/*

  * 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;

 /**

  * This filter accepts <code>File</code>s that can be read.

  * <p>

  * Example, showing how to print out a list of the

  * current directory's <i>readable</i> files:

  *

  * <pre>

  * File dir = new File(".");

  * String[] files = dir.list( CanReadFileFilter.CAN_READ );

  * for ( int i = 0; i < files.length; i++ ) {

  *     System.out.println(files[i]);

  * }

  * </pre>

  *

  * <p>

  * Example, showing how to print out a list of the

  * current directory's <i>un-readable</i> files:

  *

  * <pre>

  * File dir = new File(".");

  * String[] files = dir.list( CanReadFileFilter.CANNOT_READ );

  * for ( int i = 0; i < files.length; i++ ) {

  *     System.out.println(files[i]);

  * }

  * </pre>

  *

  * <p>

  * Example, showing how to print out a list of the

  * current directory's <i>read-only</i> files:

  *

  * <pre>

  * File dir = new File(".");

  * String[] files = dir.list( CanReadFileFilter.READ_ONLY );

  * for ( int i = 0; i < files.length; i++ ) {

  *     System.out.println(files[i]);

  * }

  * </pre>

  *

  * @since 1.3

  * @version $Id: CanReadFileFilter.java 1471767 2013-04-24 23:24:19Z sebb $

  */

 public class CanReadFileFilter extends AbstractFileFilter implements Serializable {

     /** Singleton instance of <i>readable</i> filter */

     public static final IOFileFilter CAN_READ = new CanReadFileFilter();

     /** Singleton instance of not <i>readable</i> filter */

     public static final IOFileFilter CANNOT_READ = new NotFileFilter(CAN_READ);

     /** Singleton instance of <i>read-only</i> filter */

     public static final IOFileFilter READ_ONLY = new AndFileFilter(CAN_READ,

                                                 CanWriteFileFilter.CANNOT_WRITE);

     /**

      * Restrictive consructor.

      */

     protected CanReadFileFilter() {

     }

     /**

      * Checks to see if the file can be read.

      *

      * @param file  the File to check.

      * @return {@code true} if the file can be

      *  read, otherwise {@code false}.

      */

     @Override

     public boolean accept(final File file) {

         return file.canRead();

     }

 }