Class: java.io.BufferedWriter

  • public class BufferedWriter
  • extends Writer
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, 

 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.
Authors:
@author Mark Reinhold
See:
@see java.io.PrintWriter
@see java.io.FileWriter
@see java.io.OutputStreamWriter
Since:
@since JDK1.1

Inheritance

Superclass tree: Implements:

Methods

  • BufferedWritertop

    public BufferedWriter(Writer out)
    Creates a buffered character-output stream that uses a default-sized output buffer.
    Parameters:
    @param out A Writer
    Related Links:
    Google Code Search
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  • BufferedWritertop

    public BufferedWriter(Writer out, int sz)
    Creates a new buffered character-output stream that uses an output buffer of the given size.
    Parameters:
    @param out A Writer
    @param sz Output-buffer size, a positive integer
    Exceptions:
    @exception IllegalArgumentException If sz is <_ _0="_0" dd="dd">
    Related Links:
    Google Code Search
    Stack Overflow

  • closetop

    public void close() throws IOException
    Closes this stream and releases any system resources associated with it. If the stream is already closed then invoking this method has no effect.
    Exceptions:
    @throws IOException if an I/O error occurs
    Specified by:
    close from Closeable
    Override hierarchy:
    close from Writer
    Related Links:
    Google Code Search
    Stack Overflow

  • flushtop

    public void flush() throws IOException
    Flushes the stream.
    Exceptions:
    @exception IOException If an I/O error occurs
    Specified by:
    flush from Flushable
    Override hierarchy:
    flush from Writer
    Related Links:
    Google Code Search
    Stack Overflow

  • newLinetop

    public void newLine() throws IOException
    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.
    Exceptions:
    @exception IOException If an I/O error occurs
    Related Links:
    Google Code Search
    Stack Overflow

  • writetop

    public void write(int c) throws IOException
    Writes a single character.
    Parameters:
    @param c int specifying a character to be written
    Exceptions:
    @exception IOException If an I/O error occurs
    Override hierarchy:
    write from Writer
    Related Links:
    Google Code Search
    Stack Overflow

  • writetop

    public void write(String s, int off, int len) throws IOException
    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:
    @param s String to be written
    @param off Offset from which to start reading characters
    @param len Number of characters to be written
    Exceptions:
    @exception IOException If an I/O error occurs
    Override hierarchy:
    write from Writer
    Related Links:
    Google Code Search
    Stack Overflow

  • writetop

    public void write(char[] cbuf, int off, int len) throws IOException
    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:
    @param cbuf A character array
    @param off Offset from which to start reading characters
    @param len Number of characters to write
    Exceptions:
    @exception IOException If an I/O error occurs
    Override hierarchy:
    write from Writer
    Related Links:
    Google Code Search
    Stack Overflow