public
class
BufferedWriter
extends Writer
| java.lang.Object | ||
| ↳ | java.io.Writer | |
| ↳ | java.io.BufferedWriter | |
Writes text to a character-output stream, buffering characters so as to provide for the efficient writing of single characters, arrays, and strings.
The buffer size may be specified, or the default size may be accepted. The default is large enough for most purposes.
A newLine() method is provided, which uses the platform's own notion of line separator as defined by the system property line.separator. Not all platforms use the newline character ('\n') to terminate lines. Calling this method to terminate each output line is therefore preferred to writing a newline character directly.
In general, a Writer sends its output immediately to the underlying character or byte stream. Unless prompt output is required, it is advisable to wrap a BufferedWriter around any Writer whose write() operations may be costly, such as FileWriters and OutputStreamWriters. For example,
Developers
PrintWriter out
= new PrintWriter(new BufferedWriter(new FileWriter("foo.out")));
will buffer the PrintWriter's output to the file. Without buffering, each
invocation of a print() method would cause characters to be converted into
bytes that would then be written immediately to the file, which can be very
inefficient.
Inherited fields |
|---|
 From
class
java.io.Writer
|
Public constructors | |
|---|---|
BufferedWriter(Writer out)
Creates a buffered character-output stream that uses a default-sized output buffer. |
|
BufferedWriter(Writer out, int sz)
Creates a new buffered character-output stream that uses an output buffer of the given size. |
|
Public methods | |
|---|---|
void
|
close()
Closes the stream, flushing it first. |
void
|
flush()
Flushes the stream. |
void
|
newLine()
Writes a line separator. |
void
|
write(int c)
Writes a single character. |
void
|
write(String s, int off, int len)
Writes a portion of a String. |
void
|
write(char[] cbuf, int off, int len)
Writes a portion of an array of characters. |
Inherited methods | |
|---|---|
From
class
java.io.Writer
| |
From
class
java.lang.Object
| |
From
interface
java.lang.Appendable
| |
From
interface
java.io.Closeable
| |
From
interface
java.io.Flushable
| |
From
interface
java.lang.AutoCloseable
| |
BufferedWriter (Writer out)
Creates a buffered character-output stream that uses a default-sized output buffer.
| Parameters | |
|---|---|
out |
Writer:
A Writer
|
BufferedWriter (Writer out, int sz)
Creates a new buffered character-output stream that uses an output buffer of the given size.
| Parameters | |
|---|---|
out |
Writer:
A Writer |
sz |
int:
Output-buffer size, a positive integer |
| Throws | |
|---|---|
IllegalArgumentException |
If sz is <= 0 |
void close ()
Closes the stream, flushing it first. Once the stream has been closed, further write() or flush() invocations will cause an IOException to be thrown. Closing a previously closed stream has no effect.
| Throws | |
|---|---|
IOException |
|
void flush ()
Flushes the stream.
| Throws | |
|---|---|
IOException |
If an I/O error occurs |
void newLine ()
Writes a line separator. The line separator string is defined by the system property line.separator, and is not necessarily a single newline ('\n') character.
| Throws | |
|---|---|
IOException |
If an I/O error occurs |
void write (int c)
Writes a single character.
| Parameters | |
|---|---|
c |
int:
int specifying a character to be written |
| Throws | |
|---|---|
IOException |
If an I/O error occurs |
void write (String s, int off, int len)
Writes a portion of a String.
If the value of the len parameter is negative then no
characters are written. This is contrary to the specification of this
method in the superclass, which requires that an IndexOutOfBoundsException be
thrown.
| Parameters | |
|---|---|
s |
String:
String to be written |
off |
int:
Offset from which to start reading characters |
len |
int:
Number of characters to be written |
| Throws | |
|---|---|
IOException |
If an I/O error occurs |
void write (char[] cbuf,
int off,
int len)
Writes a portion of an array of characters.
Ordinarily this method stores characters from the given array into
this stream's buffer, flushing the buffer to the underlying stream as
needed. If the requested length is at least as large as the buffer,
however, then this method will flush the buffer and write the characters
directly to the underlying stream. Thus redundant
BufferedWriters will not copy data unnecessarily.
| Parameters | |
|---|---|
cbuf |
char:
A character array |
off |
int:
Offset from which to start reading characters |
len |
int:
Number of characters to write |
| Throws | |
|---|---|
IOException |
If an I/O error occurs |