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：
importjava.util.*;
importjava.io.*;
/**
*Recursivefilelistingunderaspecifieddirectory.
*
*@authorjavapractices.com
*@authorAlexWong
*@authoranonymoususer
*/
publicfinalclassFileListing{
/**
*Demonstrateuse.
*
*@paramaArgs-<tt>aArgs[0]</tt>isthefullnameofanexisting
*directorythatcanberead.
*/
publicstaticvoidmain(String...aArgs)throwsFileNotFoundException{
FilestartingDirectory=newFile(aArgs[0]);
List<File>files=FileListing.getFileListing(startingDirectory);
//printoutallfilenames,inthetheorderofFile.compareTo()
for(Filefile:files){
System.out.println(file);
}
}
/**
*RecursivelywalkadirectorytreeandreturnaListofall
*Filesfound;theListissortedusingFile.compareTo().
*
*@paramaStartingDirisavaliddirectory,whichcanberead.
*/
staticpublicList<File>getFileListing(
FileaStartingDir
)throwsFileNotFoundException{
validateDirectory(aStartingDir);
List<File>result=getFileListingNoSort(aStartingDir);
Collections.sort(result);
returnresult;
}
//PRIVATE//
staticprivateList<File>getFileListingNoSort(
FileaStartingDir
)throwsFileNotFoundException{
List<File>result=newArrayList<File>();
File[]filesAndDirs=aStartingDir.listFiles();
List<File>filesDirs=Arrays.asList(filesAndDirs);
for(Filefile:filesDirs){
result.add(file);//alwaysadd,evenifdirectory
if(!file.isFile()){
//mustbeadirectory
//recursivecall!
List<File>deeperList=getFileListingNoSort(file);
result.addAll(deeperList);
}
}
returnresult;
}
/**
*Directoryisvalidifitexists,doesnotrepresentafile,andcanberead.
*/
staticprivatevoidvalidateDirectory(
FileaDirectory
)throwsFileNotFoundException{
if(aDirectory==null){
thrownewIllegalArgumentException("Directoryshouldnotbenull.");
}
if(!aDirectory.exists()){
thrownewFileNotFoundException("Directorydoesnotexist:"+aDirectory);
}
if(!aDirectory.isDirectory()){
thrownewIllegalArgumentException("Isnotadirectory:"+aDirectory);
}
if(!aDirectory.canRead()){
thrownewIllegalArgumentException("Directorycannotberead:"+aDirectory);
}
}
}
希望本文所述对大家的java程序设计有所帮助。