CharArrayReader

AI-generated Key Takeaways

• CharArrayReader implements a character buffer that can be used as a character-input stream.

• It provides methods for reading characters from a character array, marking and resetting the stream, skipping characters, and closing the stream.

• Two constructors are available: one that takes a character array as input and another that takes a character array along with offset and length for reading a portion of the array.

• CharArrayReader extends the Reader class and inherits its functionality.

• The ready method always returns true because CharArrayReader is always ready to be read.

public class CharArrayReader extends Reader

This class implements a character buffer that can be used as a character-input stream.

Field Summary

protected char[]	buf	The character buffer.
protected int	count	The index of the end of this buffer.
protected int	markedPos	The position of mark in buffer.
protected int	pos	The current buffer position.

Inherited Field Summary

From class java.io.Reader

protected Object

lock

The object used to synchronize operations on this stream.

Public Constructor Summary

	CharArrayReader(char[] buf) Creates a CharArrayReader from the specified array of chars.
	CharArrayReader(char[] buf, int offset, int length) Creates a CharArrayReader from the specified array of chars.

Public Method Summary

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[] b, 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 if it has never been marked.
long	skip(long n) Skips characters.

Inherited Method Summary

From class java.io.Reader

abstract 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.
int	read() Reads a single character.
abstract int	read(char[] cbuf, int off, int len) Reads characters into a portion of an array.
int	read(char[] cbuf) Reads characters into an array.
int	read(CharBuffer target) Attempts to read characters into the specified character buffer.
boolean	ready() Tells whether this stream is ready to be read.
void	reset() Resets the stream.
long	skip(long n) Skips characters.

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

From interface java.lang.Readable

abstract int

read(CharBuffer cb) Attempts to read characters into the specified character buffer.

From interface java.io.Closeable

abstract void

close() Closes this stream and releases any system resources associated with it.

From interface java.lang.AutoCloseable

abstract void

close() Closes this resource, relinquishing any underlying resources.

Fields

protected char[] buf

The character buffer.

protected int count

The index of the end of this buffer. There is not valid data at or beyond this index.

protected int markedPos

The position of mark in buffer.

protected int pos

The current buffer position.

Public Constructors

public CharArrayReader (char[] buf)

Creates a CharArrayReader from the specified array of chars.

Parameters

buf	Input buffer (not copied)

public CharArrayReader (char[] buf, int offset, int length)

Creates a CharArrayReader from the specified array of chars.

The resulting reader will start reading at the given offset. The total number of char values that can be read from this reader will be either length or buf.length-offset, whichever is smaller.

Parameters

buf	Input buffer (not copied)
offset	Offset of the first char to read
length	Number of chars to read

Throws

IllegalArgumentException	If offset is negative or greater than buf.length, or if length is negative, or if the sum of these two values is negative.

Public Methods

public void close ()

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

public void mark (int readAheadLimit)

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

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 character array, there is no actual limit; hence this argument is ignored.

Throws

IOException	If an I/O error occurs

public boolean markSupported ()

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

Returns

• true if and only if this stream supports the mark operation.

public int read ()

Reads a single character.

Returns

• The character read, as an integer in the range 0 to 65535 (0x00-0xffff), or -1 if the end of the stream has been reached

Throws

IOException	If an I/O error occurs

public int read (char[] b, int off, int len)

Reads characters into a portion of an array.

Parameters

b	Destination buffer
off	Offset at which to start storing characters
len	Maximum number of characters to read

Returns

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

Throws

IOException	If an I/O error occurs

public boolean ready ()

Tells whether this stream is ready to be read. Character-array readers are always ready to be read.

Returns

• True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.

Throws

IOException	If an I/O error occurs

public void reset ()

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

Throws

IOException	If an I/O error occurs

public long skip (long n)

Skips characters. Returns the number of characters that were skipped.

The n parameter may be negative, even though the skip method of the Reader superclass throws an exception in this case. If n is negative, then this method does nothing and returns 0.

Parameters

n	The number of characters to skip

Returns

• The number of characters actually skipped

Throws

IOException	If the stream is closed, or an I/O error occurs