FilterReader

public abstract class FilterReader
extends Reader

java.lang.Object
   ↳ java.io.Reader
     ↳ java.io.FilterReader
PushbackReader A character-stream reader that allows characters to be pushed back into the stream. 


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 Object lock

The object used to synchronize operations on this stream.

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

abstract 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.

static Reader nullReader()

Returns a new Reader that reads no characters.

int read()

Reads a single character.

abstract int read(char[] cbuf, int off, int len)

Reads characters into a portion of an array.

int read(char[] cbuf)

Reads characters into an array.

int read(CharBuffer target)

Attempts to read characters into the specified character buffer.

boolean ready()

Tells whether this stream is ready to be read.

void reset()

Resets the stream.

long skip(long n)

Skips characters.

long transferTo(Writer out)

Reads all characters from this reader and writes the characters to the given writer in the order that they are read.

Object clone()

Creates and returns a copy of this object.

boolean equals(Object obj)

Indicates whether some other object is "equal to" this one.

void finalize()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

final Class<?> getClass()

Returns the runtime class of this Object.

int hashCode()

Returns a hash code value for the object.

final void notify()

Wakes up a single thread that is waiting on this object's monitor.

final void notifyAll()

Wakes up all threads that are waiting on this object's monitor.

String toString()

Returns a string representation of the object.

final void wait(long timeoutMillis, int nanos)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

final void wait(long timeoutMillis)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

final void wait()

Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

abstract void close()

Closes this stream and releases any system resources associated with it.

abstract int read(CharBuffer cb)

Attempts to read characters into the specified character buffer.

abstract void close()

Closes this resource, relinquishing any underlying resources.

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