Java Reference
In-Depth Information
The following example writes a character stream to a file using the
FileWriter
class and
the
write(
int
)
method:
FileWriter letters = new FileWriter(“alphabet.txt”);
for (int i = 65; i < 91; i++)
letters.write( (char)i );
letters.close();
The
close()
method is used to close the stream after all characters have been sent to the
destination file. The following is the
alphabet.txt
file produced by this code:
ABCDEFGHIJKLMNOPQRSTUVWXYZ
The
BufferedWriter
class can be used to write a buffered character stream. This class's
objects are created with the
BufferedWriter(
Writer
)
or
BufferedWriter(
Writer
,
int
)
constructors. The
Writer
argument can be any of the character output stream
classes, such as
FileWriter
. The optional second argument is an integer indicating the
size of the buffer to use.
BufferedWriter
has the same three output methods as
FileWriter
:
write(
int
)
,
write(
char[]
,
int
,
int
)
, and
write(
String
,
int
,
int
)
.
Another useful output method is
newLine()
, which sends the preferred end-of-line char-
acter (or characters) for the platform being used to run the program.
The different end-of-line markers can create conversion hassles
when transferring files from one operating system to another, such
as when a Windows XP user uploads a file to a web server that's
running the Linux operating system. Using
newLine()
instead of a
literal (such as
'\n'
) makes your program more user-friendly
across different platforms.
TIP
The
close()
method is called to close the buffered character stream and make sure that
all buffered data is sent to the stream's destination.
In all the examples thus far, a string has been used to refer to the file that's involved in a
stream operation. This often is sufficient for a program that uses files and streams, but if
you want to copy files, rename files, or handle other tasks, a
File
object can be used.
