Java Reference
In-Depth Information
InputStream
subclasses such as
ByteArrayInputStream
support marking
thecurrentreadpositionintheinputstreamviathe
mark()
method,andlaterreturnto
that position via the
reset()
method.
Caution
Don'tforgettocall
markSupported()
tofindoutifthestreamsubclass
supports
mark()
and
reset()
.
FileOutputStream and FileInputStream
Files are common stream destinations and sources. The concrete
FileOut-
putStream
class lets you write a stream of bytes to a file; the concrete
FileIn-
putStream
class lets you read a stream of bytes from a file.
FileOutputStream
subclasses
OutputStream
and declares five constructors
for creating file output streams. For example,
FileOutputStream(String
name)
creates a file output stream to the existing file identified by
name
. This con-
structorthrows
FileNotFoundException
whenthefiledoesn'texistandcannotbe
created,itisadirectoryratherthananormalfile,orthefilecannotbeotherwiseopened
for output.
The following example uses
FileOutputStream(String name)
to create a
file output stream with
employee.dat
as its destination:
FileOutputStream
fos
=
new
FileOut-
putStream("employee.dat");
Tip
FileOutputStream(String name)
overwrites an existing file. To ap-
pend data instead of overwriting existing content, call a
FileOutputStream
con-
structorthatincludesa
boolean append
parameterandpass
true
tothisparamet-
er.
