Java tutorial
package org.apache.maven.artifact.resolver; /* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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. */ import java.util.ArrayList; import java.util.Collections; import java.util.Iterator; import java.util.LinkedList; import java.util.List; import java.util.Set; import org.apache.maven.artifact.Artifact; import org.apache.maven.artifact.repository.ArtifactRepository; import org.apache.maven.artifact.resolver.filter.ArtifactFilter; import org.apache.maven.artifact.versioning.ArtifactVersion; import org.apache.maven.artifact.versioning.OverConstrainedVersionException; /** * ResolutionNode */ public class ResolutionNode { private Artifact artifact; private List<ResolutionNode> children; private final List<Object> parents; private final int depth; private final ResolutionNode parent; private final List<ArtifactRepository> remoteRepositories; private boolean active = true; private List<Artifact> trail; public ResolutionNode(Artifact artifact, List<ArtifactRepository> remoteRepositories) { this.artifact = artifact; this.remoteRepositories = remoteRepositories; depth = 0; parents = Collections.emptyList(); parent = null; } public ResolutionNode(Artifact artifact, List<ArtifactRepository> remoteRepositories, ResolutionNode parent) { this.artifact = artifact; this.remoteRepositories = remoteRepositories; depth = parent.depth + 1; parents = new ArrayList<>(); parents.addAll(parent.parents); parents.add(parent.getKey()); this.parent = parent; } public Artifact getArtifact() { return artifact; } public Object getKey() { return artifact.getDependencyConflictId(); } public void addDependencies(Set<Artifact> artifacts, List<ArtifactRepository> remoteRepositories, ArtifactFilter filter) throws CyclicDependencyException, OverConstrainedVersionException { if (artifacts != null && !artifacts.isEmpty()) { children = new ArrayList<>(artifacts.size()); for (Artifact a : artifacts) { if (parents.contains(a.getDependencyConflictId())) { a.setDependencyTrail(getDependencyTrail()); throw new CyclicDependencyException("A dependency has introduced a cycle", a); } children.add(new ResolutionNode(a, remoteRepositories, this)); } children = Collections.unmodifiableList(children); } else { children = Collections.emptyList(); } trail = null; } /** * @return {@link List} < {@link String} > with artifact ids * @throws OverConstrainedVersionException */ public List<String> getDependencyTrail() throws OverConstrainedVersionException { List<Artifact> trial = getTrail(); List<String> ret = new ArrayList<>(trial.size()); for (Artifact artifact : trial) { ret.add(artifact.getId()); } return ret; } private List<Artifact> getTrail() throws OverConstrainedVersionException { if (trail == null) { List<Artifact> ids = new LinkedList<>(); ResolutionNode node = this; while (node != null) { Artifact artifact = node.getArtifact(); if (artifact.getVersion() == null) { // set the recommended version ArtifactVersion selected = artifact.getSelectedVersion(); // MNG-2123: null is a valid response to getSelectedVersion, don't // assume it won't ever be. if (selected != null) { artifact.selectVersion(selected.toString()); } else { throw new OverConstrainedVersionException( "Unable to get a selected Version for " + artifact.getArtifactId(), artifact); } } ids.add(0, artifact); node = node.parent; } trail = ids; } return trail; } public boolean isResolved() { return children != null; } /** * Test whether the node is direct or transitive dependency. */ public boolean isChildOfRootNode() { return parent != null && parent.parent == null; } public Iterator<ResolutionNode> getChildrenIterator() { return children.iterator(); } public int getDepth() { return depth; } public List<ArtifactRepository> getRemoteRepositories() { return remoteRepositories; } public boolean isActive() { return active; } public void enable() { active = true; // TODO if it was null, we really need to go find them now... or is this taken care of by the ordering? if (children != null) { for (ResolutionNode node : children) { node.enable(); } } } public void disable() { active = false; if (children != null) { for (ResolutionNode node : children) { node.disable(); } } } public boolean filterTrail(ArtifactFilter filter) throws OverConstrainedVersionException { boolean success = true; if (filter != null) { for (Artifact artifact : getTrail()) { if (!filter.include(artifact)) { success = false; } } } return success; } @Override public String toString() { return artifact.toString() + " (" + depth + "; " + (active ? "enabled" : "disabled") + ")"; } public void setArtifact(Artifact artifact) { this.artifact = artifact; } }