Several enhancements

boot/pom.xml

@@ -33,12 +33,7 @@
     <name>Apache Karaf Minho :: Boot</name>
 
     <dependencies>
-        <dependency>
-            <groupId>org.projectlombok</groupId>
-            <artifactId>lombok</artifactId>
-            <version>${lombok.version}</version>
-            <scope>provided</scope>
-        </dependency>
+        <!-- are you sure, probably not -->
     </dependencies>
 
     <build>

boot/src/main/java/org/apache/karaf/minho/boot/Main.java

@@ -17,44 +17,57 @@
  */
 package org.apache.karaf.minho.boot;
 
-import lombok.extern.java.Log;
-
 import java.io.IOException;
+import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLClassLoader;
-import java.nio.file.*;
-import java.nio.file.attribute.BasicFileAttributes;
-import java.util.ArrayList;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.function.Predicate;
+import java.util.logging.Logger;
+
+import static java.util.Optional.ofNullable;
 
-@Log
 public class Main {
+    private Main() {
+        // no-op
+    }
 
-    public static final void main(String[] args) throws Exception {
-        boolean minhoJar = false;
-        minhoJar = (System.getenv("MINHO_JAR") != null) ? System.getenv("MINHO_JAR").equalsIgnoreCase("true") : minhoJar;
-        minhoJar = (System.getProperty("minho.jar") != null) ? System.getProperty("minho.jar").equalsIgnoreCase("true") : minhoJar;
+    public static void main(final String... args) throws Exception {
+        final boolean minhoJar = Boolean.parseBoolean(System.getenv("MINHO_JAR")) || Boolean.parseBoolean(System.getProperty("minho.jar"));
 
+        final var log = Logger.getLogger(Main.class.getName());
         if (!minhoJar) {
             log.info("Starting runtime in exploded mode");
             // try to load classpath
-            String minhoLib = (System.getProperty("minho.lib") != null) ? System.getProperty("minho.lib") : System.getProperty("user.dir");
+            final var minhoLib = ofNullable(System.getProperty("minho.lib"))
+                    .orElseGet(() -> System.getProperty("user.dir"));
             System.out.println("Minho lib: " + minhoLib);
-            Path libFolder = Paths.get(minhoLib);
-            ArrayList<URL> urls = new ArrayList<URL>();
-            Files.walkFileTree(libFolder, new SimpleFileVisitor<>() {
-                public FileVisitResult visitFile(Path file, BasicFileAttributes attributes) throws IOException {
-                    if (!Files.isDirectory(file)) {
-                        urls.add(file.toFile().toURI().toURL());
+            final var libFolder = Paths.get(minhoLib);
+            try (final var walk = Files.walk(libFolder)) {
+                final var urls = walk
+                        .filter(Predicate.not(Files::isDirectory))
+                        .map(it -> {
+                            try {
+                                return it.toUri().toURL();
+                            } catch (final MalformedURLException e) {
+                                throw new IllegalStateException(e);
+                            }
+                        })
+                        .toArray(URL[]::new);
+                final var classLoader = new URLClassLoader(urls);
+                Runtime.getRuntime().addShutdownHook(new Thread(() -> {
+                    try {
+                        classLoader.close();
+                    } catch (final IOException e) {
+                        // no-op, not critical
                     }
-                    return FileVisitResult.CONTINUE;
-                }
-            });
-            URLClassLoader classLoader = new URLClassLoader(urls.toArray(new URL[]{}));
-            Thread.currentThread().setContextClassLoader(classLoader);
+                }, Main.class.getName() + "-classloader-close"));
+                Thread.currentThread().setContextClassLoader(classLoader);
+            }
         } else {
             log.info("Starting runtime in uber jar mode");
         }
-        Minho.builder().build().start();
+        SimpleMain.main(args);
     }
-
 }

boot/src/main/java/org/apache/karaf/minho/boot/Minho.java

@@ -17,28 +17,38 @@
  */
 package org.apache.karaf.minho.boot;
 
-import lombok.Builder;
-import lombok.Data;
-import lombok.extern.java.Log;
 import org.apache.karaf.minho.boot.service.ServiceRegistry;
 import org.apache.karaf.minho.boot.spi.Service;
 import org.apache.karaf.minho.boot.spi.ServiceLoader;
+import org.apache.karaf.minho.boot.spi.impl.DefaultLoaderService;
 
-import java.util.Comparator;
-import java.util.stream.Stream;
+import java.util.Objects;
 
 /**
  * Main Karaf runtime.
  */
-@Log
-@Builder
-@Data
-public class Minho implements AutoCloseable {
-
-    private static Minho instance;
-
+public class Minho implements AutoCloseable, Service {
     private final ServiceLoader loader;
     private final ServiceRegistry serviceRegistry = new ServiceRegistry();
+    private volatile boolean closed = false;
+
+    protected Minho(final ServiceLoader loader) {
+        this.loader = loader;
+    }
+
+    public ServiceRegistry getServiceRegistry() {
+        return serviceRegistry;
+    }
+
+    @Override
+    public String name() {
+        return "minho";
+    }
+
+    @Override
+    public int priority() {
+        return Integer.MIN_VALUE;
+    }
 
     /**
      * Start the Karaf runtime.
@@ -47,40 +57,43 @@ public class Minho implements AutoCloseable {
      */
     public Minho start() {
         // log format
-        if (System.getProperty("java.util.logging.config.file") == null) {
-            if (System.getenv("KARAF_LOG_FORMAT") != null) {
-                System.setProperty("java.util.logging.SimpleFormatter.format", System.getenv("KARAF_LOG_FORMAT"));
-            }
-            if (System.getProperty("java.util.logging.SimpleFormatter.format") == null) {
-                System.setProperty("java.util.logging.SimpleFormatter.format", "%1$tF %1$tT.%1$tN %4$s [ %2$s ] : %5$s%6$s%n");
-            }
+        if (System.getProperty("java.util.logging.config.file") == null &&
+                System.getProperty("java.util.logging.SimpleFormatter.format") == null) {
+            System.setProperty("java.util.logging.SimpleFormatter.format",
+                    Objects.requireNonNullElse(System.getenv("MINHO_LOG_FORMAT"), "%1$tF %1$tT.%1$tN %4$s [ %2$s ] : %5$s%6$s%n"));
         }
-        (this.loader == null ? loadServices() : this.loader.load()).forEach(serviceRegistry::add);
+        serviceRegistry.add(this);
+        loader.load().forEach(serviceRegistry::add);
         serviceRegistry.start();
-        instance = this;
-        return instance;
-    }
-
-    private Stream<Service> loadServices() {
-        return java.util.ServiceLoader.load(Service.class).stream().map(java.util.ServiceLoader.Provider::get)
-                .sorted(Comparator.comparingInt(service -> Integer.getInteger(service.name() + ".priority", service.priority())));
+        return this;
     }
 
     /**
-     * Close (stop) the Karaf runtime.
+     * Close (stop) the Minho runtime.
      */
     @Override
     public void close() {
+        if (closed) {
+            return;
+        }
+        closed = true;
         serviceRegistry.close();
     }
 
-    /**
-     * Retrieve the Minho instance.
-     *
-     * @return the Minho instance.
-     */
-    public static Minho getInstance() {
-        return instance;
+    public static Builder builder() {
+        return new Builder();
     }
 
+    public static class Builder {
+        private ServiceLoader loader = new DefaultLoaderService();
+
+        public Builder loader(final ServiceLoader loader) {
+            this.loader = loader;
+            return this;
+        }
+
+        public Minho build() {
+            return new Minho(loader);
+        }
+    }
 }

boot/src/main/java/org/apache/karaf/minho/boot/SimpleMain.java

@@ -0,0 +1,51 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.karaf.minho.boot;
+
+import org.apache.karaf.minho.boot.service.ConfigService;
+
+import java.util.concurrent.CountDownLatch;
+
+public class SimpleMain {
+    private SimpleMain() {
+        // no-op
+    }
+
+    public static void main(final String... args) throws Exception {
+        try (final var instance = Minho.builder().build().start()) {
+            final var registry = instance.getServiceRegistry();
+            final var awaiter = registry.get(Awaiter.class);
+            if (awaiter != null) {
+                awaiter.await();
+            } else if (Boolean.getBoolean(registry.get(ConfigService.class).property("minho.awaiter.implicit", "false"))) {
+                new CountDownLatch(1).await();
+            }
+        }
+    }
+
+    /**
+     * Service implementation enabling the main to not quit immediately if set.
+     * Often used for servers.
+     */
+    public interface Awaiter {
+        /**
+         * Wait until the application completes and can exit.
+         */
+        void await();
+    }
+}

boot/src/main/java/org/apache/karaf/minho/boot/config/Application.java

@@ -17,27 +17,71 @@
  */
 package org.apache.karaf.minho.boot.config;
 
-import lombok.Data;
-
 import java.util.HashMap;
 import java.util.Map;
 
-@Data
+// todo: move to record
 public class Application {
-
     private String name;
     private String version;
     private String url;
     private String type;
     private String profile;
     private Map<String, String> properties = new HashMap<>();
 
-    public String getProperty(String key) {
-        return getProperty(key, null);
+    public String property(final String key) {
+        return property(key, null);
+    }
+
+    public String property(String key, String defaultValue) {
+        return Config.property(key, properties, defaultValue);
     }
 
-    public String getProperty(String key, String defaultValue) {
-        return Config.getProperty(key, properties, defaultValue);
+    public String getName() {
+        return name;
     }
 
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    public String getVersion() {
+        return version;
+    }
+
+    public void setVersion(final String version) {
+        this.version = version;
+    }
+
+    public String getUrl() {
+        return url;
+    }
+
+    public void setUrl(final String url) {
+        this.url = url;
+    }
+
+    public String getType() {
+        return type;
+    }
+
+    public void setType(final String type) {
+        this.type = type;
+    }
+
+    public String getProfile() {
+        return profile;
+    }
+
+    public void setProfile(final String profile) {
+        this.profile = profile;
+    }
+
+    public Map<String, String> getProperties() {
+        return properties;
+    }
+
+    public void setProperties(final Map<String, String> properties) {
+        this.properties = properties;
+    }
 }