程序包 java.io

类 FilterReader

java.lang.Object

java.io.Reader

java.io.FilterReader

所有已实现的接口:

Closeable, AutoCloseable, Readable

直接已知子类:

PushbackReader

public abstract class FilterReader
extends Reader

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.

从以下版本开始:

JDK1.1

字段概要

字段

限定符和类型	字段	说明
protected Reader	in	The underlying character-input stream.

从类继承的字段 java.io.Reader

lock

构造器概要

构造器

限定符	构造器	说明
protected	FilterReader(Reader in)	Creates a new filtered reader.

方法概要

限定符和类型	方法	说明
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.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

从类继承的方法 java.io.Reader

read, read

字段详细资料

in

protected Reader in

The underlying character-input stream.

构造器详细资料

FilterReader

protected FilterReader(Reader in)

Creates a new filtered reader.

参数:

in - a Reader object providing the underlying stream.

抛出:

NullPointerException - if in is null

方法详细资料

read

public int read()
         throws IOException

Reads a single character.

覆盖:

read 在类中 Reader

返回:

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

抛出:

IOException - If an I/O error occurs

read

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

Reads characters into a portion of an array.

指定者:

read 在类中 Reader

参数:

cbuf - Destination buffer

off - Offset at which to start storing characters

len - Maximum number of characters to read

返回:

The number of characters read, or -1 if the end of the stream has been reached

抛出:

IOException - If an I/O error occurs

skip

public long skip(long n)
          throws IOException

Skips characters.

覆盖:

skip 在类中 Reader

参数:

n - The number of characters to skip

返回:

The number of characters actually skipped

抛出:

IOException - If an I/O error occurs

ready

public boolean ready()
              throws IOException

Tells whether this stream is ready to be read.

覆盖:

ready 在类中 Reader

返回:

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.

抛出:

IOException - If an I/O error occurs

markSupported

public boolean markSupported()

Tells whether this stream supports the mark() operation.

覆盖:

markSupported 在类中 Reader

返回:

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.

覆盖:

mark 在类中 Reader

参数:

readAheadLimit - 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.

抛出:

IOException - If an I/O error occurs

reset

public void reset()
           throws IOException

Resets the stream.

覆盖:

reset 在类中 Reader

抛出:

IOException - If an I/O error occurs

close

public void close()
           throws IOException

从类复制的说明: Reader

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.

指定者:

close 在接口中 AutoCloseable

指定者:

close 在接口中 Closeable

指定者:

close 在类中 Reader

抛出:

IOException - If an I/O error occurs