Class java.io.PushbackReader - JDK 5 Documentation v1.1.8, Java 2 SDK 英文文档

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Class java.io.PushbackReader

java.lang.Object
   |
   +----java.io.Reader
           |
           +----java.io.FilterReader
                   |
                   +----java.io.PushbackReader

public class PushbackReader
extends FilterReader

A character-stream reader that allows characters to be pushed back into the stream.

PushbackReader(Reader): Create a new pushback reader with a one-character pushback buffer.
PushbackReader(Reader, int): Create a new pushback reader with a pushback buffer of the given size.

close(): Close the stream.
markSupported(): Tell whether this stream supports the mark() operation, which it does not.
read(): Read a single character.
read(char[], int, int): Read characters into a portion of an array.
ready(): Tell whether this stream is ready to be read.
unread(char[]): Push back an array of characters by copying it to the front of the pushback buffer.
unread(char[], int, int): Push back a portion of an array of characters by copying it to the front of the pushback buffer.
unread(int): Push back a single character.

PushbackReader

 public PushbackReader(Reader in,
                       int size)

Create a new pushback reader with a pushback buffer of the given size.

Parameters:: in - The reader from which characters will be read; size - The size of the pushback buffer

PushbackReader

 public PushbackReader(Reader in)

Create a new pushback reader with a one-character pushback buffer.

Parameters:: in - The reader from which characters will be read

read

 public int read() throws IOException

Read a single character.

Returns:: The character read, or -1 if the end of the stream has been reached
Throws: IOException: If an I/O error occurs
Overrides:: read in class FilterReader

read

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

Read characters into a portion of an array.

Parameters:: cbuf - Destination buffer; off - Offset at which to start writing characters; len - Maximum number of characters to read
Returns:: The number of characters read, or -1 if the end of the stream has been reached
Throws: IOException: If an I/O error occurs
Overrides:: read in class FilterReader

unread

 public void unread(int c) throws IOException

Push back a single character.

Parameters:: c - The character to push back
Throws: IOException: If the pushback buffer is full, or if some other I/O error occurs

unread

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

Push back a portion of an array of characters by copying it to the front of the pushback buffer. After this method returns, the next character to be read will have the value cbuf[off], the character after that will have the value cbuf[off+1], and so forth.

Parameters:: cbuf - Character array; off - Offset of first character to push back; len - Number of characters to push back
Throws: IOException: If there is insufficient room in the pushback buffer, or if some other I/O error occurs

unread

 public void unread(char cbuf[]) throws IOException

Push back an array of characters by copying it to the front of the pushback buffer. After this method returns, the next character to be read will have the value cbuf[0], the character after that will have the value cbuf[1], and so forth.

Parameters:: cbuf - Character array to push back
Throws: IOException: If there is insufficient room in the pushback buffer, or if some other I/O error occurs

ready

 public boolean ready() throws IOException

Tell whether this stream is ready to be read.

Throws: IOException: If an I/O error occurs
Overrides:: ready in class FilterReader

markSupported

 public boolean markSupported()

Tell whether this stream supports the mark() operation, which it does not.

Overrides:: markSupported in class FilterReader

close

 public void close() throws IOException

Close the stream.

Throws: IOException: If an I/O error occurs
Overrides:: close in class FilterReader

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