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Java™ Platform Standard Ed. 6 |
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java.lang.Object java.io.Reader
public abstract class Reader
Abstract class for reading character streams. The only methods that a subclass must implement are read(char[], int, int) and close(). Most subclasses, however, will override some of the methods defined here in order to provide higher efficiency, additional functionality, or both.
BufferedReader
,
LineNumberReader
,
CharArrayReader
,
InputStreamReader
,
FileReader
,
FilterReader
,
PushbackReader
,
PipedReader
,
StringReader
,
Writer
Field Summary | |
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protected Object |
lock
The object used to synchronize operations on this stream. |
Constructor Summary | |
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protected |
Reader()
Creates a new character-stream reader whose critical sections will synchronize on the reader itself. |
protected |
Reader(Object lock)
Creates a new character-stream reader whose critical sections will synchronize on the given object. |
Method Summary | |
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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. |
int |
read()
Reads a single character. |
int |
read(char[] cbuf)
Reads characters into an array. |
abstract int |
read(char[] cbuf,
int off,
int len)
Reads characters into a portion of 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. |
Methods inherited from class java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
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protected Object lock
Constructor Detail |
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protected Reader()
protected Reader(Object lock)
lock
- The Object to synchronize on.Method Detail |
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public int read(CharBuffer target) throws IOException
read
in interface Readable
target
- the buffer to read characters into
IOException
- if an I/O error occurs
NullPointerException
- if target is null
ReadOnlyBufferException
- if target is a read only bufferpublic int read() throws IOException
Subclasses that intend to support efficient single-character input should override this method.
IOException
- If an I/O error occurspublic int read(char[] cbuf) throws IOException
cbuf
- Destination buffer
IOException
- If an I/O error occurspublic abstract int read(char[] cbuf, int off, int len) throws IOException
cbuf
- Destination bufferoff
- Offset at which to start storing characterslen
- Maximum number of characters to read
IOException
- If an I/O error occurspublic long skip(long n) throws IOException
n
- The number of characters to skip
IllegalArgumentException
- If n
is negative.
IOException
- If an I/O error occurspublic boolean ready() throws IOException
IOException
- If an I/O error occurspublic boolean markSupported()
public void mark(int readAheadLimit) throws IOException
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.
IOException
- If the stream does not support mark(),
or if some other I/O error occurspublic void reset() throws IOException
IOException
- If the stream has not been marked,
or if the mark has been invalidated,
or if the stream does not support reset(),
or if some other I/O error occurspublic abstract void close() throws IOException
close
in interface Closeable
IOException
- If an I/O error occurs
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Java™ Platform Standard Ed. 6 |
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