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.Serializable;
  
  /**
   * Filters files based on size, can filter either smaller files or
   * files equal to or larger than a given threshold.
   * <p>
   * For example, to print all files and directories in the
   * current directory whose size is greater than 1 MB:
   *
   * <pre>
   * File dir = new File(".");
   * String[] files = dir.list( new SizeFileFilter(1024 * 1024) );
   * for ( int i = 0; i &lt; files.length; i++ ) {
   *     System.out.println(files[i]);
   * }
   * </pre>
   *
   * @author Rahul Akolkar
   * @version $Id: SizeFileFilter.java 1005099 2010-10-06 16:13:01Z niallp $
   * @since Commons IO 1.2
   * @see FileFilterUtils#sizeFileFilter(long)
   * @see FileFilterUtils#sizeFileFilter(long, boolean)
   * @see FileFilterUtils#sizeRangeFileFilter(long, long)
   */
  public class SizeFileFilter extends AbstractFileFilter implements Serializable {
  
      /** The size threshold. */
      private final long size;
      /** Whether the files accepted will be larger or smaller. */
      private final boolean acceptLarger;
  
      /**
       * Constructs a new size file filter for files equal to or 
       * larger than a certain size.
       *
       * @param size  the threshold size of the files
       * @throws IllegalArgumentException if the size is negative
       */
      public SizeFileFilter(long size) {
          this(size, true);
      }
  
      /**
       * Constructs a new size file filter for files based on a certain size
       * threshold.
       *
       * @param size  the threshold size of the files
       * @param acceptLarger  if true, files equal to or larger are accepted,
       * otherwise smaller ones (but not equal to)
       * @throws IllegalArgumentException if the size is negative
       */
      public SizeFileFilter(long size, boolean acceptLarger) {
          if (size < 0) {
              throw new IllegalArgumentException("The size must be non-negative");
          }
          this.size = size;
          this.acceptLarger = acceptLarger;
      }
  
      //-----------------------------------------------------------------------
      /**
       * Checks to see if the size of the file is favorable.
       * <p>
       * If size equals threshold and smaller files are required,
       * file <b>IS NOT</b> selected.
       * If size equals threshold and larger files are required,
       * file <b>IS</b> selected.
       *
       * @param file  the File to check
       * @return true if the filename matches
       */
      @Override
      public boolean accept(File file) {
          boolean smaller = file.length() < size;
          return acceptLarger ? !smaller : smaller;
      }
  
      /**
       * Provide a String representaion of this file filter.
       *
       * @return a String representaion
       */
      @Override
      public String toString() {
          String condition = acceptLarger ? ">=" : "<";
          return super.toString() + "(" + condition + size + ")";
      }
  
  }
  