Java Traversal Sub-directory

 PackageCom.imooc.io;ImportJava.io.File;Importjava.io.IOException;//lists some of the common uses of file, such as filtering, traversal, etc. Public classFileUtils {//list all files under the development directory (including their subdirectories)     Public  Static voidListDirectory (File dir)throwsioexception{if(!dir.exists ()) {            Throw NewIllegalArgumentException ("Directory:" +dir+ "does not exist"); }        if(!dir.isdirectory ()) {            Throw NewIllegalArgumentException (dir+ "directory does not exist"); }        //the list () method is used to list subdirectories and files in the current directory//string[] Filenames=dir.list ();//returns the string array, the name of the direct child, without the contents of the subdirectory//For (String string:filenames) {//System.out.println (string);//        }        //if you want to traverse the contents of a subdirectory, you need to construct the file object to do the recursive operation .File[] Files=dir.listfiles ();//returns an abstraction of a direct subdirectory (file)        if(files!=NULL&&files.length>0)        {             for(File file:files) {if(File.isdirectory ()) {//Recursivelistdirectory (file); }Else{System.out.println (file); }            }        }//For (File file:files)//        {//System.out.println (file);//        }    }}

Java Traversal Sub-directory