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ujibangujibang
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Add GraalVM native image resource extraction
1 parent 7998558 commit bf31068

4 files changed

Lines changed: 184 additions & 2 deletions

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‎commons/src/main/java/org/restheart/utils/ResourcesExtractor.java‎

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@@ -32,10 +32,13 @@
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import java.nio.file.SimpleFileVisitor;
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import java.nio.file.StandardCopyOption;
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import java.nio.file.attribute.BasicFileAttributes;
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import java.util.ArrayList;
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import java.util.HashMap;
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import java.util.List;
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import java.util.Map;
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import java.util.regex.Pattern;
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import org.restheart.graal.ImageInfo;
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import org.slf4j.Logger;
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import org.slf4j.LoggerFactory;
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@@ -56,6 +59,32 @@ public class ResourcesExtractor {
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/** Logger instance for this class. */
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private static final Logger LOG = LoggerFactory.getLogger(ResourcesExtractor.class);
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/**
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* Map of directory paths to lists of file names, populated at build time
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* by the GraalVM Feature. Used to enumerate resources in native images
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* where ClassLoader.getResources() does not work for directories.
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*/
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private static final Map<String, List<String>> NATIVE_IMAGE_RESOURCES = new HashMap<>();
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/**
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* Registers a resource file under a directory path. Called at build time
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* by the GraalVM Feature to populate the resource map.
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*
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* @param directoryPath the directory path (e.g., "static/metrics")
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* @param fileName the file name (e.g., "restheart-metrics.html")
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*/
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public static void registerNativeImageResource(String directoryPath, String fileName) {
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NATIVE_IMAGE_RESOURCES.computeIfAbsent(directoryPath, k -> new ArrayList<>()).add(fileName);
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}
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/**
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* Returns the map of directory paths to file names for native image resources.
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* Used by the GraalVM Feature to discover registered resources.
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*/
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public static Map<String, List<String>> getNativeImageResources() {
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return NATIVE_IMAGE_RESOURCES;
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}
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/**
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* Optional fallback class loader used when the class-based class loader
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* cannot locate a resource. This is typically set to the plugins class loader
@@ -135,6 +164,11 @@ public static File extract(Class clazz, String resourcePath) throws IOException,
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//File jarFile = new File(ResourcesExtractor.class.getProtectionDomain().getCodeSource().getLocation().getPath());
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if (findResource(clazz, resourcePath) == null) {
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// In GraalVM native images, directory resources are not available.
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// Try to find the welcome file and extract it.
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if (ImageInfo.inImageCode()) {
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return extractNativeImageResource(clazz, resourcePath);
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}
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LOG.warn("no resource to extract from path {}", resourcePath);
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throw new IllegalStateException("no resource to extract from path " + resourcePath);
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}
@@ -268,9 +302,44 @@ private static ClassLoader getClassLoader(Class clazz) {
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@SuppressWarnings("rawtypes")
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private static java.net.URL findResource(Class clazz, String resourcePath) {
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var url = getClassLoader(clazz).getResource(resourcePath);
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// In GraalVM native images, directory resources are not available.
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// Try common variations: trailing slash, or the welcome file.
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if (url == null) {
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url = getClassLoader(clazz).getResource(resourcePath + "/");
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}
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if (url == null && fallbackClassLoader != null) {
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url = fallbackClassLoader.getResource(resourcePath);
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}
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return url;
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}
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/**
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* Extracts resources from a native image where directory resources are not available.
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* Uses the resource map populated at build time by the GraalVM Feature.
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*/
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@SuppressWarnings("rawtypes")
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private static File extractNativeImageResource(Class clazz, String resourcePath) throws IOException {
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Path destinationDir = Files.createTempDirectory("restheart-");
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var files = NATIVE_IMAGE_RESOURCES.get(resourcePath);
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if (files != null) {
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for (String fileName : files) {
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var url = getClassLoader(clazz).getResource(resourcePath + "/" + fileName);
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if (url != null) {
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try (var is = url.openStream()) {
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Path dest = destinationDir.resolve(fileName);
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Files.copy(is, dest, StandardCopyOption.REPLACE_EXISTING);
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}
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}
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}
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}
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if (destinationDir.toFile().list().length == 0) {
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LOG.warn("no resource found under {} in native image", resourcePath);
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}
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return destinationDir.toFile();
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}
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}

‎core/src/main/java/org/restheart/graal/ResourcesScannerFeature.java‎

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@@ -0,0 +1,110 @@
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/*-
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* ========================LICENSE_START=================================
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* restheart-commons
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* %%
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* Copyright (C) 2014 - 2026 SoftInstigate
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* %%
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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* =========================LICENSE_END==================================
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*/
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package org.restheart.graal;
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import java.io.IOException;
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import java.net.URI;
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import java.net.URISyntaxException;
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import java.nio.file.FileSystem;
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import java.nio.file.FileSystems;
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import java.nio.file.FileVisitResult;
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import java.nio.file.Files;
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import java.nio.file.Path;
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import java.nio.file.SimpleFileVisitor;
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import java.nio.file.attribute.BasicFileAttributes;
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import java.util.Collections;
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import java.util.HashMap;
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import java.util.Map;
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import org.graalvm.nativeimage.hosted.Feature;
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import org.restheart.utils.ResourcesExtractor;
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/**
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* GraalVM Feature that scans the classpath at build time to discover
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* resource directories and their files. This information is stored in
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* {@link ResourcesExtractor} so that at runtime, embedded static resources
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* can be extracted even though {@code ClassLoader.getResources()} does
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* not work for directories in native images.
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*/
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public class ResourcesScannerFeature implements Feature {
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@Override
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public void beforeAnalysis(BeforeAnalysisAccess access) {
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// Scan the classpath for resource directories
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access.getApplicationClassPath().forEach(entry -> {
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try {
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if (Files.isDirectory(entry)) {
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scanDirectory(entry);
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} else if (entry.toString().endsWith(".jar")) {
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scanJar(entry);
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}
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} catch (Exception e) {
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// ignore errors for individual entries
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}
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});
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}
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private void scanDirectory(Path root) throws IOException {
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if (!Files.exists(root)) return;
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Files.walkFileTree(root, new SimpleFileVisitor<Path>() {
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@Override
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public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
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Path relative = root.relativize(file);
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String path = relative.toString().replace('\\', '/');
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int lastSlash = path.lastIndexOf('/');
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if (lastSlash > 0) {
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String dir = path.substring(0, lastSlash);
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String fileName = path.substring(lastSlash + 1);
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ResourcesExtractor.registerNativeImageResource(dir, fileName);
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}
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return FileVisitResult.CONTINUE;
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}
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});
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}
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private void scanJar(Path jarPath) throws IOException, URISyntaxException {
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Map<String, String> env = Collections.singletonMap("create", "false");
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URI uri = URI.create("jar:" + jarPath.toUri());
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try (FileSystem fs = FileSystems.newFileSystem(uri, env)) {
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Path root = fs.getPath("/");
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Files.walkFileTree(root, new SimpleFileVisitor<Path>() {
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@Override
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public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
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String path = file.toString().replace('\\', '/');
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if (path.startsWith("/")) path = path.substring(1);
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int lastSlash = path.lastIndexOf('/');
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if (lastSlash > 0) {
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String dir = path.substring(0, lastSlash);
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String fileName = path.substring(lastSlash + 1);
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ResourcesExtractor.registerNativeImageResource(dir, fileName);
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}
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return FileVisitResult.CONTINUE;
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}
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});
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}
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}
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@Override
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public String getDescription() {
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return "Scans classpath resources at build time for native image directory enumeration";
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}
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}

‎core/src/main/resources/META-INF/native-image/org.restheart/restheart-core/native-image.properties‎

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@@ -1,4 +1,4 @@
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Args = --initialize-at-build-time=org.restheart.plugins.PluginsScanner,io.github.classgraph.,nonapi.io.github.classgraph.,org.apache.commons.jxpath.ri.JXPathContextFactoryReferenceImpl,org.restheart.plugins.PluginDescriptor,org.restheart.plugins.FieldInjectionDescriptor,org.restheart.plugins.MethodInjectionDescriptor,com.github.benmanes.caffeine.cache \
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Args = --initialize-at-build-time=org.restheart.plugins.PluginsScanner,io.github.classgraph.,nonapi.io.github.classgraph.,org.apache.commons.jxpath.ri.JXPathContextFactoryReferenceImpl,org.restheart.plugins.PluginDescriptor,org.restheart.plugins.FieldInjectionDescriptor,org.restheart.plugins.MethodInjectionDescriptor,com.github.benmanes.caffeine.cache,org.restheart.utils.ResourcesExtractor,org.restheart.graal.ResourcesScannerFeature \
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--initialize-at-run-time=com.mongodb.UnixServerAddress,com.mongodb.internal.connection.SnappyCompressor \
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-J-Dfile.encoding=UTF-8 \
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-o restheart \
@@ -7,7 +7,7 @@ Args = --initialize-at-build-time=org.restheart.plugins.PluginsScanner,io.github
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--enable-https \
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--enable-url-protocols=http,https \
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--no-fallback \
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--features=org.restheart.graal.PluginsReflectionRegistrationFeature,org.restheart.graal.PluginsClassloaderInitFeature \
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--features=org.restheart.graal.PluginsReflectionRegistrationFeature,org.restheart.graal.PluginsClassloaderInitFeature,org.restheart.graal.ResourcesScannerFeature \
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--add-exports=java.net.http/jdk.internal.net.http=org.graalvm.truffle \
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--add-modules=org.graalvm.polyglot \
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--enable-native-access=org.graalvm.truffle

‎core/src/main/resources/META-INF/native-image/org.restheart/restheart-core/reachability-metadata.json‎

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{
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"glob": "email-templates/password-reset.html"
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},
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{
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"glob": "static/metrics"
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},
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{
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"glob": "static/metrics/**"
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}

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