CharArrayReader (Java 2 Platform SE 5.0) (original) (raw)

java.io

Class CharArrayReader

java.lang.Object extended by java.io.Reader java.io.CharArrayReader

All Implemented Interfaces:

Closeable, Readable

public class CharArrayReader

extends Reader

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

Since:

JDK1.1

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.

Fields inherited from class java.io.Reader
lock

Constructor Summary
CharArrayReader(char[] buf) Create an CharArrayReader from the specified array of chars.
[CharArrayReader](../../java/io/CharArrayReader.html#CharArrayReader%28char[], int, int%29)(char[] buf, int offset, int length) Create an CharArrayReader from the specified array of chars.

Method Summary
void	close() Close the stream.
void	mark(int readAheadLimit) Mark the present position in the stream.
boolean	markSupported() Tell whether this stream supports the mark() operation, which it does.
int	read() Read a single character.
int	[read](../../java/io/CharArrayReader.html#read%28char[], int, int%29)(char[] b, int off, int len) Read characters into a portion of an array.
boolean	ready() Tell whether this stream is ready to be read.
void	reset() Reset the stream to the most recent mark, or to the beginning if it has never been marked.
long	skip(long n) Skip characters.

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](../../java/lang/Object.html#wait%28long, int%29)

Field Detail

buf

protected char[] buf

The character buffer.

pos

protected int pos

The current buffer position.

markedPos

protected int markedPos

The position of mark in buffer.

count

protected int count

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

Constructor Detail

CharArrayReader

public CharArrayReader(char[] buf)

Create an CharArrayReader from the specified array of chars.

Parameters:

buf - Input buffer (not copied)

CharArrayReader

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

Create an CharArrayReader from the specified array of chars.

The resulting reader will start reading at the givenoffset. The total number of char values that can be read from this reader will be either length orbuf.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](../../java/lang/IllegalArgumentException.html "class in java.lang") - If offset is negative or greater thanbuf.length, or if length is negative, or if the sum of these two values is negative.

Method Detail

read

public int read() throws IOException

Read a single character.

Overrides:

[read](../../java/io/Reader.html#read%28%29) in class [Reader](../../java/io/Reader.html "class in java.io")

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](../../java/io/IOException.html "class in java.io") - If an I/O error occurs

read

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

Read characters into a portion of an array.

Specified by:

[read](../../java/io/Reader.html#read%28char[], int, int%29) in class [Reader](../../java/io/Reader.html "class in java.io")

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](../../java/io/IOException.html "class in java.io") - If an I/O error occurs

skip

public long skip(long n) throws IOException

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

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

Overrides:

[skip](../../java/io/Reader.html#skip%28long%29) in class [Reader](../../java/io/Reader.html "class in java.io")

Parameters:

n - The number of characters to skip

Returns:

The number of characters actually skipped

Throws:

[IOException](../../java/io/IOException.html "class in java.io") - If the stream is closed, or an I/O error occurs

ready

public boolean ready() throws IOException

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

Overrides:

[ready](../../java/io/Reader.html#ready%28%29) in class [Reader](../../java/io/Reader.html "class in java.io")

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](../../java/io/IOException.html "class in java.io") - If an I/O error occurs

markSupported

public boolean markSupported()

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

Overrides:

[markSupported](../../java/io/Reader.html#markSupported%28%29) in class [Reader](../../java/io/Reader.html "class in java.io")

Returns:

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

mark

public void mark(int readAheadLimit) throws IOException

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

Overrides:

[mark](../../java/io/Reader.html#mark%28int%29) in class [Reader](../../java/io/Reader.html "class in java.io")

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](../../java/io/IOException.html "class in java.io") - If an I/O error occurs

reset

public void reset() throws IOException

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

Overrides:

[reset](../../java/io/Reader.html#reset%28%29) in class [Reader](../../java/io/Reader.html "class in java.io")

Throws:

[IOException](../../java/io/IOException.html "class in java.io") - If an I/O error occurs

close

public void close()

Close the stream.

Specified by:

[close](../../java/io/Closeable.html#close%28%29) in interface [Closeable](../../java/io/Closeable.html "interface in java.io")

Specified by:

[close](../../java/io/Reader.html#close%28%29) in class [Reader](../../java/io/Reader.html "class in java.io")

Submit a bug or feature
For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.