CharArrayReader

public class CharArrayReader
extends Reader

java.lang.Object
   ↳ java.io.Reader
     ↳ java.io.CharArrayReader


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

Summary

Fields

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 fields

Public constructors

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 methods

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 methods

Fields

buf

Added in API level 1
protected char[] buf

The character buffer.

count

Added in API level 1
protected int count

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

markedPos

Added in API level 1
protected int markedPos

The position of mark in buffer.

pos

Added in API level 1
protected int pos

The current buffer position.

Public constructors

CharArrayReader

Added in API level 1
public CharArrayReader (char[] buf)

Creates a CharArrayReader from the specified array of chars.

Parameters
buf char: Input buffer (not copied)

CharArrayReader

Added in API level 1
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 char: Input buffer (not copied)

offset int: Offset of the first char to read

length int: 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

close

Added in API level 1
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. This method will block while there is another thread blocking on the reader.

mark

Added in API level 1
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 int: 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

markSupported

Added in API level 1
public boolean markSupported ()

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

Returns
boolean true if and only if this stream supports the mark operation.

read

Added in API level 1
public int read ()

Reads a single character.

Returns
int 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

read

Added in API level 1
public int read (char[] b, 
                int off, 
                int len)

Reads characters into a portion of an array.

Parameters
b char: Destination buffer

off int: Offset at which to start storing characters

len int: Maximum number of characters to read

Returns
int 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
IndexOutOfBoundsException

ready

Added in API level 1
public boolean ready ()

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

Returns
boolean 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

reset

Added in API level 1
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

skip

Added in API level 1
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 long: The number of characters to skip

Returns
long The number of characters actually skipped

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