org.commonjava.maven.plugins.execroot.HighestBasedirGoal.java Source code

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Here is the source code for org.commonjava.maven.plugins.execroot.HighestBasedirGoal.java

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/*
 * Copyright 2011 Red Hat, Inc.
 * 
 * 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.commonjava.maven.plugins.execroot;

import org.apache.maven.plugin.ContextEnabled;
import org.apache.maven.plugin.Mojo;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.project.MavenProject;

import java.io.File;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Stack;

/**
 * @goal highest-basedir
 * @requiresProject true 
 * @phase initialize
 * 
 * Find the topmost directory in this Maven execution, and set it as a property.
 */
public class HighestBasedirGoal extends AbstractDirectoryGoal implements Mojo, ContextEnabled {

    public static final class PathComparator implements Comparator<File> {
        public int compare(final File first, final File second) {
            return first.getAbsolutePath().compareTo(second.getAbsolutePath());
        }
    }

    protected static final String HIGHEST_DIR_CONTEXT_KEY = "directories.highestDir";

    /**
     * @parameter default-value="${reactorProjects}"
     * @readonly
     */
    protected List<MavenProject> projects;

    /**
     * {@inheritDoc}
     * @throws MojoExecutionException 
     * @see org.commonjava.maven.plugins.execroot.AbstractDirectoryGoal#findDirectory()
     */
    @Override
    protected File findDirectory() throws MojoExecutionException {
        final Stack<MavenProject> toCheck = new Stack<MavenProject>();
        toCheck.addAll(projects);

        final List<File> files = new ArrayList<File>();
        while (!toCheck.isEmpty()) {
            final MavenProject p = toCheck.pop();
            if (p.getBasedir() == null) {
                // we've hit a parent that was resolved. Don't bother going higher up the hierarchy.
                continue;
            }

            if (!files.contains(p.getBasedir())) {
                // add to zero to maybe help pre-sort the paths...the shortest (parent) paths should end up near the
                // top.
                files.add(0, p.getBasedir());
            }

            if (p.getParent() != null) {
                toCheck.add(p.getParent());
            }
        }

        if (files.isEmpty()) {
            throw new MojoExecutionException("No project base directories found! Are you sure you're "
                    + "executing this on a valid Maven project?");
        }

        Collections.sort(files, new PathComparator());
        final File dir = files.get(0);

        if (files.size() > 1) {
            final File next = files.get(1);
            if (!next.getAbsolutePath().startsWith(dir.getAbsolutePath())) {
                throw new MojoExecutionException("Cannot find a single highest directory for this project set. "
                        + "First two candidates directories don't share a common root.");
            }
        }

        return dir;
    }

    /**
     * {@inheritDoc}
     * @see org.commonjava.maven.plugins.execroot.AbstractDirectoryGoal#getContextKey()
     */
    @Override
    protected String getContextKey() {
        return HIGHEST_DIR_CONTEXT_KEY;
    }

    /**
     * {@inheritDoc}
     * @see org.commonjava.maven.plugins.execroot.AbstractDirectoryGoal#getLogLabel()
     */
    @Override
    protected String getLogLabel() {
        return "Highest basedir";
    }

}