Class BufferedWriter
- All Implemented Interfaces:
Closeable
,Flushable
,Appendable
,AutoCloseable
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,
PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("foo.out")));
- Since:
- 1.1
- See Also:
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Field Summary
-
Constructor Summary
ConstructorDescriptionBufferedWriter
(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. -
Method Summary
Modifier and TypeMethodDescriptionvoid
close()
Closes the stream, flushing it first.void
flush()
Flushes the stream.void
newLine()
Writes a line separator.void
write
(char[] cbuf, int off, int len) Writes a portion of an array of characters.void
write
(int c) Writes a single character.void
Writes a portion of a String.
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Constructor Details
-
BufferedWriter
Creates a buffered character-output stream that uses a default-sized output buffer.- Parameters:
out
- A Writer
-
BufferedWriter
Creates a new buffered character-output stream that uses an output buffer of the given size.- Parameters:
out
- A Writersz
- Output-buffer size, a positive integer- Throws:
IllegalArgumentException
- Ifsz <= 0
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Method Details
-
write
Writes a single character.- Overrides:
write
in classWriter
- Parameters:
c
- int specifying a character to be written- Throws:
IOException
- If an I/O error occurs
-
write
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
BufferedWriter
s will not copy data unnecessarily.- Specified by:
write
in classWriter
- Parameters:
cbuf
- A character arrayoff
- Offset from which to start reading characterslen
- Number of characters to write- Throws:
IndexOutOfBoundsException
- Ifoff
is negative, orlen
is negative, oroff + len
is negative or greater than the length of the given arrayIOException
- If an I/O error occurs
-
write
Writes a portion of a String.- Overrides:
write
in classWriter
- Implementation Requirements:
- While the specification of this method in the
superclass
recommends that an
IndexOutOfBoundsException
be thrown iflen
is negative oroff + len
is negative, the implementation in this class does not throw such an exception in these cases but instead simply writes no characters. - Parameters:
s
- String to be writtenoff
- Offset from which to start reading characterslen
- Number of characters to be written- Throws:
IndexOutOfBoundsException
- Ifoff
is negative, oroff + len
is greater than the length of the given stringIOException
- If an I/O error occurs
-
newLine
Writes a line separator. The line separator string is defined by the system propertyline.separator
, and is not necessarily a single newline ('\n') character.- Throws:
IOException
- If an I/O error occurs
-
flush
Flushes the stream.- Specified by:
flush
in interfaceFlushable
- Specified by:
flush
in classWriter
- Throws:
IOException
- If an I/O error occurs
-
close
Description copied from class:Writer
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.- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceCloseable
- Specified by:
close
in classWriter
- Throws:
IOException
- If an I/O error occurs
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