PushbackReader (Java 2 Platform SE v1.4.2) - Java 2 SDK v1.4.2, Java 2 SDK 英文文档

Overview

Package

Class

Use

Tree

Deprecated

Index

Help

Java^TM 2 Platform
Std. Ed. v1.4.2

PREV CLASS NEXT CLASS

FRAMES NO FRAMES

SUMMARY: NESTED | FIELD | CONSTR | METHOD

DETAIL: FIELD | CONSTR | METHOD

java.io
Class 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.

Since:: JDK1.1

Field Summary

Fields inherited from class java.io.FilterReader

in

Fields inherited from class java.io.Reader

lock

Constructor Summary

PushbackReader(Reader in)
          Create a new pushback reader with a one-character pushback buffer.

PushbackReader(Reader in, int size)
          Create a new pushback reader with a pushback buffer of the given size.

Method Summary

void close()
          Close the stream.

void mark(int readAheadLimit)
          Mark the present position in the stream.

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

int read()
          Read a single character.

int read(char[] cbuf, int off, int len)
          Read characters into a portion of an array.

boolean ready()
          Tell whether this stream is ready to be read.

void reset()
          Reset the stream.

long skip(long n)
          Skip characters.

void unread(char[] cbuf)
          Push back an array of characters by copying it to the front of the pushback buffer.

void unread(char[] cbuf, int off, int len)
          Push back a portion of an array of characters by copying it to the front of the pushback buffer.

void unread(int c)
          Push back a single character.

Methods inherited from class java.io.Reader

read

Methods inherited from class java.lang.Object

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

Constructor Detail

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
Throws:: IllegalArgumentException - if size is <= 0

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

Method Detail

read

public int read()
         throws IOException

Read a single character.

Overrides:: read in class FilterReader

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

read

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

Read characters into a portion of an array.

Overrides:: read in class FilterReader

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

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.

Overrides:: ready in class FilterReader

Throws:: IOException - If an I/O error occurs

mark

public void mark(int readAheadLimit)
          throws IOException

Mark the present position in the stream. The mark for class PushbackReader always throws an exception.

Overrides:: mark in class FilterReader

Throws:: IOException - Always, since mark is not supported

reset

public void reset()
           throws IOException

Reset the stream. The reset method of PushbackReader always throws an exception.

Overrides:: reset in class FilterReader

Throws:: IOException - Always, since reset is not supported

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.

Overrides:: close in class FilterReader

Throws:: IOException - If an I/O error occurs

skip

public long skip(long n)
          throws IOException

Skip characters. This method will block until some characters are available, an I/O error occurs, or the end of the stream is reached.

Overrides:: skip in class FilterReader

Parameters:: n - The number of characters to skip
Returns:: The number of characters actually skipped
Throws:: IllegalArgumentException - If n is negative.; IOException - If an I/O error occurs

Overview

Package

Class

Use

Tree

Deprecated

Index

Help

Java^TM 2 Platform
Std. Ed. v1.4.2

PREV CLASS NEXT CLASS

FRAMES NO FRAMES

SUMMARY: NESTED | FIELD | CONSTR | METHOD

DETAIL: FIELD | CONSTR | METHOD

Submit a bug or feature
For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

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

Method Summary
`void`	`close()` Close the stream.
`void`	`mark(int readAheadLimit)` Mark the present position in the stream.
`boolean`	`markSupported()` Tell whether this stream supports the mark() operation, which it does not.
`int`	`read()` Read a single character.
`int`	`read(char[] cbuf, int off, int len)` Read characters into a portion of an array.
`boolean`	`ready()` Tell whether this stream is ready to be read.
`void`	`reset()` Reset the stream.
`long`	`skip(long n)` Skip characters.
`void`	`unread(char[] cbuf)` Push back an array of characters by copying it to the front of the pushback buffer.
`void`	`unread(char[] cbuf, int off, int len)` Push back a portion of an array of characters by copying it to the front of the pushback buffer.
`void`	`unread(int c)` Push back a single character.

PushbackReader (Java 2 Platform SE v1.4.2) - Java 2 SDK v1.4.2, Java 2 SDK 英文文档

java.io Class PushbackReader

PushbackReader

PushbackReader

read

read

unread

unread

unread

ready

mark

reset

markSupported

close

skip

java.io
Class PushbackReader