com.peterphi.std.io

Class CharSequenceReader

java.lang.Object

java.io.Reader

com.peterphi.std.io.CharSequenceReader

All Implemented Interfaces:

Closeable, AutoCloseable, Readable

public class CharSequenceReader
extends Reader

A Reader whose source is a CharSequence (such as a StringBuilder or a StringBuffer).
This is slightly faster than new StringReader(str.toString()) although it creates a greater number of (small) garbage objects
Implementation based on that of StringReader

Field Summary

Fields inherited from class java.io.Reader

lock

Constructor Summary

Constructors

Constructor and Description
CharSequenceReader(CharSequence str)

Method Summary

Modifier and Type	Method and Description
void	close() Closes the stream and releases any system resources associated with it.
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.
boolean	ready() Tells whether this stream is ready to be read.
void	reset() Resets the stream to the most recent mark, or to the beginning of the string if it has never been marked.
long	skip(long ns) Skips the specified number of characters in the stream.

Methods inherited from class java.io.Reader

read, read

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CharSequenceReader

public CharSequenceReader(CharSequence str)

Method Detail

read

public int read()
         throws IOException

Reads a single character.

Overrides:

read in class Reader

Returns:

The character read, or -1 if the end of the stream has been reached

Throws:

IOException - If an I/O error occurs

read

public int read(char[] cbuf,
                int off,
                int len)
         throws IOException

Reads characters into a portion of an array.

Specified by:

read in class Reader

Parameters:

cbuf - Destination buffer

off - Offset at which to start writing characters

len - Maximum number of characters to read

Returns:

The number of characters read, or -1 if the end of the stream has been reached

Throws:

IOException - If an I/O error occurs

skip

public long skip(long ns)
          throws IOException

Skips the specified number of characters in the stream. Returns the number of characters that were skipped.

The ns parameter may be negative, even though the skip method of the Reader superclass throws an exception in this case. Negative values of ns cause the stream to skip backwards. Negative return values indicate a skip backwards. It is not possible to skip backwards past the beginning of the string.

If the entire string has been read or skipped, then this method has no effect and always returns 0.

Overrides:

skip in class Reader

Throws:

IOException - If an I/O error occurs

ready

public boolean ready()
              throws IOException

Tells whether this stream is ready to be read.

Overrides:

ready in class Reader

Returns:

True if the next read() is guaranteed not to block for input

Throws:

IOException - If the stream is closed

markSupported

public boolean markSupported()

Tells whether this stream supports the mark() operation, which it does.

Overrides:

markSupported in class Reader

mark

public void mark(int readAheadLimit)
          throws IOException

Marks the present position in the stream. Subsequent calls to reset() will reposition the stream to this point.

Overrides:

mark in class Reader

Parameters:

readAheadLimit - Limit on the number of characters that may be read while still preserving the mark. Because the stream's input comes from a string, there is no actual limit, so this argument must not be negative, but is otherwise ignored.

Throws:

IllegalArgumentException - If readAheadLimit is < 0

IOException - If an I/O error occurs

reset

public void reset()
           throws IOException

Resets the stream to the most recent mark, or to the beginning of the string if it has never been marked.

Overrides:

reset in class Reader

Throws:

IOException - If an I/O error occurs

close

public void close()

Closes the stream and releases any system resources associated with it. Once the stream has been closed, further read(), ready(), mark(), or reset() invocations will throw an IOException. Closing a previously closed stream has no effect.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in class Reader