/*

  * 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 < files.length; i++ ) {

  *     System.out.println(files[i]);

  * }

  * </pre>

  *

  * @version $Id: SizeFileFilter.java 1415850 2012-11-30 20:51:39Z ggregory $

  * @since 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(final 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(final long size, final 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(final File file) {

         final 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() {

         final String condition = acceptLarger ? ">=" : "<";

         return super.toString() + "(" + condition + size + ")";

     }

 }