code: /*
   * 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.
   */
  package org.apache.commons.io.filefilter;
  
  import java.io.File;
  import java.io.FileFilter;
  import java.io.FilenameFilter;
  import java.io.Serializable;
  
  /**
   * This class turns a Java FileFilter or FilenameFilter into an IO FileFilter.
   * 
   * @since Commons IO 1.0
   * @version $Revision: 1005099 $ $Date: 2010-10-06 17:13:01 +0100 (Wed, 06 Oct 2010) $
   * 
   * @author Stephen Colebourne
   * @see FileFilterUtils#asFileFilter(FileFilter)
   * @see FileFilterUtils#asFileFilter(FilenameFilter)
   */
  public class DelegateFileFilter extends AbstractFileFilter implements Serializable {
  
      /** The Filename filter */
      private final FilenameFilter filenameFilter;
      /** The File filter */
      private final FileFilter fileFilter;
  
      /**
       * Constructs a delegate file filter around an existing FilenameFilter.
       * 
       * @param filter  the filter to decorate
       */
      public DelegateFileFilter(FilenameFilter filter) {
          if (filter == null) {
              throw new IllegalArgumentException("The FilenameFilter must not be null");
          }
          this.filenameFilter = filter;
          this.fileFilter = null;
      }
  
      /**
       * Constructs a delegate file filter around an existing FileFilter.
       * 
       * @param filter  the filter to decorate
       */
      public DelegateFileFilter(FileFilter filter) {
          if (filter == null) {
              throw new IllegalArgumentException("The FileFilter must not be null");
          }
          this.fileFilter = filter;
          this.filenameFilter = null;
      }
  
      /**
       * Checks the filter.
       * 
       * @param file  the file to check
       * @return true if the filter matches
       */
      @Override
      public boolean accept(File file) {
          if (fileFilter != null) {
              return fileFilter.accept(file);
          } else {
              return super.accept(file);
          }
      }
  
      /**
       * Checks the filter.
       * 
       * @param dir  the directory
       * @param name  the filename in the directory
       * @return true if the filter matches
       */
      @Override
      public boolean accept(File dir, String name) {
          if (filenameFilter != null) {
              return filenameFilter.accept(dir, name);
          } else {
              return super.accept(dir, name);
          }
      }
  
      /**
       * Provide a String representaion of this file filter.
       *
       * @return a String representaion
       */
      @Override
      public String toString() {
          String delegate = (fileFilter != null ? fileFilter.toString() : filenameFilter.toString()); 
          return super.toString() + "(" + delegate + ")";
      }
      
  }
  