Helidon service Shade maven plugin transformer

maven-plugins/pom.xml

@@ -42,5 +42,6 @@
         <module>sitegen-maven-plugin</module>
         <module>snakeyaml-codegen-maven-plugin</module>
         <module>stager-maven-plugin</module>
+        <module>shade-extensions</module>
     </modules>
 </project>

maven-plugins/shade-extensions/README.md

@@ -0,0 +1,35 @@
+# Helidon Shade Maven Plugin Extensions
+
+Allows shading Helidon artefacts with[ Maven Shade plugin](https://maven.apache.org/plugins/maven-shade-plugin/) 
+by providing transformer for combining `META-INF/helidon/service-registry.json` files to single one.
+
+### General usage
+
+```xml
+<plugin>
+    <groupId>org.apache.maven.plugins</groupId>
+    <artifactId>maven-shade-plugin</artifactId>
+    <version>3.5.1</version>
+    <executions>
+        <execution>
+            <phase>package</phase>
+            <goals>
+                <goal>shade</goal>
+            </goals>
+            <configuration>
+                <transformers>
+                    <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer"/>
+                    <transformer implementation="io.helidon.shade.transformers.HelidonServiceTransformer"/>
+                </transformers>
+            </configuration>
+        </execution>
+    </executions>
+    <dependencies>
+        <dependency>
+            <groupId>io.helidon.build-tools</groupId>
+            <artifactId>helidon-shade-extensions</artifactId>
+            <version>4.0.0-SNAPSHOT</version>
+        </dependency>
+    </dependencies>
+</plugin>
+```

maven-plugins/shade-extensions/pom.xml

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    Copyright (c) 2024 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.
+
+-->
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>io.helidon.build-tools</groupId>
+        <artifactId>helidon-build-tools-project</artifactId>
+        <version>4.0.0-SNAPSHOT</version>
+        <relativePath>../../pom.xml</relativePath>
+    </parent>
+    <artifactId>helidon-shade-extensions</artifactId>
+    <name>Helidon Shade Maven Plugin Extensions</name>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-shade-plugin</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.eclipse</groupId>
+            <artifactId>yasson</artifactId>
+        </dependency>
+    </dependencies>
+</project>

maven-plugins/shade-extensions/src/main/java/io/helidon/shade/transformers/HelidonServiceTransformer.java

@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2024 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.shade.transformers;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+import java.util.jar.JarEntry;
+import java.util.jar.JarOutputStream;
+
+import jakarta.json.Json;
+import jakarta.json.JsonArray;
+import jakarta.json.JsonArrayBuilder;
+import jakarta.json.JsonValue;
+import org.apache.maven.plugins.shade.relocation.Relocator;
+import org.apache.maven.plugins.shade.resource.ReproducibleResourceTransformer;
+
+/**
+ * Maven Shade plugin custom transformer for merging Helidon service-registry files.
+ * Usage:
+ * <pre>{@code
+ * <plugin>
+ *    <groupId>org.apache.maven.plugins</groupId>
+ *    <artifactId>maven-shade-plugin</artifactId>
+ *    <version>3.5.1</version>
+ *    <executions>
+ *        <execution>
+ *            <phase>package</phase>
+ *            <goals>
+ *                <goal>shade</goal>
+ *            </goals>
+ *            <configuration>
+ *                <transformers>
+ *                    <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer"/>
+ *                    <transformer implementation="io.helidon.shade.transformers.HelidonServiceTransformer"/>
+ *                </transformers>
+ *            </configuration>
+ *        </execution>
+ *    </executions>
+ *    <dependencies>
+ *        <dependency>
+ *            <groupId>io.helidon.build-tools</groupId>
+ *            <artifactId>helidon-shade-extensions</artifactId>
+ *            <version>4.0.0-SNAPSHOT</version>
+ *        </dependency>
+ *    </dependencies>
+ * </plugin>
+ * }</pre>
+ */
+public class HelidonServiceTransformer implements ReproducibleResourceTransformer {
+
+    private static final String PATH = "META-INF/helidon/service-registry.json";
+    private final JsonArrayBuilder jsonArrayBuilder = Json.createArrayBuilder();
+    private JsonArray result = null;
+
+    @Override
+    public boolean canTransformResource(String resource) {
+        return resource.equals(PATH);
+    }
+
+    @Override
+    public void processResource(String resource, InputStream is, List<Relocator> relocators) throws IOException {
+        processResource(resource, is, relocators, 0);
+    }
+
+    @Override
+    public boolean hasTransformedResource() {
+        return getResult().isEmpty();
+    }
+
+    @Override
+    public void modifyOutputStream(JarOutputStream jarOutputStream) throws IOException {
+        JarEntry jarEntry = new JarEntry(PATH);
+        jarEntry.setTime(Long.MIN_VALUE);
+        jarOutputStream.putNextEntry(jarEntry);
+        Writer writer = new OutputStreamWriter(jarOutputStream, StandardCharsets.UTF_8);
+        Json.createWriter(writer).write(getResult());
+        writer.close();
+    }
+
+    @Override
+    public void processResource(String resource, InputStream is, List<Relocator> relocators, long time) throws IOException {
+        JsonArray array = Json.createReader(is).readArray();
+        for (JsonValue value : array) {
+            jsonArrayBuilder.add(value);
+        }
+    }
+
+    private JsonArray getResult() {
+        if (result == null) {
+            result = jsonArrayBuilder.build();
+        }
+
+        return result;
+    }
+
+}

pom.xml

@@ -171,6 +171,8 @@
         <version.lib.spotbugs-annotations>3.1.12</version.lib.spotbugs-annotations>
         <version.lib.wagon-http>3.5.3</version.lib.wagon-http>
         <version.lib.commons-text>1.10.0</version.lib.commons-text>
+        <version.lib.maven-shade-plugin>3.5.1</version.lib.maven-shade-plugin>
+        <version.lib.yasson>3.0.4</version.lib.yasson>
 
         <!--
             !Version statement! - end
@@ -942,6 +944,16 @@
                 <artifactId>commons-text</artifactId>
                 <version>${version.lib.commons-text}</version>
             </dependency>
+            <dependency>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>${version.lib.maven-shade-plugin}</version>
+            </dependency>
+            <dependency>
+                <groupId>org.eclipse</groupId>
+                <artifactId>yasson</artifactId>
+                <version>${version.lib.yasson}</version>
+            </dependency>
         </dependencies>
     </dependencyManagement>