org.jboss.modules.VersionDetection Maven / Gradle / Ivy
/*
* JBoss, Home of Professional Open Source.
* Copyright 2018 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 java.io.IOException;
import java.io.InputStream;
import java.util.jar.Attributes;
import java.util.jar.Manifest;
/**
* A utility class to assist with detecting the version of a resource root or collection of resource roots.
*/
public final class VersionDetection {
private VersionDetection() {}
/**
* Attempt to guess the version of a resource loader.
*
* @param resourceLoader the resource loader to check (must not be {@code null})
* @return the version, or {@code null} if no version could be determined
* @throws IOException if necessary resource(s) failed to load
*/
public static Version detectVersion(ResourceLoader resourceLoader) throws IOException {
final Resource resource = resourceLoader.getResource("META-INF/MANIFEST.MF");
if (resource != null) {
Manifest manifest;
try (InputStream is = resource.openStream()) {
manifest = new Manifest(is);
}
final Attributes mainAttributes = manifest.getMainAttributes();
final String versionString = mainAttributes.getValue(Attributes.Name.IMPLEMENTATION_VERSION);
if (versionString != null) try {
return Version.parse(versionString);
} catch (IllegalArgumentException ignored) {
}
}
return null;
}
}