How to get the size of file or directory

How to get the size of file or directory, The size of a directory should be the total size of all contained files? i know the method File.length will return the size of a file (but not of a directory).

for example:
one-a 52
one-b 60
one 112
three-a 24
three 24
two 0
test0 136
ericylrAsked:
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Ajay-SinghCommented:
You can use this recursive function:

  public long size(File file) {
    if (file.isFile())
      return file.length();

    File[] list = file.listFiles();
    if (null == list || list.length == 0)
      return 0;

    long size = 0;
    for (int i = 0; i < list.length; i++)
      size += size(list[i]);

    return size;
  }
0

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Mayank SAssociate Director - Product EngineeringCommented:
Traverse a directory using: http://www.exampledepot.com/egs/java.io/TraverseTree.html

In the method, keep adding the length :)
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ericylrAuthor Commented:
Ajay-Singh:  thank you very much, below is my code:
               if (dir.isDirectory()){
                        File[] list = dir.listFiles();
                   long size=0;
                  for (int i = 0; i < list.length; i++)
                          size += list[i].length();
                  System.out.println(dir.getName() + " " + size);
                }else{
                        long filesize = dir.length();
                  System.out.println(dir.getName() + " " + filesize);
                }         
My testing structure is Directory: test0;  Sub-directory: one,two,three;
C:\>java SizeTest c:\test0
one-a.txt 303
one-b.txt 1087
one-c.txt 0
one 1390
three 0
two-a.txt 1041
two-b.txt 1049
two 1041
test0 0

the output is not correct, the size of Directory Test0 should not be 0
0
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ericylrAuthor Commented:
The question reqiure me edit the afterLast Method to print out the directory and file size, how to use  recursive in the afterLast method?

Below is my code:

public class SizeList extends DirectoryTour{

      public Object afterLast(File dir, Object info) {
                if (dir.isDirectory()){
                        File[] list = dir.listFiles();
                   long size=0;

                  for (int i = 0; i < list.length; i++)
                          size += list[i].length();
                  System.out.println(dir.getName() + " " + size);
                }else{
                        long filesize = dir.length();
                  System.out.println(dir.getName() + " " + filesize);
                }                       
               return info;         
      }


 }
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ericylrAuthor Commented:
anybody can help?
0
Mayank SAssociate Director - Product EngineeringCommented:
Why are you returning an Object info? It is not getting changed anywhere. use the code that Ajay posted - it uses recursion.
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