com.google.cloud.tools.opensource.classpath.ClassPathBuilder Maven / Gradle / Ivy
/*
* Copyright 2019 Google LLC.
*
* 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 com.google.cloud.tools.opensource.classpath;
import com.google.cloud.tools.opensource.dependencies.Artifacts;
import com.google.cloud.tools.opensource.dependencies.DependencyGraph;
import com.google.cloud.tools.opensource.dependencies.DependencyGraphBuilder;
import com.google.cloud.tools.opensource.dependencies.DependencyPath;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.LinkedListMultimap;
import com.google.common.collect.Maps;
import java.nio.file.Path;
import java.util.List;
import java.util.Map;
import org.eclipse.aether.RepositoryException;
import org.eclipse.aether.artifact.Artifact;
/**
* Utility to build a class path (a list of jar files) through a dependency tree of Maven artifacts.
*
* @see
* Setting the Class Path: Specification Order
* @see
* Maven: Introduction to the Dependency Mechanism
*/
public class ClassPathBuilder {
/**
* Finds jar file paths for Maven artifacts and their transitive dependencies, using Maven's
* dependency mediation strategy.
*
* @param artifacts Maven artifacts to check
* @return list of absolute paths to jar files
* @throws RepositoryException when there is a problem retrieving jar files
*/
public static ImmutableList artifactsToClasspath(List artifacts)
throws RepositoryException {
// LinkedListMultimap keeps the key order as they were first added to the multimap
LinkedListMultimap multimap = artifactsToDependencyPaths(artifacts);
return ImmutableList.copyOf(multimap.keySet());
}
/**
* Finds jar file paths and dependency paths for Maven artifacts and their transitive
* dependencies. When there are multiple versions of an artifact in the dependency tree, the
* closest to the root in breadth-first order is picked up. This 'pick closest' strategy follows
* Maven's dependency mediation.
*
* The keys of the returned map represent jar files of {@code artifacts} and their transitive
* dependencies. The return value of {@link LinkedListMultimap#keySet()} preserves key iteration
* order.
*
*
The values of the returned map for a key (jar file) represent the different Maven dependency
* paths from {@code artifacts} to the Maven artifact of the jar file.
*
* @param artifacts Maven artifacts to check. They are treated as the root of the dependency tree.
* @return an ordered map of absolute paths of jar files to one or more Maven dependency paths
* @throws RepositoryException when there is a problem retrieving jar files
*/
public static LinkedListMultimap artifactsToDependencyPaths(
List artifacts) throws RepositoryException {
LinkedListMultimap multimap = LinkedListMultimap.create();
if (artifacts.isEmpty()) {
return multimap;
}
// dependencyGraph holds multiple versions for one artifact key (groupId:artifactId)
DependencyGraph dependencyGraph =
DependencyGraphBuilder.getStaticLinkageCheckDependencyGraph(artifacts);
List dependencyPaths = dependencyGraph.list();
// To remove duplicates on (groupId:artifactId) for dependency mediation
Map keyToFirstArtifactVersion = Maps.newHashMap();
for (DependencyPath dependencyPath : dependencyPaths) {
Artifact artifact = dependencyPath.getLeaf();
Path jarAbsolutePath = artifact.getFile().toPath().toAbsolutePath();
if (!jarAbsolutePath.toString().endsWith(".jar")) {
continue;
}
String artifactVersion = artifact.getVersion();
// groupId:artifactId
String dependencyMediationKey = Artifacts.makeKey(artifact);
String firstArtifactVersionForKey = keyToFirstArtifactVersion.get(dependencyMediationKey);
if (firstArtifactVersionForKey != null
&& !artifactVersion.equals(firstArtifactVersionForKey)) {
// Not adding this artifact if different version of the artifact (: as
// key) is already in `multimap`.
// As `dependencyPaths` elements are in level order (breadth-first), this first-wins
// strategy follows Maven's dependency mediation.
// TODO(#309): add Gradle's dependency mediation
continue;
}
keyToFirstArtifactVersion.put(dependencyMediationKey, artifact.getVersion());
// When finding the key (groupId:artifactId) first time, or additional dependency path to
// the artifact of the same version is encountered, adds the dependency path to `multimap`.
multimap.put(jarAbsolutePath, dependencyPath);
}
return multimap;
}
}