org.jboss.modules.ResourceLoaderModuleFinder Maven / Gradle / Ivy
/*
* JBoss, Home of Professional Open Source.
* Copyright 2017 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* 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 org.jboss.modules;
import static org.jboss.modules.Utils.MODULES_DIR;
import static org.jboss.modules.Utils.MODULE_FILE;
import java.io.IOException;
import java.io.InputStream;
import org.jboss.modules.xml.ModuleXmlParser;
/**
* A module loader which loads modules which are stored inside the {@code modules} directory of a single JAR or JAR-like
* root.
*/
public final class ResourceLoaderModuleFinder implements ModuleFinder {
private final ResourceLoader resourceLoader;
private final String modulesDirectory;
private final NestedResourceRootFactory factory;
/**
* Construct a new instance. The given resource loader should support the nested {@link ResourceLoader#createSubloader(String, String)}
* operation if {@code <resource-root>} elements are to be supported in {@code module.xml} files found within
* the loader.
*
* @param resourceLoader the base resource loader to use (must not be {@code null})
* @param modulesDirectory the modules directory to use (must not be {@code null})
*/
public ResourceLoaderModuleFinder(final ResourceLoader resourceLoader, final String modulesDirectory) {
factory = new NestedResourceRootFactory(resourceLoader);
this.resourceLoader = resourceLoader;
this.modulesDirectory = modulesDirectory;
}
/**
* Construct a new instance. The given resource loader should support the nested {@link ResourceLoader#createSubloader(String, String)}
* operation if {@code <resource-root>} elements are to be supported in {@code module.xml} files found within
* the loader.
*
* @param resourceLoader the base resource loader to use (must not be {@code null})
*/
public ResourceLoaderModuleFinder(final ResourceLoader resourceLoader) {
this(resourceLoader, MODULES_DIR);
}
public ModuleSpec findModule(final String name, final ModuleLoader delegateLoader) throws ModuleLoadException {
final ResourceLoader resourceLoader = this.resourceLoader;
final String path = PathUtils.basicModuleNameToPath(name);
if (path == null) {
return null; // not valid, so not found
}
String basePath = modulesDirectory + "/" + path;
Resource moduleXmlResource = resourceLoader.getResource(basePath + "/" + MODULE_FILE);
if (moduleXmlResource == null) {
return null;
}
ModuleSpec moduleSpec;
try {
try (final InputStream inputStream = moduleXmlResource.openStream()) {
moduleSpec = ModuleXmlParser.parseModuleXml(factory, basePath, inputStream, moduleXmlResource.getName(), delegateLoader, name);
}
} catch (IOException e) {
throw new ModuleLoadException("Failed to read " + MODULE_FILE + " file", e);
}
return moduleSpec;
}
static class NestedResourceRootFactory implements ModuleXmlParser.ResourceRootFactory {
private final ResourceLoader resourceLoader;
NestedResourceRootFactory(final ResourceLoader resourceLoader) {
this.resourceLoader = resourceLoader;
}
public ResourceLoader createResourceLoader(final String rootPath, final String loaderPath, final String loaderName) throws IOException {
final ResourceLoader subloader = resourceLoader.createSubloader(rootPath + "/" + loaderPath, loaderName);
if (subloader == null) {
throw new IllegalArgumentException("Nested resource loaders not supported by " + resourceLoader);
}
return subloader;
}
}
}