se.jguru.nazgul.tools.plugin.checkstyle.exec.DefaultCheckstyleExecutor.java Source code

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package se.jguru.nazgul.tools.plugin.checkstyle.exec;

/*
 * 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 com.puppycrawl.tools.checkstyle.Checker;
import com.puppycrawl.tools.checkstyle.ConfigurationLoader;
import com.puppycrawl.tools.checkstyle.DefaultConfiguration;
import com.puppycrawl.tools.checkstyle.PackageNamesLoader;
import com.puppycrawl.tools.checkstyle.PropertiesExpander;
import com.puppycrawl.tools.checkstyle.api.AuditListener;
import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
import com.puppycrawl.tools.checkstyle.api.Configuration;
import com.puppycrawl.tools.checkstyle.api.FilterSet;
import com.puppycrawl.tools.checkstyle.filters.SuppressionsLoader;
import org.apache.commons.io.IOUtils;
import org.apache.maven.artifact.Artifact;
import org.apache.maven.artifact.DependencyResolutionRequiredException;
import org.apache.maven.model.Resource;
import org.apache.maven.project.MavenProject;
import org.codehaus.plexus.component.annotations.Component;
import org.codehaus.plexus.component.annotations.Requirement;
import org.codehaus.plexus.logging.AbstractLogEnabled;
import org.codehaus.plexus.resource.ResourceManager;
import org.codehaus.plexus.resource.loader.FileResourceCreationException;
import org.codehaus.plexus.resource.loader.FileResourceLoader;
import org.codehaus.plexus.resource.loader.ResourceNotFoundException;
import org.codehaus.plexus.util.FileUtils;
import org.codehaus.plexus.util.StringUtils;

import java.io.ByteArrayInputStream;
import java.io.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;

/**
 * @author Olivier Lamy
 * @version $Id$
 * @since 2.5
 */
@Component(role = CheckstyleExecutor.class, hint = "default", instantiationStrategy = "per-lookup")
public class DefaultCheckstyleExecutor extends AbstractLogEnabled implements CheckstyleExecutor {

    @Requirement(hint = "default")
    private ResourceManager locator;

    @Requirement(hint = "license")
    private ResourceManager licenseLocator;

    public CheckstyleResults executeCheckstyle(CheckstyleExecutorRequest request)
            throws CheckstyleExecutorException, CheckstyleException {

        // Checkstyle will always use the context classloader in order
        // to load resources (dtds), so we have to fix it
        // olamy this hack is not anymore needed in Maven 3.x
        ClassLoader checkstyleClassLoader = PackageNamesLoader.class.getClassLoader();
        Thread.currentThread().setContextClassLoader(checkstyleClassLoader);

        if (getLogger().isDebugEnabled()) {
            getLogger().debug("executeCheckstyle start headerLocation : " + request.getHeaderLocation());
        }

        MavenProject project = request.getProject();

        configureResourceLocator(locator, request, null);

        configureResourceLocator(licenseLocator, request, request.getLicenseArtifacts());

        // Config is less critical than License, locator can still be used.
        // configureResourceLocator( configurationLocator, request, request.getConfigurationArtifacts() );

        List<File> files;
        try {
            files = getFilesToProcess(request);
        } catch (IOException e) {
            throw new CheckstyleExecutorException("Error getting files to process", e);
        }

        final String suppressionsFilePath = getSuppressionsFilePath(request);
        FilterSet filterSet = getSuppressionsFilterSet(suppressionsFilePath);

        Checker checker = new Checker();

        // setup classloader, needed to avoid "Unable to get class information for ..." errors
        List<String> classPathStrings = new ArrayList<>();
        List<String> outputDirectories = new ArrayList<>();

        // stand-alone
        Collection<File> sourceDirectories = null;
        Collection<File> testSourceDirectories = request.getTestSourceDirectories();

        // aggregator
        Map<MavenProject, Collection<File>> sourceDirectoriesByProject = new HashMap<>();
        Map<MavenProject, Collection<File>> testSourceDirectoriesByProject = new HashMap<>();

        if (request.isAggregate()) {
            for (MavenProject childProject : request.getReactorProjects()) {
                sourceDirectories = new ArrayList<>(childProject.getCompileSourceRoots().size());
                List<String> compileSourceRoots = childProject.getCompileSourceRoots();
                for (String compileSourceRoot : compileSourceRoots) {
                    sourceDirectories.add(new File(compileSourceRoot));
                }
                sourceDirectoriesByProject.put(childProject, sourceDirectories);

                testSourceDirectories = new ArrayList<>(childProject.getTestCompileSourceRoots().size());
                List<String> testCompileSourceRoots = childProject.getTestCompileSourceRoots();
                for (String testCompileSourceRoot : testCompileSourceRoots) {
                    testSourceDirectories.add(new File(testCompileSourceRoot));
                }
                testSourceDirectoriesByProject.put(childProject, testSourceDirectories);

                prepareCheckstylePaths(request, childProject, classPathStrings, outputDirectories,
                        sourceDirectories, testSourceDirectories);
            }
        } else {
            sourceDirectories = request.getSourceDirectories();
            prepareCheckstylePaths(request, project, classPathStrings, outputDirectories, sourceDirectories,
                    testSourceDirectories);
        }

        final List<URL> urls = new ArrayList<>(classPathStrings.size());

        for (String path : classPathStrings) {
            try {
                urls.add(new File(path).toURL());
            } catch (MalformedURLException e) {
                throw new CheckstyleExecutorException(e.getMessage(), e);
            }
        }

        for (String outputDirectoryString : outputDirectories) {
            try {
                if (outputDirectoryString != null) {
                    File outputDirectoryFile = new File(outputDirectoryString);
                    if (outputDirectoryFile.exists()) {
                        URL outputDirectoryUrl = outputDirectoryFile.toURL();
                        getLogger().debug("Adding the outputDirectory " + outputDirectoryUrl.toString()
                                + " to the Checkstyle class path");
                        urls.add(outputDirectoryUrl);
                    }
                }
            } catch (MalformedURLException e) {
                throw new CheckstyleExecutorException(e.getMessage(), e);
            }
        }

        URLClassLoader projectClassLoader = AccessController.doPrivileged(new PrivilegedAction<URLClassLoader>() {
            public URLClassLoader run() {
                return new URLClassLoader(urls.toArray(new URL[urls.size()]), null);
            }
        });

        checker.setClassLoader(projectClassLoader);

        checker.setModuleClassLoader(Thread.currentThread().getContextClassLoader());

        if (filterSet != null) {
            checker.addFilter(filterSet);
        }
        Configuration configuration = getConfiguration(request);
        checker.configure(configuration);

        AuditListener listener = request.getListener();

        if (listener != null) {
            checker.addListener(listener);
        }

        if (request.isConsoleOutput()) {
            checker.addListener(request.getConsoleListener());
        }

        CheckstyleCheckerListener checkerListener = new CheckstyleCheckerListener(configuration);
        if (request.isAggregate()) {
            for (MavenProject childProject : request.getReactorProjects()) {
                sourceDirectories = sourceDirectoriesByProject.get(childProject);
                testSourceDirectories = testSourceDirectoriesByProject.get(childProject);
                addSourceDirectory(checkerListener, sourceDirectories, testSourceDirectories,
                        childProject.getResources(), request);
            }
        } else {
            addSourceDirectory(checkerListener, sourceDirectories, testSourceDirectories, request.getResources(),
                    request);
        }

        checker.addListener(checkerListener);

        int nbErrors = checker.process(files);

        checker.destroy();

        if (projectClassLoader instanceof Closeable) {
            try {
                ((Closeable) projectClassLoader).close();
            } catch (IOException ex) {
                // Nothing we can do - and not detrimental to the build (save running out of file handles).
                getLogger().info("Failed to close custom Classloader - this indicated a bug in the code.", ex);
            }
        }

        if (request.getStringOutputStream() != null) {
            String message = request.getStringOutputStream().toString().trim();

            if (message.length() > 0) {
                getLogger().info(message);
            }
        }

        if (nbErrors > 0) {
            StringBuilder message = new StringBuilder("There ");
            if (nbErrors == 1) {
                message.append("is");
            } else {
                message.append("are");
            }
            message.append(" ");
            message.append(nbErrors);
            message.append(" error");
            if (nbErrors != 1) {
                message.append("s");
            }
            message.append(" reported by Checkstyle");
            String version = getCheckstyleVersion();
            if (version != null) {
                message.append(" ");
                message.append(version);
            }
            message.append(" with ");
            message.append(request.getConfigLocation());
            message.append(" ruleset.");

            if (request.isFailsOnError()) {
                // TODO: should be a failure, not an error. Report is not meant to
                // throw an exception here (so site would
                // work regardless of config), but should record this information
                throw new CheckstyleExecutorException(message.toString());
            } else {
                getLogger().info(message.toString());
            }
        }

        return checkerListener.getResults();
    }

    protected void addSourceDirectory(CheckstyleCheckerListener sinkListener, Collection<File> sourceDirectories,
            Collection<File> testSourceDirectories, List<Resource> resources, CheckstyleExecutorRequest request) {
        if (sourceDirectories != null) {
            for (File sourceDirectory : sourceDirectories) {
                if (sourceDirectory.exists()) {
                    sinkListener.addSourceDirectory(sourceDirectory);
                }
            }
        }

        if (request.isIncludeTestSourceDirectory() && (testSourceDirectories != null)) {
            for (File testSourceDirectory : testSourceDirectories) {
                if (testSourceDirectory.isDirectory()) {
                    sinkListener.addSourceDirectory(testSourceDirectory);
                }
            }
        }

        if (resources != null) {
            for (Resource resource : resources) {
                if (resource.getDirectory() != null) {
                    File resourcesDirectory = new File(resource.getDirectory());
                    if (resourcesDirectory.exists() && resourcesDirectory.isDirectory()) {
                        sinkListener.addSourceDirectory(resourcesDirectory);
                        getLogger().debug(
                                "Added '" + resourcesDirectory.getAbsolutePath() + "' as a source directory.");
                    }
                }
            }
        }
    }

    public Configuration getConfiguration(CheckstyleExecutorRequest request) throws CheckstyleExecutorException {
        try {
            // Checkstyle will always use the context classloader in order
            // to load resources (dtds),
            // so we have to fix it
            ClassLoader checkstyleClassLoader = PackageNamesLoader.class.getClassLoader();
            Thread.currentThread().setContextClassLoader(checkstyleClassLoader);
            String configFile = getConfigFile(request);
            Properties overridingProperties = getOverridingProperties(request);
            Configuration config = ConfigurationLoader.loadConfiguration(configFile,
                    new PropertiesExpander(overridingProperties));
            String effectiveEncoding = StringUtils.isNotEmpty(request.getEncoding()) ? request.getEncoding()
                    : System.getProperty("file.encoding", "UTF-8");

            if (StringUtils.isEmpty(request.getEncoding())) {
                getLogger().warn("File encoding has not been set, using platform encoding " + effectiveEncoding
                        + ", i.e. build is platform dependent!");
            }

            if ("Checker".equals(config.getName())
                    || "com.puppycrawl.tools.checkstyle.Checker".equals(config.getName())) {
                if (config instanceof DefaultConfiguration) {
                    // MCHECKSTYLE-173 Only add the "charset" attribute if it has not been set
                    try {
                        if (config.getAttribute("charset") == null) {
                            ((DefaultConfiguration) config).addAttribute("charset", effectiveEncoding);
                        }
                    } catch (CheckstyleException ex) {
                        // Checkstyle 5.4+ throws an exception when trying to access an attribute that doesn't exist
                        ((DefaultConfiguration) config).addAttribute("charset", effectiveEncoding);
                    }
                } else {
                    getLogger().warn("Failed to configure file encoding on module " + config);
                }
            }
            Configuration[] modules = config.getChildren();
            for (Configuration module : modules) {
                if ("TreeWalker".equals(module.getName())
                        || "com.puppycrawl.tools.checkstyle.TreeWalker".equals(module.getName())) {
                    if (module instanceof DefaultConfiguration) {
                        // MCHECKSTYLE-132 DefaultConfiguration addAttribute has changed in checkstyle 5.3
                        try {
                            if (module.getAttribute("cacheFile") == null) {
                                ((DefaultConfiguration) module).addAttribute("cacheFile", request.getCacheFile());
                            }
                        } catch (CheckstyleException ex) {
                            // MCHECKSTYLE-159 - checkstyle 5.4 throws an exception instead of return null if
                            // "cacheFile"
                            // doesn't exist
                            ((DefaultConfiguration) module).addAttribute("cacheFile", request.getCacheFile());
                        }
                    } else {
                        getLogger().warn("Failed to configure cache file on module " + module);
                    }
                }
            }
            return config;
        } catch (CheckstyleException e) {
            throw new CheckstyleExecutorException("Failed during checkstyle configuration", e);
        }
    }

    private void prepareCheckstylePaths(CheckstyleExecutorRequest request, MavenProject project,
            List<String> classPathStrings, List<String> outputDirectories, Collection<File> sourceDirectories,
            Collection<File> testSourceDirectories) throws CheckstyleExecutorException {
        try {
            outputDirectories.add(project.getBuild().getOutputDirectory());

            if (request.isIncludeTestSourceDirectory() && (testSourceDirectories != null)
                    && anyDirectoryExists(testSourceDirectories)) {
                classPathStrings.addAll(project.getTestClasspathElements());
                outputDirectories.add(project.getBuild().getTestOutputDirectory());
            } else {
                classPathStrings.addAll(project.getCompileClasspathElements());
            }
        } catch (DependencyResolutionRequiredException e) {
            throw new CheckstyleExecutorException(e.getMessage(), e);
        }
    }

    private boolean anyDirectoryExists(Collection<File> files) {
        for (File file : files) {
            if (file.isDirectory()) {
                return true;
            }
        }
        return false;
    }

    /**
     * Get the effective Checkstyle version at runtime.
     *
     * @return the MANIFEST implementation version of Checkstyle API package (can be <code>null</code>)
     * @todo Copied from CheckstyleReportGenerator - move to a utility class
     */
    private String getCheckstyleVersion() {
        Package checkstyleApiPackage = Configuration.class.getPackage();

        return (checkstyleApiPackage == null) ? null : checkstyleApiPackage.getImplementationVersion();
    }

    private Properties getOverridingProperties(CheckstyleExecutorRequest request)
            throws CheckstyleExecutorException {
        Properties p = new Properties();
        InputStream in = null;
        try {
            if (request.getPropertiesLocation() != null) {
                if (getLogger().isDebugEnabled()) {
                    getLogger().debug("request.getPropertiesLocation() " + request.getPropertiesLocation());
                }

                File propertiesFile = locator.getResourceAsFile(request.getPropertiesLocation(),
                        "checkstyle-checker.properties");

                if (propertiesFile != null) {
                    in = new FileInputStream(propertiesFile);
                    p.load(in);
                    in.close();
                    in = null;
                }
            }

            if (StringUtils.isNotEmpty(request.getPropertyExpansion())) {
                String propertyExpansion = request.getPropertyExpansion();
                // Convert \ to \\, so that p.load will convert it back properly
                propertyExpansion = StringUtils.replace(propertyExpansion, "\\", "\\\\");
                p.load(new ByteArrayInputStream(propertyExpansion.getBytes()));
            }

            // Workaround for MCHECKSTYLE-48
            // Make sure that "config/maven-header.txt" is the default value
            // for headerLocation, if configLocation="config/maven_checks.xml"
            String headerLocation = request.getHeaderLocation();
            if ("config/maven_checks.xml".equals(request.getConfigLocation())) {

                if ("LICENSE.txt".equals(request.getHeaderLocation())) {
                    headerLocation = "config/maven-header.txt";
                }
            }
            if (getLogger().isDebugEnabled()) {
                getLogger().debug("headerLocation " + headerLocation);
            }

            if (StringUtils.isNotEmpty(headerLocation)) {
                try {
                    File headerFile = licenseLocator.getResourceAsFile(headerLocation, "checkstyle-header.txt");

                    if (headerFile != null) {
                        p.setProperty("checkstyle.header.file", headerFile.getAbsolutePath());
                    }
                } catch (FileResourceCreationException | ResourceNotFoundException e) {
                    getLogger().debug("Unable to process header location: " + headerLocation);
                    getLogger().debug("Checkstyle will throw exception if ${checkstyle.header.file} is used");
                }
            }

            if (request.getCacheFile() != null) {
                p.setProperty("checkstyle.cache.file", request.getCacheFile());
            }
        } catch (IOException | ResourceNotFoundException | FileResourceCreationException e) {
            throw new CheckstyleExecutorException("Failed to get overriding properties", e);
        } finally {
            IOUtils.closeQuietly(in);
        }
        if (request.getSuppressionsFileExpression() != null) {
            String suppressionsFilePath = getSuppressionsFilePath(request);

            if (suppressionsFilePath != null) {
                p.setProperty(request.getSuppressionsFileExpression(), suppressionsFilePath);
            }
        }

        return p;
    }

    private List<File> getFilesToProcess(CheckstyleExecutorRequest request) throws IOException {
        StringBuilder excludesStr = new StringBuilder();

        if (StringUtils.isNotEmpty(request.getExcludes())) {
            excludesStr.append(request.getExcludes());
        }

        String[] defaultExcludes = FileUtils.getDefaultExcludes();
        for (String defaultExclude : defaultExcludes) {
            if (excludesStr.length() > 0) {
                excludesStr.append(",");
            }

            excludesStr.append(defaultExclude);
        }

        Set<File> files = new LinkedHashSet<>();
        if (request.isAggregate()) {
            for (MavenProject project : request.getReactorProjects()) {
                Set<File> sourceDirectories = new LinkedHashSet<>();

                // CompileSourceRoots are absolute paths
                List<String> compileSourceRoots = project.getCompileSourceRoots();
                for (String compileSourceRoot : compileSourceRoots) {
                    sourceDirectories.add(new File(compileSourceRoot));
                }

                Set<File> testSourceDirectories = new LinkedHashSet<>();
                // CompileSourceRoots are absolute paths
                List<String> testCompileSourceRoots = project.getTestCompileSourceRoots();
                for (String testCompileSourceRoot : testCompileSourceRoots) {
                    testSourceDirectories.add(new File(testCompileSourceRoot));
                }

                addFilesToProcess(request, sourceDirectories, project.getResources(), project.getTestResources(),
                        files, testSourceDirectories);
            }
        } else {
            Collection<File> sourceDirectories = request.getSourceDirectories();
            addFilesToProcess(request, sourceDirectories, request.getResources(), request.getTestResources(), files,
                    request.getTestSourceDirectories());
        }

        getLogger().debug("Added " + files.size() + " files to process.");

        return new ArrayList<>(files);
    }

    private void addFilesToProcess(CheckstyleExecutorRequest request, Collection<File> sourceDirectories,
            List<Resource> resources, List<Resource> testResources, Collection<File> files,
            Collection<File> testSourceDirectories) throws IOException {
        if (sourceDirectories != null) {
            for (File sourceDirectory : sourceDirectories) {
                if (sourceDirectory.isDirectory()) {
                    final List<File> sourceFiles = FileUtils.getFiles(sourceDirectory, request.getIncludes(),
                            request.getExcludes());
                    files.addAll(sourceFiles);
                    getLogger().debug("Added " + sourceFiles.size() + " source files found in '"
                            + sourceDirectory.getAbsolutePath() + "'.");
                }
            }
        }

        if (request.isIncludeTestSourceDirectory() && testSourceDirectories != null) {
            for (File testSourceDirectory : testSourceDirectories) {
                if (testSourceDirectory.isDirectory()) {
                    final List<File> testSourceFiles = FileUtils.getFiles(testSourceDirectory,
                            request.getIncludes(), request.getExcludes());

                    files.addAll(testSourceFiles);
                    getLogger().debug("Added " + testSourceFiles.size() + " test source files found in '"
                            + testSourceDirectory.getAbsolutePath() + "'.");
                }
            }
        }

        if (resources != null && request.isIncludeResources()) {
            addResourceFilesToProcess(request, resources, files);
        } else {
            getLogger().debug("No resources found in this project.");
        }

        if (testResources != null && request.isIncludeTestResources()) {
            addResourceFilesToProcess(request, testResources, files);
        } else {
            getLogger().debug("No test resources found in this project.");
        }
    }

    private void addResourceFilesToProcess(CheckstyleExecutorRequest request, List<Resource> resources,
            Collection<File> files) throws IOException {
        for (Resource resource : resources) {
            if (resource.getDirectory() != null) {
                File resourcesDirectory = new File(resource.getDirectory());
                if (resourcesDirectory.isDirectory()) {
                    String includes = request.getResourceIncludes();
                    String excludes = request.getResourceExcludes();

                    // MCHECKSTYLE-214: Only with project-root respect in/excludes, otherwise you'll get every file
                    if (resourcesDirectory.equals(request.getProject().getBasedir())) {
                        String resourceIncludes = StringUtils.join(resource.getIncludes().iterator(), ",");
                        if (StringUtils.isEmpty(includes)) {
                            includes = resourceIncludes;
                        } else {
                            includes += "," + resourceIncludes;
                        }

                        String resourceExcludes = StringUtils.join(resource.getExcludes().iterator(), ",");
                        if (StringUtils.isEmpty(excludes)) {
                            excludes = resourceExcludes;
                        } else {
                            excludes += "," + resourceExcludes;
                        }
                    }

                    List<File> resourceFiles = FileUtils.getFiles(resourcesDirectory, includes, excludes);
                    files.addAll(resourceFiles);
                    getLogger().debug("Added " + resourceFiles.size() + " resource files found in '"
                            + resourcesDirectory.getAbsolutePath() + "'.");
                } else {
                    getLogger().debug("The resources directory '" + resourcesDirectory.getAbsolutePath()
                            + "' does not exist or is not a directory.");
                }
            }
        }
    }

    private FilterSet getSuppressionsFilterSet(final String suppressionsFilePath)
            throws CheckstyleExecutorException {
        if (suppressionsFilePath == null) {
            return null;
        }

        try {
            return SuppressionsLoader.loadSuppressions(suppressionsFilePath);
        } catch (CheckstyleException ce) {
            throw new CheckstyleExecutorException("Failed to load suppressions file from: " + suppressionsFilePath,
                    ce);
        }
    }

    private String getSuppressionsFilePath(final CheckstyleExecutorRequest request)
            throws CheckstyleExecutorException {
        final String suppressionsLocation = request.getSuppressionsLocation();
        if (StringUtils.isEmpty(suppressionsLocation)) {
            return null;
        }

        try {
            File suppressionsFile = locator.getResourceAsFile(suppressionsLocation, "checkstyle-suppressions.xml");
            return suppressionsFile == null ? null : suppressionsFile.getAbsolutePath();
        } catch (ResourceNotFoundException e) {
            throw new CheckstyleExecutorException(
                    "Unable to find suppressions file at location: " + suppressionsLocation, e);
        } catch (FileResourceCreationException e) {
            throw new CheckstyleExecutorException(
                    "Unable to process suppressions file location: " + suppressionsLocation, e);
        }
    }

    private String getConfigFile(CheckstyleExecutorRequest request) throws CheckstyleExecutorException {
        try {
            if (getLogger().isDebugEnabled()) {
                getLogger().debug("request.getConfigLocation() " + request.getConfigLocation());
            }

            File configFile = locator.getResourceAsFile(request.getConfigLocation(), "checkstyle-checker.xml");
            if (configFile == null) {
                throw new CheckstyleExecutorException(
                        "Unable to process config location: " + request.getConfigLocation());
            }
            return configFile.getAbsolutePath();
        } catch (ResourceNotFoundException e) {
            throw new CheckstyleExecutorException(
                    "Unable to find configuration file at location: " + request.getConfigLocation(), e);
        } catch (FileResourceCreationException e) {
            throw new CheckstyleExecutorException(
                    "Unable to process configuration file at location: " + request.getConfigLocation(), e);
        }

    }

    /**
     * Configures search paths in the resource locator.
     * This method should only be called once per execution.
     *
     * @param request executor request data.
     */
    private void configureResourceLocator(final ResourceManager resourceManager,
            final CheckstyleExecutorRequest request, final List<Artifact> additionalArtifacts) {
        final MavenProject project = request.getProject();
        resourceManager.setOutputDirectory(new File(project.getBuild().getDirectory()));

        // Recurse up the parent hierarchy and add project directories to the search roots
        MavenProject parent = project;
        while (parent != null && parent.getFile() != null) {
            // MCHECKSTYLE-131 ( olamy ) I don't like this hack.
            // (dkulp) Me either.   It really pollutes the location stuff
            // by allowing searches of stuff outside the current module.
            File dir = parent.getFile().getParentFile();
            resourceManager.addSearchPath(FileResourceLoader.ID, dir.getAbsolutePath());
            parent = parent.getParent();
        }
        resourceManager.addSearchPath("url", "");

        // MCHECKSTYLE-225: load licenses from additional artifacts, not from classpath
        if (additionalArtifacts != null) {
            for (Artifact licenseArtifact : additionalArtifacts) {
                try {
                    // MCHECKSTYLE-287, MCHECKSTYLE-294: Ignore null licenseArtifacts ...
                    if (licenseArtifact != null) {
                        if (getLogger().isDebugEnabled()) {
                            getLogger().debug("Adding licenceArtifact [" + licenseArtifact.getGroupId() + ":"
                                    + licenseArtifact.getArtifactId() + ":" + licenseArtifact.getVersion()
                                    + "] to resourceManager.");
                        }
                        resourceManager.addSearchPath("jar", "jar:" + licenseArtifact.getFile().toURI().toURL());
                    }
                } catch (MalformedURLException e) {
                    // noop
                }
            }
        }
    }
}