CharArrayReader

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

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

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