CharArrayReader (Java Platform SE 6) (original) (raw)

java.io

Class CharArrayReader

java.lang.Object 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

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.

CharArrayReader

public CharArrayReader(char[] buf)

Creates a CharArrayReader from the specified array of chars.

Parameters:

buf - Input buffer (not copied)

CharArrayReader

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 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.

read

public int read() throws IOException

Reads 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

Reads 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

Skips 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

Tells 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()

Tells 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

Marks 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

Resets 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()

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.

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")

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