| Java 1.1 | readable closeable |
This abstract class
is the superclass of all character input streams. It is an analog to
InputStream, which is the superclass of all byte
input streams. Reader defines the basic methods
that all character output streams provide. read(
) returns a single character or an array
(or subarray) of characters, blocking if necessary; it returns -1 if
the end of the stream has been reached. ready(
) returns true if
there are characters available for reading. If ready(
) returns TRue, the next call to
read( ) is guaranteed not to block.
close( ) closes the
character input stream. skip(
) skips a specified number of characters
in the input stream. If markSupported(
)
returns true,
mark( ) marks a position in the stream and, if
necessary, creates a look-ahead buffer of the specified size. Future
calls to reset( ) restore
the stream to the marked position if they occur within the specified
look-ahead limit. Note that not all stream types support this
mark-and-reset functionality. To create a subclass of
Reader, you need only implement the three-argument
version of read( ) and the close(
) method. Most subclasses implement additional methods,
however.
Figure 9-54. java.io.Reader
public abstract class Reader implements Closeable, Readable {
// Protected Constructors
protected Reader ( );
protected Reader (Object lock );
// Public Instance Methods
public abstract void close ( ) throws IOException; Implements:Closeable
public void mark (int readAheadLimit ) throws IOException;
public boolean markSupported ( ); constant
public int read ( ) throws IOException;
public int read (char[ ] cbuf ) throws IOException;
public abstract int read (char[ ] cbuf , int off , int len ) throws IOException;
public boolean ready ( ) throws IOException; constant
public void reset ( ) throws IOException;
public long skip (long n ) throws IOException;
// Methods Implementing Closeable
public abstract void close ( ) throws IOException;
// Methods Implementing Readable
5.0 public int read (java.nio.CharBuffer target ) throws IOException;
// Protected Instance Fields
protected Object lock ;
}
Subclasses
BufferedReader,
CharArrayReader, FilterReader,
InputStreamReader, PipedReader,
StringReader Passed To
BufferedReader.BufferedReader( ),
FilterReader.FilterReader( ),
LineNumberReader.LineNumberReader( ),
PushbackReader.PushbackReader( ),
StreamTokenizer.StreamTokenizer( ),
javax.xml.transform.stream.StreamSource.{setReader(
), StreamSource( )},
org.xml.sax.InputSource.{InputSource( ),
setCharacterStream( )} Returned By
java.nio.channels.Channels.newReader( ),
javax.xml.transform.stream.StreamSource.getReader(
), org.xml.sax.InputSource.getCharacterStream(
) Type Of
FilterReader.in |