java.lang.Object java.io.Writer java.io.BufferedWriter
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.
Field Summary |
---|
Fields inherited from class java.io. Writer |
---|
lock |
Constructor Summary | |
---|---|
BufferedWriter
(
Writer
out) Create a buffered character-output stream that uses a default-sized output buffer. |
|
BufferedWriter
(
Writer
out, int sz) Create a new buffered character-output stream that uses an output buffer of the given size. |
Method Summary | |
---|---|
void |
close
() Close the stream. |
void |
flush
() Flush the stream. |
void |
newLine
() Write a line separator. |
void |
write
(char[] cbuf, int off, int len) Write a portion of an array of characters. |
void |
write
(int c) Write a single character. |
void |
write
(
String
s, int off, int len) Write a portion of a String. |
Methods inherited from class java.io. Writer |
---|
append , append , write , write |
Methods inherited from class java.lang. Object |
---|
clone , equals , finalize , getClass , hashCode , notify , notifyAll , toString , wait , wait , wait |
Constructor Detail |
---|
public BufferedWriter(Writer out)
public BufferedWriter(Writer out, int sz)
Method Detail |
---|
public void write(int c) throws IOException
public 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 BufferedWriters will not copy data unnecessarily.
public void write(String s, int off, int len) throws IOException
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.
public void newLine() throws IOException
public void flush() throws IOException
public void close() throws IOException