Closeable
, Flushable
, Appendable
, AutoCloseable
public class BufferedWriter extends Writer
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")));
Constructor | Description |
---|---|
BufferedWriter |
Creates a buffered character-output stream that uses a default-sized output buffer. |
BufferedWriter |
Creates a new buffered character-output stream that uses an output buffer of the given size. |
Modifier and Type | Method | Description |
---|---|---|
void |
close() |
Closes the stream, flushing it first. |
void |
flush() |
Flushes the stream. |
void |
newLine() |
Writes a line separator. |
void |
write |
Writes a portion of an array of characters. |
void |
write |
Writes a single character. |
void |
write |
Writes a portion of a String. |
public BufferedWriter(Writer out)
out
- A Writerpublic BufferedWriter(Writer out, int sz)
out
- A Writersz
- Output-buffer size, a positive integerIllegalArgumentException
- If sz <= 0
public void write(int c) throws IOException
write
in class Writer
c
- int specifying a character to be writtenIOException
- If an I/O error occurspublic void write(char[] cbuf, int off, int len) throws IOException
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.
write
in class Writer
cbuf
- A character arrayoff
- Offset from which to start reading characterslen
- Number of characters to writeIndexOutOfBoundsException
- If off
is negative, or len
is negative, or off + len
is negative or greater than the length of the given arrayIOException
- If an I/O error occurspublic void write(String s, int off, int len) throws IOException
write
in class Writer
IndexOutOfBoundsException
be thrown if len
is negative or off + len
is negative, the implementation in this class does not throw such an exception in these cases but instead simply writes no characters.s
- String to be writtenoff
- Offset from which to start reading characterslen
- Number of characters to be writtenIndexOutOfBoundsException
- If off
is negative, or off + len
is greater than the length of the given stringIOException
- If an I/O error occurspublic void newLine() throws IOException
line.separator
, and is not necessarily a single newline ('\n') character.IOException
- If an I/O error occurspublic void flush() throws IOException
flush
in interface Flushable
flush
in class Writer
IOException
- If an I/O error occurspublic void close() throws IOException
Writer
close
in interface AutoCloseable
close
in interface Closeable
close
in class Writer
IOException
- If an I/O error occurs
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/io/BufferedWriter.html