java实现递归文件列表的方法

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。