java实现递归文件列表的方法

时间:2021-05-19

本文实例讲述了java实现递归文件列表的方法。分享给大家供大家参考。具体如下:

FileListing.java如下:

import java.util.*;import java.io.*;/*** Recursive file listing under a specified directory.* * @author javapractices.com* @author Alex Wong* @author anonymous user*/public final class FileListing { /** * Demonstrate use. * * @param aArgs - <tt>aArgs[0]</tt> is the full name of an existing * directory that can be read. */ public static void main(String... aArgs) throws FileNotFoundException { File startingDirectory= new File(aArgs[0]); List<File> files = FileListing.getFileListing(startingDirectory); //print out all file names, in the the order of File.compareTo() for(File file : files ){ System.out.println(file); } } /** * Recursively walk a directory tree and return a List of all * Files found; the List is sorted using File.compareTo(). * * @param aStartingDir is a valid directory, which can be read. */ static public List<File> getFileListing( File aStartingDir ) throws FileNotFoundException { validateDirectory(aStartingDir); List<File> result = getFileListingNoSort(aStartingDir); Collections.sort(result); return result; } // PRIVATE // static private List<File> getFileListingNoSort( File aStartingDir ) throws FileNotFoundException { List<File> result = new ArrayList<File>(); File[] filesAndDirs = aStartingDir.listFiles(); List<File> filesDirs = Arrays.asList(filesAndDirs); for(File file : filesDirs) { result.add(file); //always add, even if directory if ( ! file.isFile() ) { //must be a directory //recursive call! List<File> deeperList = getFileListingNoSort(file); result.addAll(deeperList); } } return result; } /** * Directory is valid if it exists, does not represent a file, and can be read. */ static private void validateDirectory ( File aDirectory ) throws FileNotFoundException { if (aDirectory == null) { throw new IllegalArgumentException("Directory should not be null."); } if (!aDirectory.exists()) { throw new FileNotFoundException("Directory does not exist: " + aDirectory); } if (!aDirectory.isDirectory()) { throw new IllegalArgumentException("Is not a directory: " + aDirectory); } if (!aDirectory.canRead()) { throw new IllegalArgumentException("Directory cannot be read: " + aDirectory); } }}

希望本文所述对大家的java程序设计有所帮助。

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