FilterReader

public abstract class FilterReader
extends Reader

java.lang.Object
   ↳ java.io.Reader
     ↳ java.io.FilterReader


Abstract class for reading filtered character streams. The abstract class FilterReader itself provides default methods that pass all requests to the contained stream. Subclasses of FilterReader should override some of these methods and may also provide additional methods and fields.

Summary

Fields

protected Reader in

The underlying character-input stream.

Inherited fields

Protected constructors

FilterReader(Reader in)

Creates a new filtered reader.

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.

int read()

Reads a single character.

int read(char[] cbuf, 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.

long skip(long n)

Skips characters.

Inherited methods

Fields

in

Added in API level 1
protected Reader in

The underlying character-input stream.

Protected constructors

FilterReader

Added in API level 1
protected FilterReader (Reader in)

Creates a new filtered reader.

Parameters
in Reader: a Reader object providing the underlying stream.

Throws
NullPointerException if in is null

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.

Throws
IOException

mark

Added in API level 1
public void mark (int readAheadLimit)

Marks the present position in the stream.

Parameters
readAheadLimit int: Limit on the number of characters that may be read while still preserving the mark. After reading this many characters, attempting to reset the stream may fail.

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.

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[] cbuf, 
                int off, 
                int len)

Reads characters into a portion of an array.

Parameters
cbuf char: Destination buffer

off int: Offset at which to start storing characters

len int: Maximum number of characters to read

Returns
int The 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.

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.

Throws
IOException If an I/O error occurs

skip

Added in API level 1
public long skip (long n)

Skips characters.

Parameters
n long: The number of characters to skip

Returns
long The number of characters actually skipped

Throws
IOException If an I/O error occurs