public class LongLineBufferedReader
extends java.io.Reader
BufferedReader with improved performance reading files with long lines.
This class is almost identical to BufferedReader, but it retains a single line buffer for accumulating characters in a line, and allows
its size to grow. Conversely, BufferedReader assumes each new line will be approximately 80 characters and its
performance suffers when that is not the case.
Unlike BufferedReader, this class is not thread safe.| Constructor and Description |
|---|
LongLineBufferedReader(java.io.Reader in)
Creates a buffering character-input stream that uses a default-sized
input buffer.
|
LongLineBufferedReader(java.io.Reader in,
int sz)
Creates a buffering character-input stream that uses an input buffer of
the specified size.
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| Modifier and Type | Method and Description |
|---|---|
void |
close() |
void |
mark(int readAheadLimit)
Marks the present position in the stream.
|
boolean |
markSupported()
Tells whether this stream supports the mark() operation, which it does.
|
int |
read()
Reads a single character.
|
int |
read(char[] cbuf,
int off,
int len)
Reads characters into a portion of an array.
|
java.lang.String |
readLine()
Reads a line of text.
|
boolean |
ready()
Tells whether this stream is ready to be read.
|
void |
reset()
Resets the stream to the most recent mark.
|
long |
skip(long n)
Skips characters.
|
public LongLineBufferedReader(java.io.Reader in,
int sz)
in - A Readersz - Input-buffer sizejava.lang.IllegalArgumentException - If sz is <= 0public LongLineBufferedReader(java.io.Reader in)
in - A Readerpublic int read()
throws java.io.IOException
read in class java.io.Readerjava.io.IOException - If an I/O error occurspublic int read(char[] cbuf,
int off,
int len)
throws java.io.IOException
This method implements the general contract of the corresponding
method of the
read class. As an additional convenience, it
attempts to read as many characters as possible by repeatedly invoking
the Readerread method of the underlying stream. This iterated
read continues until one of the following conditions becomes
true:
read method of the underlying stream returns
-1, indicating end-of-file, or
ready method of the underlying stream
returns false, indicating that further input requests
would block.
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 BufferedReaderTwos will not copy data
unnecessarily.
read in class java.io.Readercbuf - Destination bufferoff - Offset at which to start storing characterslen - Maximum number of characters to readjava.io.IOException - If an I/O error occurspublic java.lang.String readLine()
throws java.io.IOException
java.io.IOException - If an I/O error occurspublic long skip(long n)
throws java.io.IOException
skip in class java.io.Readern - The number of characters to skipjava.lang.IllegalArgumentException - If n is negative.java.io.IOException - If an I/O error occurspublic boolean ready()
throws java.io.IOException
ready in class java.io.Readerjava.io.IOException - If an I/O error occurspublic boolean markSupported()
markSupported in class java.io.Readerpublic void mark(int readAheadLimit)
throws java.io.IOException
mark in class java.io.ReaderreadAheadLimit - Limit on the number of characters that may be
read while still preserving the mark. An attempt
to reset the stream after reading characters
up to this limit or beyond may fail.
A limit value larger than the size of the input
buffer will cause a new buffer to be allocated
whose size is no smaller than limit.
Therefore large values should be used with care.java.lang.IllegalArgumentException - If readAheadLimit is < 0java.io.IOException - If an I/O error occurspublic void reset()
throws java.io.IOException
reset in class java.io.Readerjava.io.IOException - If the stream has never been marked,
or if the mark has been invalidatedpublic void close()
throws java.io.IOException
close in interface java.io.Closeableclose in interface java.lang.AutoCloseableclose in class java.io.Readerjava.io.IOException