Two Methods for Traversing folders in Java

A. Do not use recursion:

Import java. Io. file; Import java. util. Collections list; Public class filesystem { Public static void main (string [] ARGs ){ Long A = system. currenttimemillis (); Jsonlist list = new jsonlist (); File dir = new file ("C:" "Java """); File file [] = dir. listfiles (); For (INT I = 0; I <file. length; I ++ ){ If (file [I]. isdirectory ()) List. Add (file [I]); Else System. Out. println (file [I]. getabsolutepath ()); } File TMP; While (! List. isempty ()){ TMP = List. removefirst (); If (TMP. isdirectory ()){ File = TMP. listfiles (); If (file = NULL) Continue; For (INT I = 0; I <file. length; I ++ ){ If (file [I]. isdirectory ()) List. Add (file [I]); Else System. Out. println (file [I]. getabsolutepath ()); } } Else { System. Out. println (TMP. getabsolutepath ()); } } System. Out. println (system. currenttimemillis ()-); } }

B. recursion:

Import Java. io. file; Import Java. util. arraylist; public class filesystem1 { Private Static arraylist filelist = new arraylist (); Public static void main (string [] ARGs) { long a = system. currenttimemillis (); refreshfilelist ("C:" "Java"); system. out. println (system. currenttimemillis ()-A); } Public static void refreshfilelist (string strpath) { file dir = new file (strpath); file [] files = dir. listfiles (); If (Files = NULL) return; for (INT I = 0; I If (files [I]. isdirectory () { refreshfilelist (files [I]. getabsolutepath (); }else { string strfilename = files [I]. getabsolutepath (). tolowercase (); system. out. println ("---" + strfilename); filelist. add (files [I]. getabsolutepath ()); }

conclusion: the Recursive Method B has better performance.