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java.io
abstract public class: Reader [javadoc | source]
java.lang.Object
   java.io.Reader

All Implemented Interfaces:
    Closeable, Readable

Direct Known Subclasses:
    LineReader, FileReader, StringReader, LineNumberReader, PushbackReader, CharArrayReader, InputStreamReader, PipedReader, BufferedReader, FilterReader

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.
Field Summary
protected  Object lock    The object used to synchronize operations on this stream. For efficiency, a character-stream object may use an object other than itself to protect critical sections. A subclass should therefore use the object in this field rather than this or a synchronized method. 
Constructor:
 protected Reader() 
 protected Reader(Object lock) 
    Creates a new character-stream reader whose critical sections will synchronize on the given object.
    Parameters:
    lock - The Object to synchronize on.
Method from java.io.Reader Summary:
close,   mark,   markSupported,   read,   read,   read,   read,   ready,   reset,   skip
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from java.io.Reader Detail:
 abstract public  void close() throws IOException
    Closes the stream and releases any system resources associated with it. Once the stream has been closed, further read(), ready(), mark(), reset(), or skip() invocations will throw an IOException. Closing a previously closed stream has no effect.
 public  void mark(int readAheadLimit) throws IOException 
    Marks the present position in the stream. Subsequent calls to reset() will attempt to reposition the stream to this point. Not all character-input streams support the mark() operation.
 public boolean markSupported() 
    Tells whether this stream supports the mark() operation. The default implementation always returns false. Subclasses should override this method.
 public int read() throws IOException 
    Reads a single character. This method will block until a character is available, an I/O error occurs, or the end of the stream is reached.

    Subclasses that intend to support efficient single-character input should override this method.

 public int read(CharBuffer target) throws IOException 
    Attempts to read characters into the specified character buffer. The buffer is used as a repository of characters as-is: the only changes made are the results of a put operation. No flipping or rewinding of the buffer is performed.
 public int read(char[] cbuf) throws IOException 
    Reads characters into an array. This method will block until some input is available, an I/O error occurs, or the end of the stream is reached.
 abstract public int read(char[] cbuf,
    int off,
    int len) throws IOException
    Reads characters into a portion of an array. This method will block until some input is available, an I/O error occurs, or the end of the stream is reached.
 public boolean ready() throws IOException 
    Tells whether this stream is ready to be read.
 public  void reset() throws IOException 
    Resets the stream. If the stream has been marked, then attempt to reposition it at the mark. If the stream has not been marked, then attempt to reset it in some way appropriate to the particular stream, for example by repositioning it to its starting point. Not all character-input streams support the reset() operation, and some support reset() without supporting mark().
 public long skip(long n) throws IOException 
    Skips characters. This method will block until some characters are available, an I/O error occurs, or the end of the stream is reached.