code: /**
   * This file is part of Eclipse Steady.
   *
   * 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.
   *
   * SPDX-License-Identifier: Apache-2.0
   * SPDX-FileCopyrightText: Copyright (c) 2018-2020 SAP SE or an SAP affiliate company and Eclipse Steady contributors
   */
  package org.eclipse.steady.shared.util;
  
  import java.nio.file.FileVisitOption;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.nio.file.SimpleFileVisitor;
  import java.nio.file.attribute.BasicFileAttributes;
  import java.util.HashSet;
  import java.util.Set;
  import java.util.TreeSet;
  
  import javax.validation.constraints.NotNull;
  
  import org.apache.logging.log4j.Logger;
  
  /**
   * <p>AbstractFileSearch class.</p>
   */
  public class AbstractFileSearch extends SimpleFileVisitor<Path> {
  
    private static Logger log = null;
  
    private static final Logger getLog() {
      if (AbstractFileSearch.log == null)
        AbstractFileSearch.log =
            org.apache.logging.log4j.LogManager.getLogger(AbstractFileSearch.class);
      return AbstractFileSearch.log;
    }
  
    private final Set<Path> files = new TreeSet<Path>();
  
    /**
     * <p>foundFile.</p>
     *
     * @param _p a {@link java.nio.file.Path} object.
     * @return a boolean.
     */
    protected boolean foundFile(Path _p) {
      return this.files.contains(_p);
    }
  
    /**
     * <p>addFile.</p>
     *
     * @param _p a {@link java.nio.file.Path} object.
     */
    protected void addFile(Path _p) {
      this.files.add(_p);
    }
  
    /**
     * Clears previous search results.
     */
    public void clear() {
      this.files.clear();
    }
  
    /**
     * Starts searching for files in the given paths, with unlimited depth.
     *
     * @param _paths the FS path to search in
     * @return a set of paths for all files found
     */
    public Set<Path> search(Set<Path> _paths) {
      return this.search(_paths, java.lang.Integer.MAX_VALUE);
    }
  
    /**
     * Starts searching for files in the given paths.
     *
     * @param _paths one or multiple FS paths to search in
     * @param _depth the depth of nested directories to search in
     * @return a set of paths for all files found
     */
    public Set<Path> search(Set<Path> _paths, int _depth) {
      for (Path p : _paths) this.search(p, _depth);
      AbstractFileSearch.getLog()
          .info(
              "Found a total of [" + this.files.size() + "] files in [" + _paths.size() + "] paths");
      return this.files;
    }
  
    /**
     * Starts searching for files in the given path, with unlimited depth.
     *
     * @param _p the FS path to search in
     * @return a set of paths for all files found
     */
    public Set<Path> search(Path _p) {
      return this.search(_p, java.lang.Integer.MAX_VALUE);
    }
  
    /**
     * Starts searching for files in the given path, up to the specified depth.
     *
     * @param _p the FS path to search in
     * @param _depth the depth of nested directories to search in
     * @return a set of paths for all files found
     */
    public Set<Path> search(@NotNull Path _p, int _depth) {
      try {
        if (Files.isDirectory(_p))
          Files.walkFileTree(_p, new HashSet<FileVisitOption>(), _depth, this);
        else if (Files.isRegularFile(_p))
          this.visitFile(_p, Files.readAttributes(_p, BasicFileAttributes.class));
      } catch (Exception e) {
        AbstractFileSearch.getLog()
            .error("Error while analyzing path [" + _p + "]: " + e.getMessage());
      }
      if (_p.isAbsolute())
        AbstractFileSearch.getLog()
            .info(
                "Found ["
                    + this.files.size()
                    + "] files in absolute path ["
                    + _p.toAbsolutePath()
                    + "]");
      else
        AbstractFileSearch.getLog()
            .info(
                "Found ["
                    + this.files.size()
                    + "] files in relative path ["
                    + _p
                    + "], i.e., absolute path ["
                    + _p.toAbsolutePath()
                    + "]");
      return this.files;
    }
  }
  