src/main/java/org/apache/maven/plugins/pmd/ExcludeDuplicationsFromFile.java

package org.apache.maven.plugins.pmd;

/*
 * 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.io.FileReader;
import java.io.IOException;
import java.io.LineNumberReader;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.apache.commons.lang3.StringUtils;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugins.pmd.model.CpdFile;
import org.apache.maven.plugins.pmd.model.Duplication;

import net.sourceforge.pmd.cpd.Mark;
import net.sourceforge.pmd.cpd.Match;

/**
 * This class contains utility methods to load property files which define which files
 * should be excluded from the CPD duplication results.
 * See property <code>pmd.excludeFromFailureFile</code>.
 *
 * @author Andreas Dangel
 */
public class ExcludeDuplicationsFromFile implements ExcludeFromFile<Duplication>
{

    private final List<Set<String>> exclusionList = new ArrayList<>();

    @Override
    public boolean isExcludedFromFailure( final Duplication errorDetail )
    {
        final Set<String> uniquePaths = new HashSet<>();
        for ( final CpdFile cpdFile : errorDetail.getFiles() )
        {
            uniquePaths.add( cpdFile.getPath() );
        }
        return isExcludedFromFailure( uniquePaths );
    }

    /**
     * Checks whether the given {@link Match} is excluded.
     * Note: The exclusion must have been loaded before via {@link #loadExcludeFromFailuresData(String)}.
     * 
     * @param errorDetail the duplication to check
     * @return <code>true</code> if the given duplication should be excluded, <code>false</code> otherwise.
     */
    public boolean isExcludedFromFailure( final Match errorDetail )
    {
        final Set<String> uniquePaths = new HashSet<>();
        for ( Mark mark : errorDetail.getMarkSet() )
        {
            uniquePaths.add( mark.getFilename() );
        }
        return isExcludedFromFailure( uniquePaths );
    }

    private boolean isExcludedFromFailure( Set<String> uniquePaths )
    {
        for ( final Set<String> singleExclusionGroup : exclusionList )
        {
            if ( uniquePaths.size() == singleExclusionGroup.size()
                && duplicationExcludedByGroup( uniquePaths, singleExclusionGroup ) )
            {
                return true;
            }
        }
        return false;
    }

    private boolean duplicationExcludedByGroup( final Set<String> uniquePaths, final Set<String> singleExclusionGroup )
    {
        for ( final String path : uniquePaths )
        {
            if ( !fileExcludedByGroup( path, singleExclusionGroup ) )
            {
                return false;
            }
        }
        return true;
    }

    private boolean fileExcludedByGroup( final String path, final Set<String> singleExclusionGroup )
    {
        final String formattedPath = path.replace( '\\', '.' ).replace( '/', '.' );
        for ( final String className : singleExclusionGroup )
        {
            if ( formattedPath.contains( className ) )
            {
                return true;
            }
        }
        return false;
    }

    @Override
    public void loadExcludeFromFailuresData( final String excludeFromFailureFile )
            throws MojoExecutionException
    {
        if ( StringUtils.isEmpty( excludeFromFailureFile ) )
        {
            return;
        }

        try ( LineNumberReader reader = new LineNumberReader( new FileReader( excludeFromFailureFile ) ) )
        {
            String line;
            while ( ( line = reader.readLine() ) != null )
            {
                if ( !line.startsWith( "#" ) )
                {
                    exclusionList.add( createSetFromExclusionLine( line ) );
                }
            }
        }
        catch ( final IOException e )
        {
            throw new MojoExecutionException( "Cannot load file " + excludeFromFailureFile, e );
        }
    }

    private Set<String> createSetFromExclusionLine( final String line )
    {
        final Set<String> result = new HashSet<>();
        for ( final String className : line.split( "," ) )
        {
            result.add( className.trim() );
        }
        return result;
    }

    @Override
    public int countExclusions()
    {
        return exclusionList.size();
    }
}