SPI Config API for Jersey (#4116)

Config SPI API for Jersey

Signed-off-by: Maxim Nesen <maxim.nesen@oracle.com>

bom/pom.xml

@@ -148,6 +148,11 @@
                 <artifactId>jersey-metainf-services</artifactId>
                 <version>${project.version}</version>
             </dependency>
+            <dependency>
+                <groupId>org.glassfish.jersey.ext</groupId>
+                <artifactId>jersey-mp-config</artifactId>
+                <version>${project.version}</version>
+            </dependency>
             <dependency>
                 <groupId>org.glassfish.jersey.ext</groupId>
                 <artifactId>jersey-mvc</artifactId>

core-common/src/main/java/org/glassfish/jersey/CommonProperties.java

@@ -216,6 +216,17 @@ public final class CommonProperties {
      */
     public static final String OUTBOUND_CONTENT_LENGTH_BUFFER_SERVER = "jersey.config.server.contentLength.buffer";
 
+    /**
+     * Property which allows (if true) default System properties configuration provider.
+     *
+     * Effective if there are no any external properties providers
+     *
+     * Shall be set (if used) in system properties.
+     * @since 2.29
+     */
+
+    public static final String ALLOW_SYSTEM_PROPERTIES_PROVIDER = "jersey.config.allowSystemPropertiesProvider";
+
     /**
      * Prevent instantiation.
      */

core-common/src/main/java/org/glassfish/jersey/internal/config/ExternalPropertiesAutoDiscoverable.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2019 Oracle and/or its affiliates. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0, which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the
+ * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
+ * version 2 with the GNU Classpath Exception, which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ */
+
+package org.glassfish.jersey.internal.config;
+
+import org.glassfish.jersey.internal.spi.AutoDiscoverable;
+
+import javax.annotation.Priority;
+import javax.ws.rs.ConstrainedTo;
+import javax.ws.rs.RuntimeType;
+import javax.ws.rs.core.FeatureContext;
+
+@ConstrainedTo(RuntimeType.CLIENT) //server is configured directly in ResourceConfig
+@Priority(AutoDiscoverable.DEFAULT_PRIORITY)
+public class ExternalPropertiesAutoDiscoverable implements AutoDiscoverable {
+    @Override
+    public void configure(FeatureContext context) {
+        if (!context.getConfiguration().isRegistered(ExternalPropertiesConfigurationFeature.class)) {
+            context.register(ExternalPropertiesConfigurationFeature.class);
+        }
+    }
+}

core-common/src/main/java/org/glassfish/jersey/internal/config/ExternalPropertiesConfigurationFactory.java

@@ -0,0 +1,152 @@
+/*
+ * Copyright (c) 2019 Oracle and/or its affiliates. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0, which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the
+ * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
+ * version 2 with the GNU Classpath Exception, which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ */
+
+package org.glassfish.jersey.internal.config;
+
+import org.glassfish.jersey.internal.ServiceFinder;
+import org.glassfish.jersey.spi.ExternalConfigurationModel;
+import org.glassfish.jersey.spi.ExternalConfigurationProvider;
+
+import javax.annotation.Priority;
+import javax.ws.rs.Priorities;
+import javax.ws.rs.core.Configurable;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.SortedSet;
+import java.util.TreeSet;
+
+/**
+ * Factory for external properties providers
+ * Offers methods to work with properties loaded from providers or
+ * just configure Jersey's Configurables with loaded properties from providers
+ */
+public class ExternalPropertiesConfigurationFactory {
+
+    private static final List<ExternalConfigurationProvider> EXTERNAL_CONFIGURATION_PROVIDERS =
+            getExternalConfigurations();
+
+
+    /**
+     * Map of merged properties from all found providers
+     *
+     * @return map of merged properties from all found/plugged providers
+     */
+    static Map<String, Object> readExternalPropertiesMap() {
+
+        final ExternalConfigurationProvider provider = mergeConfigs(EXTERNAL_CONFIGURATION_PROVIDERS);
+        return provider == null ? Collections.emptyMap() : provider.getProperties();
+    }
+
+
+    /**
+     * Input Configurable object shall be provided in order to be filled with all found properties
+     *
+     * @param config Input Configurable initialised object to be filled with properties
+     * @return true if configured false otherwise
+     */
+
+    public static boolean configure(Configurable config) {
+
+        if (config instanceof ExternalConfigurationModel) {
+            return false; //shall not configure itself
+        }
+
+        final Map<String, Object> properties = readExternalPropertiesMap();
+
+        properties.forEach((k, v) -> config.property(k, v));
+
+        return true;
+    }
+
+    /**
+     * Merged config model from all found configuration models
+     *
+     * @return merged Model object with all properties
+     */
+    static ExternalConfigurationModel getConfig() {
+        final ExternalConfigurationProvider provider = mergeConfigs(getExternalConfigurations());
+        return provider == null ? null : provider.getConfiguration();
+    }
+
+    /**
+     * List of all found models as they are found by Jersey
+     *
+     * @return list of models (or empty list)
+     */
+    private static List<ExternalConfigurationProvider> getExternalConfigurations() {
+        final List<ExternalConfigurationProvider> providers = new ArrayList<>();
+        final ServiceFinder<ExternalConfigurationProvider> finder =
+                ServiceFinder.find(ExternalConfigurationProvider.class);
+        if (finder.iterator().hasNext()) {
+            finder.forEach(providers::add);
+        } else {
+            providers.add(new SystemPropertiesConfigurationProvider());
+        }
+        return providers;
+    }
+
+    private static ExternalConfigurationProvider mergeConfigs(List<ExternalConfigurationProvider> configurations) {
+        final Set<ExternalConfigurationProvider> orderedConfigurations = orderConfigs(configurations);
+        final Iterator<ExternalConfigurationProvider> configurationIterator = orderedConfigurations.iterator();
+        if (!configurationIterator.hasNext()) {
+            return null;
+        }
+        final ExternalConfigurationProvider firstConfig = configurationIterator.next();
+        while (configurationIterator.hasNext()) {
+            final ExternalConfigurationProvider nextConfig = configurationIterator.next();
+            firstConfig.merge(nextConfig.getConfiguration());
+        }
+
+        return firstConfig;
+    }
+
+    private static Set<ExternalConfigurationProvider> orderConfigs(List<ExternalConfigurationProvider> configurations) {
+
+        final SortedSet<ExternalConfigurationProvider> sortedSet = new TreeSet<>(new ConfigComparator());
+        sortedSet.addAll(configurations);
+        return Collections.unmodifiableSortedSet(sortedSet);
+    }
+
+    private static class ConfigComparator implements Comparator<ExternalConfigurationProvider> {
+
+        @Override
+        public int compare(ExternalConfigurationProvider config1, ExternalConfigurationProvider config2) {
+
+            boolean config1PriorityPresent = config1.getClass().isAnnotationPresent(Priority.class);
+            boolean config2PriorityPresent = config2.getClass().isAnnotationPresent(Priority.class);
+
+            int priority1 = Priorities.USER;
+            int priority2 = Priorities.USER;
+
+            if (config1PriorityPresent) {
+                priority1 = config1.getClass().getAnnotation(Priority.class).value();
+            }
+            if (config2PriorityPresent) {
+                priority2 = config2.getClass().getAnnotation(Priority.class).value();
+            }
+
+            if (priority1 == priority2) {
+                return config1.getClass().getName().compareTo(config2.getClass().getName());
+            }
+            return Integer.compare(priority1, priority2);
+        }
+    }
+}

core-common/src/main/java/org/glassfish/jersey/internal/config/ExternalPropertiesConfigurationFeature.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2019 Oracle and/or its affiliates. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0, which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the
+ * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
+ * version 2 with the GNU Classpath Exception, which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ */
+
+package org.glassfish.jersey.internal.config;
+
+import javax.ws.rs.core.Feature;
+import javax.ws.rs.core.FeatureContext;
+
+public class ExternalPropertiesConfigurationFeature implements Feature {
+
+    @Override
+    public boolean configure(FeatureContext configurableContext) {
+        return ExternalPropertiesConfigurationFactory.configure(configurableContext);
+    }
+
+}