Java Reference
In-Depth Information
// Ensure that a filename (or something) was given in argv[0]
iif
(
argv
.
length
==
0
) {
System
.
err
.
println
(
"Usage: Creat filename"
);
System
.
exit
(
1
);
}
for
for
(
String a
:
argv
) {
// Constructing a File object doesn't affect the disk, but
// the createNewFile() method does.
new
new
File
(
a
).
createNewFile
();
}
}
}
Renaming a File
Problem
You need to change a file's name on disk.
Solution
Use a
java.io.File
object's
renameTo()
method.
Discussion
For reasons best left to the gods of Java, the
renameTo()
method requires not the name you
want the file renamed to, but another
File
object referring to the new name. So to rename a
file you must create two
File
objects, one for the existing name and another for the new
name. Then call the
renameTo
method of the existing name's
File
object, passing in the
second
File
object. This is easier to see than to explain, so here goes:
public
public class
class
Rename
Rename
{
public
public static
static
void
void
main
(
String
[]
argv
)
throws
throws
IOException
{
// Construct the file object. Does NOT create a file on disk!
File f
=
new
new
File
(
"Rename.java~"
);
// backup of this source file.
