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.PrintWriter, FileWriter, OutputStreamWriter, Files.newBufferedWriter(java.nio.file.Path, java.nio.charset.Charset, java.nio.file.OpenOption...)
lock public BufferedWriter(Writer out)
Creates a buffered character-output stream that uses a default-sized output buffer.
out - A Writerpublic BufferedWriter(Writer out,
int sz) Creates a new buffered character-output stream that uses an output buffer of the given size.
out - A Writersz - Output-buffer size, a positive integerIllegalArgumentException - If sz <= 0
public void write(int c)
throws IOException Writes a single character.
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 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.
write in class Writer
cbuf - A character arrayoff - Offset from which to start reading characterslen - Number of characters to writeIOException - If an I/O error occurspublic 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.
write in class Writer
s - String to be writtenoff - Offset from which to start reading characterslen - Number of characters to be writtenIOException - If an I/O error occurspublic 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.
IOException - If an I/O error occurspublic void flush()
throws IOException Flushes the stream.
flush in interface Flushable
flush in class Writer
IOException - If an I/O error occurspublic void close()
throws IOException 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.
close in interface Closeable
close in interface AutoCloseable
close in class Writer
IOException - If an I/O error occurs
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Documentation extracted from Debian's OpenJDK Development Kit package.
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