- 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")));
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.-
Field Summary
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Constructor Summary
ConstructorsConstructorDescriptionBufferedWriter(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 TypeMethodDescriptionvoidclose()Closes the stream, flushing it first.voidflush()Flushes the stream.voidnewLine()Writes a line separator.voidwrite(char[] cbuf, int off, int len) Writes a portion of an array of characters.voidwrite(int c) Writes a single character.voidWrites a portion of a String.
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Constructor Details
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BufferedWriter
Creates a buffered character-output stream that uses a default-sized output buffer.- Parameters:
out- A Writer
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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
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write
Writes a single character.- Overrides:
writein classWriter- Parameters:
c- int specifying a character to be written- Throws:
IOException- If an I/O error occurs
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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
BufferedWriters will not copy data unnecessarily.- Specified by:
writein classWriter- Parameters:
cbuf- A character arrayoff- Offset from which to start reading characterslen- Number of characters to write- Throws:
IndexOutOfBoundsException- Ifoffis negative, orlenis negative, oroff + lenis negative or greater than the length of the given arrayIOException- If an I/O error occurs
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write
Writes a portion of a String.- Overrides:
writein classWriter- Implementation Requirements:
- While the specification of this method in the
superclass
recommends that an
IndexOutOfBoundsExceptionbe thrown iflenis negative oroff + lenis 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- Ifoffis negative, oroff + lenis greater than the length of the given stringIOException- If an I/O error occurs
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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
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flush
Flushes the stream.- Specified by:
flushin interfaceFlushable- Specified by:
flushin classWriter- Throws:
IOException- If an I/O error occurs
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close
Description copied from class:WriterCloses 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:
closein interfaceAutoCloseable- Specified by:
closein interfaceCloseable- Specified by:
closein classWriter- Throws:
IOException- If an I/O error occurs
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