| java.lang.Object
 java.io.Reader
java.io.BufferedReader
All known Subclasses: java.io.LineNumberReader,
| BufferedReader | | public class BufferedReader extends Reader (Code) | | Reads text from a character-input stream, buffering characters so as to
provide for the efficient reading of characters, arrays, and lines.
The buffer size may be specified, or the default size may be used. The
default is large enough for most purposes.
In general, each read request made of a Reader causes a corresponding
read request to be made of the underlying character or byte stream. It is
therefore advisable to wrap a BufferedReader around any Reader whose read()
operations may be costly, such as FileReaders and InputStreamReaders. For
example,
BufferedReader in
= new BufferedReader(new FileReader("foo.in"));
will buffer the input from the specified file. Without buffering, each
invocation of read() or readLine() could cause bytes to be read from the
file, converted into characters, and then returned, which can be very
inefficient.
Programs that use DataInputStreams for textual input can be localized by
replacing each DataInputStream with an appropriate BufferedReader.
See Also: FileReader
See Also: InputStreamReader
version:
1.43, 07/05/05
author:
Mark Reinhold
since:
JDK1.1 |
| Constructor Summary | |
| public | BufferedReader(Reader in, int sz)
Creates a buffering character-input stream that uses an input buffer of
the specified size. | | public | BufferedReader(Reader in)
Creates a buffering character-input stream that uses a default-sized
input buffer. |
| Method Summary | |
| public void | close()
| | public void | mark(int readAheadLimit)
Marks the present position in the stream. | | public boolean | markSupported()
Tells whether this stream supports the mark() operation, which it does. | | public int | read()
Reads a single character. | | public int | read(char cbuf, int off, int len)
Reads characters into a portion of an array.
This method implements the general contract of the corresponding
Reader.read(char[]intint) read method of the
Reader class. | | String | readLine(boolean ignoreLF)
Reads a line of text. | | public String | readLine()
Reads a line of text. | | public boolean | ready()
Tells whether this stream is ready to be read. | | public void | reset()
Resets the stream to the most recent mark. | | public long | skip(long n)
Skips characters. |
| BufferedReader | | public BufferedReader(Reader in, int sz)(Code) | | Creates a buffering character-input stream that uses an input buffer of
the specified size.
Parameters:
in - A Reader
Parameters:
sz - Input-buffer size
exception:
IllegalArgumentException - If sz is <= 0 |
| BufferedReader | | public BufferedReader(Reader in)(Code) | | Creates a buffering character-input stream that uses a default-sized
input buffer.
Parameters:
in - A Reader |
| mark | | public void mark(int readAheadLimit) throws IOException(Code) | | Marks the present position in the stream. Subsequent calls to reset()
will attempt to reposition the stream to this point.
Parameters:
readAheadLimit - Limit on the number of characters that may beread while still preserving the mark. An attemptto reset the stream after reading charactersup to this limit or beyond may fail.A limit value larger than the size of the inputbuffer will cause a new buffer to be allocatedwhose size is no smaller than limit.Therefore large values should be used with care.
exception:
IllegalArgumentException - If readAheadLimit is < 0
exception:
IOException - If an I/O error occurs |
| markSupported | | public boolean markSupported()(Code) | | Tells whether this stream supports the mark() operation, which it does.
|
| read | | public int read() throws IOException(Code) | | Reads a single character.
The character read, as an integer in the range0 to 65535 (0x00-0xffff), or -1 if theend of the stream has been reached
exception:
IOException - If an I/O error occurs |
| read | | public int read(char cbuf, int off, int len) throws IOException(Code) | | Reads characters into a portion of an array.
This method implements the general contract of the corresponding
Reader.read(char[]intint) read method of the
Reader class. As an additional convenience, it
attempts to read as many characters as possible by repeatedly invoking
the read method of the underlying stream. This iterated
read continues until one of the following conditions becomes
true:
- The specified number of characters have been read,
- The
read method of the underlying stream returns
-1, indicating end-of-file, or
- The
ready method of the underlying stream
returns false, indicating that further input requests
would block.
If the first read on the underlying stream returns
-1 to indicate end-of-file then this method returns
-1. Otherwise this method returns the number of characters
actually read.
Subclasses of this class are encouraged, but not required, to
attempt to read as many characters as possible in the same fashion.
Ordinarily this method takes characters from this stream's character
buffer, filling it from the underlying stream as necessary. If,
however, the buffer is empty, the mark is not valid, and the requested
length is at least as large as the buffer, then this method will read
characters directly from the underlying stream into the given array.
Thus redundant BufferedReaders will not copy data
unnecessarily.
Parameters:
cbuf - Destination buffer
Parameters:
off - Offset at which to start storing characters
Parameters:
len - Maximum number of characters to read The number of characters read, or -1 if the end of thestream has been reached
exception:
IOException - If an I/O error occurs |
| readLine | | String readLine(boolean ignoreLF) throws IOException(Code) | | Reads a line of text. A line is considered to be terminated by any one
of a line feed ('\n'), a carriage return ('\r'), or a carriage return
followed immediately by a linefeed.
Parameters:
ignoreLF - If true, the next '\n' will be skipped A String containing the contents of the line, not includingany line-termination characters, or null if the end of thestream has been reached
See Also: java.io.LineNumberReader.readLine
exception:
IOException - If an I/O error occurs |
| readLine | | public String readLine() throws IOException(Code) | | Reads a line of text. A line is considered to be terminated by any one
of a line feed ('\n'), a carriage return ('\r'), or a carriage return
followed immediately by a linefeed.
A String containing the contents of the line, not includingany line-termination characters, or null if the end of thestream has been reached
exception:
IOException - If an I/O error occurs |
| ready | | public boolean ready() throws IOException(Code) | | Tells whether this stream is ready to be read. A buffered character
stream is ready if the buffer is not empty, or if the underlying
character stream is ready.
exception:
IOException - If an I/O error occurs |
| reset | | public void reset() throws IOException(Code) | | Resets the stream to the most recent mark.
exception:
IOException - If the stream has never been marked,or if the mark has been invalidated |
| skip | | public long skip(long n) throws IOException(Code) | | Skips characters.
Parameters:
n - The number of characters to skip The number of characters actually skipped
exception:
IllegalArgumentException - If n is negative.
exception:
IOException - If an I/O error occurs |
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