Support GSON media

bom/pom.xml

@@ -296,6 +296,11 @@
                 <artifactId>jersey-media-json-processing</artifactId>
                 <version>${project.version}</version>
             </dependency>
+            <dependency>
+                <groupId>org.glassfish.jersey.media</groupId>
+                <artifactId>jersey-media-json-gson</artifactId>
+                <version>${project.version}</version>
+            </dependency>
             <dependency>
                 <groupId>org.glassfish.jersey.media</groupId>
                 <artifactId>jersey-media-json-binding</artifactId>

media/json-gson/pom.xml

@@ -0,0 +1,81 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    Copyright (c) 2022 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
+
+-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.glassfish.jersey.media</groupId>
+        <artifactId>project</artifactId>
+        <version>2.37-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>jersey-media-json-gson</artifactId>
+    <packaging>jar</packaging>
+    <name>jersey-media-json-gson</name>
+
+    <description>
+        Jersey GSON support module.
+    </description>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>com.sun.istack</groupId>
+                <artifactId>istack-commons-maven-plugin</artifactId>
+                <inherited>true</inherited>
+            </plugin>
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>build-helper-maven-plugin</artifactId>
+                <inherited>true</inherited>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.felix</groupId>
+                <artifactId>maven-bundle-plugin</artifactId>
+                <inherited>true</inherited>
+                <extensions>true</extensions>
+                <configuration>
+                    <instructions>
+                        <Export-Package>org.glassfish.jersey.gson.*</Export-Package>
+                        <Import-Package>${javax.annotation.osgi.version},*</Import-Package>
+                    </instructions>
+                    <unpackBundle>true</unpackBundle>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.glassfish.jersey.core</groupId>
+            <artifactId>jersey-common</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.google.code.gson</groupId>
+            <artifactId>gson</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>

media/json-gson/src/main/java/org/glassfish/jersey/gson/JsonGsonFeature.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2022 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.gson;
+
+import javax.ws.rs.core.Configuration;
+import javax.ws.rs.core.Feature;
+import javax.ws.rs.core.FeatureContext;
+
+import org.glassfish.jersey.CommonProperties;
+import org.glassfish.jersey.gson.internal.JsonGsonAutoDiscoverable;
+import org.glassfish.jersey.gson.internal.JsonGsonProvider;
+import org.glassfish.jersey.internal.InternalProperties;
+import org.glassfish.jersey.internal.util.PropertiesHelper;
+/**
+ * Feature used to register Gson providers.
+ * <p>
+ * The Feature is automatically enabled when {@link JsonGsonAutoDiscoverable} is on classpath.
+ * Default GSON configuration obtained by calling {@code GsonBuilder.create()} is used.
+ * <p>
+ * Custom configuration, if required, can be achieved by implementing custom {@link javax.ws.rs.ext.ContextResolver} and
+ * registering it as a provider into JAX-RS runtime:
+ * <pre>
+ * &#64;Provider
+ * &#64;class GsonContextResolver implements ContextResolver&lt;Gson&gt; {
+ *      &#64;Override
+ *      public Gson getContext(Class<?> type) {
+ *          GsonBuilder builder = new GsonBuilder();
+ *          // add custom configuration
+ *          return builder.create();
+ *      }
+ * }
+ * </pre>
+ *
+ */
+public class JsonGsonFeature implements Feature {
+
+    private static final String JSON_FEATURE = JsonGsonFeature.class.getSimpleName();
+
+    @Override
+    public boolean configure(final FeatureContext context) {
+        final Configuration config = context.getConfiguration();
+
+        final String jsonFeature = CommonProperties.getValue(
+                config.getProperties(),
+                config.getRuntimeType(),
+                InternalProperties.JSON_FEATURE, JSON_FEATURE, String.class);
+
+        // Other JSON providers registered.
+        if (!JSON_FEATURE.equalsIgnoreCase(jsonFeature)) {
+            return false;
+        }
+
+        // Disable other JSON providers.
+        context.property(PropertiesHelper.getPropertyNameForRuntime(
+                InternalProperties.JSON_FEATURE, config.getRuntimeType()), JSON_FEATURE);
+
+        context.register(JsonGsonProvider.class);
+
+        return true;
+    }
+}

media/json-gson/src/main/java/org/glassfish/jersey/gson/internal/JsonGsonAutoDiscoverable.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2022 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.gson.internal;
+
+import javax.annotation.Priority;
+import javax.ws.rs.core.FeatureContext;
+
+import org.glassfish.jersey.gson.JsonGsonFeature;
+import org.glassfish.jersey.internal.spi.AutoDiscoverable;
+import org.glassfish.jersey.internal.spi.ForcedAutoDiscoverable;
+
+/**
+ * {@link ForcedAutoDiscoverable} registering {@link JsonGsonFeature} if the feature is not already registered.
+ * <p>
+ *
+ * @see JsonGsonFeature
+ */
+@Priority(AutoDiscoverable.DEFAULT_PRIORITY)
+public class JsonGsonAutoDiscoverable implements ForcedAutoDiscoverable {
+
+    @Override
+    public void configure(FeatureContext context) {
+        if (!context.getConfiguration().isRegistered(JsonGsonFeature.class)) {
+            context.register(JsonGsonFeature.class);
+        }
+    }
+}

media/json-gson/src/main/java/org/glassfish/jersey/gson/internal/JsonGsonProvider.java

@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2022 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.gson.internal;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Type;
+
+import javax.ws.rs.Consumes;
+import javax.ws.rs.ProcessingException;
+import javax.ws.rs.Produces;
+import javax.ws.rs.WebApplicationException;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.MultivaluedMap;
+import javax.ws.rs.core.NoContentException;
+import javax.ws.rs.ext.ContextResolver;
+import javax.ws.rs.ext.Provider;
+import javax.ws.rs.ext.Providers;
+
+import org.glassfish.jersey.gson.LocalizationMessages;
+import org.glassfish.jersey.message.internal.AbstractMessageReaderWriterProvider;
+import org.glassfish.jersey.message.internal.EntityInputStream;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+
+/**
+ * Entity provider (reader and writer) for Gson.
+ *
+ */
+@Provider
+@Produces({"application/json", "text/json", "*/*"})
+@Consumes({"application/json", "text/json", "*/*"})
+public class JsonGsonProvider extends AbstractMessageReaderWriterProvider<Object> {
+
+    private static final String JSON = "json";
+    private static final String PLUS_JSON = "+json";
+
+    private Providers providers;
+
+    public JsonGsonProvider(@Context Providers providers) {
+        this.providers = providers;
+    }
+
+    @Override
+    public boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
+        return supportsMediaType(mediaType);
+    }
+
+    @Override
+    public Object readFrom(Class<Object> type, Type genericType,
+                           Annotation[] annotations,
+                           MediaType mediaType,
+                           MultivaluedMap<String, String> httpHeaders,
+                           InputStream entityStream) throws IOException, WebApplicationException {
+        EntityInputStream entityInputStream =  new EntityInputStream(entityStream);
+        entityStream = entityInputStream;
+        if (entityInputStream.isEmpty()) {
+            throw new NoContentException(LocalizationMessages.ERROR_GSON_EMPTYSTREAM());
+        }
+        Gson gson = getGson(type);
+        try {
+            return gson.fromJson(new InputStreamReader(entityInputStream,
+                    AbstractMessageReaderWriterProvider.getCharset(mediaType)), genericType);
+        } catch (Exception e) {
+            throw new ProcessingException(LocalizationMessages.ERROR_GSON_DESERIALIZATION(), e);
+        }
+    }
+
+    @Override
+    public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
+        return supportsMediaType(mediaType);
+    }
+
+    @Override
+    public void writeTo(Object o, Class<?> type, Type genericType,
+                        Annotation[] annotations,
+                        MediaType mediaType,
+                        MultivaluedMap<String, Object> httpHeaders,
+                        OutputStream entityStream) throws IOException, WebApplicationException {
+        Gson gson = getGson(type);
+        try {
+            entityStream.write(gson.toJson(o).getBytes(AbstractMessageReaderWriterProvider.getCharset(mediaType)));
+            entityStream.flush();
+        } catch (Exception e) {
+            throw new ProcessingException(LocalizationMessages.ERROR_GSON_SERIALIZATION(), e);
+        }
+    }
+
+    private Gson getGson(Class<?> type) {
+        final ContextResolver<Gson> contextResolver = providers.getContextResolver(Gson.class, MediaType.APPLICATION_JSON_TYPE);
+        if (contextResolver != null) {
+            return contextResolver.getContext(type);
+        } else {
+            return GsonSingleton.INSTANCE.getInstance();
+        }
+    }
+
+    /**
+     * @return true for all media types of the pattern *&#47;json and
+     * *&#47;*+json.
+     */
+    private static boolean supportsMediaType(final MediaType mediaType) {
+        return mediaType.getSubtype().equals(JSON) || mediaType.getSubtype().endsWith(PLUS_JSON);
+    }
+
+    private enum GsonSingleton {
+        INSTANCE;
+
+        // Thread-safe
+        private Gson gsonInstance;
+
+        Gson getInstance() {
+            return gsonInstance;
+        }
+
+        GsonSingleton() {
+            this.gsonInstance = new GsonBuilder().create();
+        }
+    }
+}

media/json-gson/src/main/java/org/glassfish/jersey/gson/package-info.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2022 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
+ */
+
+/**
+ * Jersey classes supporting JSON marshalling and unmarshalling using GSON.
+ */
+package org.glassfish.jersey.gson;

media/json-gson/src/main/resources/META-INF/services/org.glassfish.jersey.internal.spi.ForcedAutoDiscoverable

@@ -0,0 +1 @@
+org.glassfish.jersey.gson.internal.JsonGsonAutoDiscoverable

media/json-gson/src/main/resources/org/glassfish/jersey/gson/localization.properties

@@ -0,0 +1,19 @@
+#
+# Copyright (c) 2022 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
+#
+
+error.gson.serialization=Error writing GSON serialized object.
+error.gson.deserialization=Error deserializing object from entity stream.
+error.gson.emptystream=GSON cannot parse empty input stream.