In this example, the program will traverse the given directory and print out all the directories and files absolute path and name one by one.
Example
package com.mkyong.io;
import java.io.File;
public class DisplayDirectoryAndFile{
public static void main (String args[]) {
displayIt(new File("C:\\Downloads"));
}
public static void displayIt(File node){
System.out.println(node.getAbsoluteFile());
if(node.isDirectory()){
String[] subNote = node.list();
for(String filename : subNote){
displayIt(new File(node, filename));
}
}
}
}
Output
C:\Downloads
C:\Downloads\100 Java Tips.pdf
C:\Downloads\1590599799.rar
C:\Downloads\2009
C:\Downloads\573440.flv
C:\Downloads\575492.flv
C:\Downloads\avira_antivir_personal_en.exe
C:\Downloads\backup-mkyong.com-12-24-2009.tar.gz
......
if (subNote != null) {
for (String filename : subNote) {<—– null exception
displayIt(new File(node, filename));
}
}
Thanks a lot
wow. this is pretty straight-forward. I panicked after seeing this question for the first time. Thanks MKYong.
Hi Mkyong,
your code threw a NullPointerException at least on Windows Vista if a File/Directory is a Symbolic Link
for example:
“C:UsersnixArtDocumentsMy Videos” ,which actually points on my HD to
“C:UsersnixArtVideos”
so now a new question arose: how would you detect & handle symbolic links here?
regardless, great work on your entire site!!!
– nik
hi,
i have the structure like below
src
packagename1
com.one.two
testpackage3
there are three package names in src like i listed above
i want to get the package names from src folder irrespective their structure.
Hey Mkyong,
you are great. Please help me with the following problem:
There are about 15 folders that I have. Every folder has a similar sub structure. I was to merge the contents of the folders:
1. taking 2 folders at a time
2. taking 3 folders at a time
Such that both files with same name are saved.
Example:
folder 1
—pqr
——abc.txt
——xyz.txt
folder 2
—pqr
——abc.txt
after merging:
folder 3
—pqr
——-abc.txt
——-abc.txt(2)
——-xyz.txt
please help me with a java code.
Dear Sir,
i have an application that reads files from folder. Files can be multiple.And another application continusily writes the files to that folder. I want to read files one by one. But my application only reads the latest file at one time i dnt want this plzzz help…
rgs,
sanjay
/* Code for comparing two folder structure for there differences */
package com.ex;
import java.io.File;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
public class JCompare {
static Set S1, S2;
static File f1 = new File(“C:\\Users\\ravi2307\\Downloads”);
static File f2 = new File(“C:\\Users\\ravi2307\\sdd”);
public static void main(String args[]) {
S1 = new HashSet();
S2 = new HashSet();
compare(f1, f2);
}
public static void compare(File f1, File f2) {
displayIt(f1, S1);
displayIt(f2, S2);
String temp = null;
System.out.println(“\n\n\n=============DIFFERENCES===============”);
Iterator itr = S2.iterator();
while (itr.hasNext()) {
temp = itr.next();
if (!S1.contains(temp)) {
System.out.println(“Folder1: “+temp);
}
}
Iterator itr1 = S1.iterator();
while (itr1.hasNext()) {
temp = itr1.next();
if (!S2.contains(temp)) {
System.out.println(“Folder2: “+temp);
}
}
}
public static void displayIt(File node, Set s1) {
if (node.getAbsoluteFile().toString()
.contains(f1.getAbsolutePath().toString()))
s1.add(node.getAbsoluteFile().toString()
.replace(f1.getAbsolutePath().toString(), “”));
else {
s1.add(node.getAbsoluteFile().toString()
.replace(f2.getAbsolutePath().toString(), “”));
}
System.out.println(node.getAbsoluteFile().toString());
if (node.isDirectory()) {
String[] subNote = node.list();
for (String filename : subNote) {
displayIt(new File(node, filename), s1);
}
}
}
}
Awesome example MKYong… thanks for saving me some time! (^-^)
The following example shows printing directory hierarchy as a TREE just like DOS tree command.
http://bethecoder.com/applications/tutorials/showTutorials.action?tutorialId=Java_Core_General_FileMap
Good luck