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 Detail |
private String lineSeparator
Constructor Detail |
public BufferedWriter(Writer out)
out
- A Writerpublic BufferedWriter(Writer out, int sz)
out
- A Writersz
- Output-buffer size, a positive integerIllegalArgumentException
- If sz is <= 0
Method Detail |
private void ensureOpen()
void flushBuffer()
public void write(int c)
IOException
- If an I/O error occursprivate int min(int a, int b)
public void write(char[] cbuf, int off, int len)
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.
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)
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()
IOException
- If an I/O error occurspublic void flush()
IOException
- If an I/O error occurspublic void close()
IOException
- If an I/O error occurs