Reader

Reader

java.io

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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