CharArrayReader (Java Platform SE 7 ) (original) (raw)

• java.lang.Object

• • java.io.Reader
  • • java.io.CharArrayReader

• All Implemented Interfaces:
  Closeable, AutoCloseable, Readable

public class CharArrayReader
extends Reader
This class implements a character buffer that can be used as a character-input stream.
Since:
JDK1.1

• • Field Summary

  Fields

  Modifier and Type	Field and Description
  protected char[]	buf The character buffer.
  protected int	count The index of the end of this buffer.
  protected int	markedPos The position of mark in buffer.
  protected int	pos The current buffer position.

     * ### Fields inherited from class java.io.[Reader](../../java/io/Reader.html "class in java.io")  
     `[lock](../../java/io/Reader.html#lock)`  

  • Constructor Summary

  Constructors

  Constructor and Description
  CharArrayReader(char[] buf) Creates a CharArrayReader from the specified array of chars.
  CharArrayReader(char[] buf, int offset, int length) Creates a CharArrayReader from the specified array of chars.

  • Method Summary

  Methods

  Modifier and Type	Method and Description
  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, which it does.
  int	read() Reads a single character.
  int	read(char[] b, int off, int len) Reads characters into a portion of an array.
  boolean	ready() Tells whether this stream is ready to be read.
  void	reset() Resets the stream to the most recent mark, or to the beginning if it has never been marked.
  long	skip(long n) Skips characters.

     * ### Methods inherited from class java.io.[Reader](../../java/io/Reader.html "class in java.io")  
     `[read](../../java/io/Reader.html#read%28char[]%29), [read](../../java/io/Reader.html#read%28java.nio.CharBuffer%29)`  
     * ### Methods inherited from class java.lang.[Object](../../java/lang/Object.html "class in java.lang")  
     `[clone](../../java/lang/Object.html#clone%28%29), [equals](../../java/lang/Object.html#equals%28java.lang.Object%29), [finalize](../../java/lang/Object.html#finalize%28%29), [getClass](../../java/lang/Object.html#getClass%28%29), [hashCode](../../java/lang/Object.html#hashCode%28%29), [notify](../../java/lang/Object.html#notify%28%29), [notifyAll](../../java/lang/Object.html#notifyAll%28%29), [toString](../../java/lang/Object.html#toString%28%29), [wait](../../java/lang/Object.html#wait%28%29), [wait](../../java/lang/Object.html#wait%28long%29), [wait](../../java/lang/Object.html#wait%28long,%20int%29)`

• • Field Detail

     * #### buf  
     protected char[] buf  
     The character buffer.  
     * #### pos  
     protected int pos  
     The current buffer position.  
     * #### markedPos  
     protected int markedPos  
     The position of mark in buffer.  
     * #### count  
     protected int count  
     The index of the end of this buffer. There is not valid data at or beyond this index.  

  • Constructor Detail

    * #### CharArrayReader  
    public CharArrayReader(char[] buf)  
    Creates a CharArrayReader from the specified array of chars.  
    Parameters:  
    `buf` \- Input buffer (not copied)  
    * #### CharArrayReader  
    public CharArrayReader(char[] buf,  
                   int offset,  
                   int length)  
    Creates a CharArrayReader from the specified array of chars.  
     The resulting reader will start reading at the givenoffset. The total number of char values that can be read from this reader will be either length orbuf.length-offset, whichever is smaller.  
    Parameters:  
    `buf` \- Input buffer (not copied)  
    `offset` \- Offset of the first char to read  
    `length` \- Number of chars to read  
    Throws:  
    `[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- If offset is negative or greater thanbuf.length, or if length is negative, or if the sum of these two values is negative.  

  • Method Detail

    * #### read  
    public int read()  
             throws [IOException](../../java/io/IOException.html "class in java.io")  
    Reads a single character.  
    **Overrides:**  
    `[read](../../java/io/Reader.html#read%28%29)` in class `[Reader](../../java/io/Reader.html "class in java.io")`  
    Returns:  
    The character read, as an integer in the range 0 to 65535 (0x00-0xffff), or -1 if the end of the stream has been reached  
    Throws:  
    `[IOException](../../java/io/IOException.html "class in java.io")` \- If an I/O error occurs  
    * #### read  
    public int read(char[] b,  
           int off,  
           int len)  
             throws [IOException](../../java/io/IOException.html "class in java.io")  
    Reads characters into a portion of an array.  
    **Specified by:**  
    `[read](../../java/io/Reader.html#read%28char[],%20int,%20int%29)` in class `[Reader](../../java/io/Reader.html "class in java.io")`  
    Parameters:  
    `b` \- Destination buffer  
    `off` \- Offset at which to start storing characters  
    `len` \- Maximum number of characters to read  
    Returns:  
    The actual number of characters read, or -1 if the end of the stream has been reached  
    Throws:  
    `[IOException](../../java/io/IOException.html "class in java.io")` \- If an I/O error occurs  
    * #### skip  
    public long skip(long n)  
              throws [IOException](../../java/io/IOException.html "class in java.io")  
    Skips characters. Returns the number of characters that were skipped.  
    The `n` parameter may be negative, even though the`skip` method of the [Reader](../../java/io/Reader.html "class in java.io") superclass throws an exception in this case. If `n` is negative, then this method does nothing and returns `0`.  
    **Overrides:**  
    `[skip](../../java/io/Reader.html#skip%28long%29)` in class `[Reader](../../java/io/Reader.html "class in java.io")`  
    Parameters:  
    `n` \- The number of characters to skip  
    Returns:  
    The number of characters actually skipped  
    Throws:  
    `[IOException](../../java/io/IOException.html "class in java.io")` \- If the stream is closed, or an I/O error occurs  
    * #### ready  
    public boolean ready()  
                  throws [IOException](../../java/io/IOException.html "class in java.io")  
    Tells whether this stream is ready to be read. Character-array readers are always ready to be read.  
    **Overrides:**  
    `[ready](../../java/io/Reader.html#ready%28%29)` in class `[Reader](../../java/io/Reader.html "class in java.io")`  
    Returns:  
    True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.  
    Throws:  
    `[IOException](../../java/io/IOException.html "class in java.io")` \- If an I/O error occurs  
    * #### markSupported  
    public boolean markSupported()  
    Tells whether this stream supports the mark() operation, which it does.  
    **Overrides:**  
    `[markSupported](../../java/io/Reader.html#markSupported%28%29)` in class `[Reader](../../java/io/Reader.html "class in java.io")`  
    Returns:  
    true if and only if this stream supports the mark operation.  
    * #### mark  
    public void mark(int readAheadLimit)  
              throws [IOException](../../java/io/IOException.html "class in java.io")  
    Marks the present position in the stream. Subsequent calls to reset() will reposition the stream to this point.  
    **Overrides:**  
    `[mark](../../java/io/Reader.html#mark%28int%29)` in class `[Reader](../../java/io/Reader.html "class in java.io")`  
    Parameters:  
    `readAheadLimit` \- Limit on the number of characters that may be read while still preserving the mark. Because the stream's input comes from a character array, there is no actual limit; hence this argument is ignored.  
    Throws:  
    `[IOException](../../java/io/IOException.html "class in java.io")` \- If an I/O error occurs  
    * #### reset  
    public void reset()  
               throws [IOException](../../java/io/IOException.html "class in java.io")  
    Resets the stream to the most recent mark, or to the beginning if it has never been marked.  
    **Overrides:**  
    `[reset](../../java/io/Reader.html#reset%28%29)` in class `[Reader](../../java/io/Reader.html "class in java.io")`  
    Throws:  
    `[IOException](../../java/io/IOException.html "class in java.io")` \- If an I/O error occurs  
    * #### close  
    public void close()  
    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.  
    **Specified by:**  
    `[close](../../java/io/Closeable.html#close%28%29)` in interface `[Closeable](../../java/io/Closeable.html "interface in java.io")`  
    **Specified by:**  
    `[close](../../java/lang/AutoCloseable.html#close%28%29)` in interface `[AutoCloseable](../../java/lang/AutoCloseable.html "interface in java.lang")`  
    **Specified by:**  
    `[close](../../java/io/Reader.html#close%28%29)` in class `[Reader](../../java/io/Reader.html "class in java.io")`

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