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Class java.io.BufferedWriter
java.lang.Object
|
+----java.io.Writer
|
+----java.io.BufferedWriter
- public class BufferedWriter
- extends Writer
Write 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,
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. - See Also:
- PrintWriter, FileWriter, OutputStreamWriter
- BufferedWriter(Writer)
- Create a buffered character-output stream that uses a default-sized output buffer.
- BufferedWriter(Writer, int)
- Create a new buffered character-output stream that uses an output buffer of the given size.
- close()
- Close the stream.
- flush()
- Flush the stream.
- newLine()
- Write a line separator.
- write(char[], int, int)
- Write a portion of an array of characters.
- write(int)
- Write a single character.
- write(String, int, int)
- Write a portion of a String.
BufferedWriter
public BufferedWriter(Writer out)
- Create a buffered character-output stream that uses a default-sized output buffer.
- Parameters:
- out - A Writer
BufferedWriter
public BufferedWriter(Writer out,
int sz)
- Create a new buffered character-output stream that uses an output buffer of the given size.
- Parameters:
- out - A Writer
- sz - Output-buffer size, a positive integer
- Throws: IllegalArgumentException
- If sz is <= 0
write
public void write(int c) throws IOException
- Write a single character.
- Throws: IOException
- If an I/O error occurs
- Overrides:
- write in class Writer
write
public void write(char cbuf[],
int off,
int len) throws IOException
- Write 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.
- Parameters:
- cbuf - A character array
- off - Offset from which to start reading characters
- len - Number of characters to write
- Throws: IOException
- If an I/O error occurs
- Overrides:
- write in class Writer
write
public void write(String s,
int off,
int len) throws IOException
- Write a portion of a String.
- Parameters:
- s - String to be written
- off - Offset from which to start reading characters
- len - Number of characters to be written
- Throws: IOException
- If an I/O error occurs
- Overrides:
- write in class Writer
newLine
public void newLine() throws IOException
- Write 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
flush
public void flush() throws IOException
- Flush the stream.
- Throws: IOException
- If an I/O error occurs
- Overrides:
- flush in class Writer
close
public void close() throws IOException
- Close the stream.
- Throws: IOException
- If an I/O error occurs
- Overrides:
- close in class Writer
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