link io.helidon.Main}) to start various styles of applications,
+ * such as Helidon injection based applications, and Helidon MicroProfile applications.
  */
-module io.helidon.nima.common.api {
-    requires static io.helidon.pico.api;
-
-    exports io.helidon.nima.common.api;
-}
+package io.helidon.spi;

nima/nima/src/main/java/io/helidon/nima/package-info.java → helidon/src/main/java/module-info.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2023 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,7 +15,14 @@
  */
 
 /**
- * Main entry point for Níma application.
- * Bootstraps required services, which implicitly starts server(s) available.
+ * Types need to start a Helidon application.
  */
-package io.helidon.nima;
+module io.helidon {
+    requires io.helidon.common;
+    requires io.helidon.logging.common;
+
+    exports io.helidon;
+    exports io.helidon.spi;
+
+    uses io.helidon.spi.HelidonStartupProvider;
+}

integrations/micrometer/micrometer/src/main/java/io/helidon/integrations/micrometer/MeterRegistryFactory.java

@@ -30,7 +30,6 @@
 
 import io.helidon.common.config.Config;
 import io.helidon.common.http.Http;
-import io.helidon.config.Config;
 import io.helidon.nima.webserver.http.Handler;
 import io.helidon.nima.webserver.http.ServerRequest;
 import io.helidon.nima.webserver.http.ServerResponse;

microprofile/cdi/pom.xml

@@ -32,6 +32,10 @@
     <description>Helidon extension of Weld to support ahead of time compilation</description>
 
     <dependencies>
+        <dependency>
+            <groupId>io.helidon</groupId>
+            <artifactId>helidon</artifactId>
+        </dependency>
         <dependency>
             <!-- the actual CDI implementation - repackaged by us -->
             <groupId>io.helidon.microprofile.weld</groupId>

microprofile/cdi/src/main/java/io/helidon/microprofile/cdi/CdiStartupProvider.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2023 Oracle and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.helidon.microprofile.cdi;
+
+import io.helidon.common.Weight;
+import io.helidon.common.Weighted;
+import io.helidon.spi.HelidonStartupProvider;
+
+/**
+ * {@link java.util.ServiceLoader} implementation of a Helidon startup provider.
+ */
+@Weight(Weighted.DEFAULT_WEIGHT + 100) // must have higher than default, to start CDI and not Helidon Injection
+public class CdiStartupProvider implements HelidonStartupProvider {
+    /**
+     * Default constructor required by {@link java.util.ServiceLoader}.
+     *
+     * @deprecated please do not use directly
+     */
+    @Deprecated
+    public CdiStartupProvider() {
+    }
+
+    @Override
+    public void start(String[] arguments) {
+        Main.main(arguments);
+    }
+}

microprofile/cdi/src/main/java/module-info.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2019, 2023 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -37,6 +37,7 @@
     // weld requires jakarta.el.ELResolver on module path
     requires jakarta.el;
 
+    requires io.helidon;
     requires io.helidon.common;
     requires io.helidon.logging.common;
     requires io.helidon.common.features.api;
@@ -56,6 +57,7 @@
 
     uses jakarta.enterprise.inject.spi.Extension;
 
+    provides io.helidon.spi.HelidonStartupProvider with io.helidon.microprofile.cdi.CdiStartupProvider;
     provides jakarta.enterprise.inject.se.SeContainerInitializer with io.helidon.microprofile.cdi.HelidonContainerInitializer;
     provides jakarta.enterprise.inject.spi.CDIProvider with io.helidon.microprofile.cdi.HelidonCdiProvider;