File Class

[Steven Wong]

Hi,
I'm a bit confused over the methods of the File class: getAbsolutePath, getCanonicalPath, getPath.
What's the difference to the 3 above?
Hope someone could help me out.
Thanks.

[Jamal Hasanov]

A quote from Khalid Mugal's book
(Chapter 18-Files&Streams,page 552)
For example, if the File object represented the absolute pathname "c:\book\ chapter1" on Windows, then this pathname would be returned by these methods.On the other hand, if the File object represented the relative pathname "..\book\chapter1" and the current directory had the absolute pathname "c:\documents", the pathname returned by the getPath(), getAbsolutePath() and getCanonicalPath() methods would be "..\book\chapter1", "c:\documents\..\book\chapter1" and "c:\book\chapter1", respectively.
BTW, you can download this chapter in PDF.
That's all.
Jamal

[Neelima Rao]

getAbsolutePath returns the absolute i,e not relative path of the file or directory.
For example, the following code creates a file
'test' in the directory directly above the
current directory which is C:\java\io
File f1 = new File("..", "test.txt")
f1.createNewFile();
System.out.println( f1.getAbsolutePath() );
Output:
C:\java\io\..\test
the canonical path is the same as the absolute path BUT all relative indicators . and .. are resolved
For example,
System.out.println( f1.getCanonicalPath() );
Output:
// '..' in absolute path is resolved
C:\java\test
getPath converts the abstract pathname into a pathname string.
For example,
System.out.println( f1.getPath() );
Output:
..\test
Hope this helps......

[Steven Wong]

Thanks a lot, guys.

[Manish Hatwalne]

In short, remember this -
1) getPath() returns whatever was passed to the onstructor.
2) getAbsolutePath() returns the current working directory path + whatever was passed to the constructor, as if it is just a plain string concatenation.
3)getCanonicalPath() works similar to getAbsolutePath() but it resolves . to current directory and .. to parent directory, and return the resulting path, much similar to the way relative URLs get resolved to absolute URLs.
HTH,
- Manish