Class UCSReader

  • All Implemented Interfaces:
    Closeable, AutoCloseable, Readable

    public final class UCSReader
    extends Reader
    Reader for UCS-2 and UCS-4 encodings. (i.e., encodings from ISO-10646-UCS-(2|4)).
    Version:
    $Id$
    Author:
    Neil Graham, IBM
    • Field Summary

      Fields 
      Modifier and Type Field Description
      static int DEFAULT_BUFFER_SIZE
      Default byte buffer size (8192, larger than that of ASCIIReader since it's reasonable to surmise that the average UCS-4-encoded file should be 4 times as large as the average ASCII-encoded file).
      protected byte[] fBuffer
      Byte buffer.
      protected short fEncoding  
      protected InputStream fInputStream
      Input stream.
      static short UCS2BE  
      static short UCS2LE  
      static short UCS4BE  
      static short UCS4LE  
    • Constructor Summary

      Constructors 
      Constructor Description
      UCSReader​(InputStream inputStream, byte[] buffer, short encoding)
      Constructs a UCS reader from the specified input stream and buffer.
      UCSReader​(InputStream inputStream, int size, short encoding)
      Constructs a UCS reader from the specified input stream and buffer size.
      UCSReader​(InputStream inputStream, short encoding)
      Constructs a UCS reader from the specified input stream using the default buffer size.
    • Field Detail

      • DEFAULT_BUFFER_SIZE

        public static final int DEFAULT_BUFFER_SIZE
        Default byte buffer size (8192, larger than that of ASCIIReader since it's reasonable to surmise that the average UCS-4-encoded file should be 4 times as large as the average ASCII-encoded file).
        See Also:
        Constant Field Values
      • fInputStream

        protected final InputStream fInputStream
        Input stream.
      • fBuffer

        protected final byte[] fBuffer
        Byte buffer.
      • fEncoding

        protected final short fEncoding
    • Constructor Detail

      • UCSReader

        public UCSReader​(InputStream inputStream,
                         short encoding)
        Constructs a UCS reader from the specified input stream using the default buffer size. The Endian-ness and whether this is UCS-2 or UCS-4 needs also to be known in advance.
        Parameters:
        inputStream - The input stream.
        encoding - One of UCS2LE, UCS2BE, UCS4LE or UCS4BE.
      • UCSReader

        public UCSReader​(InputStream inputStream,
                         int size,
                         short encoding)
        Constructs a UCS reader from the specified input stream and buffer size. The Endian-ness and whether this is UCS-2 or UCS-4 needs also to be known in advance.
        Parameters:
        inputStream - The input stream.
        size - The initial buffer size.
        encoding - One of UCS2LE, UCS2BE, UCS4LE or UCS4BE.
      • UCSReader

        public UCSReader​(InputStream inputStream,
                         byte[] buffer,
                         short encoding)
        Constructs a UCS reader from the specified input stream and buffer. The Endian-ness and whether this is UCS-2 or UCS-4 needs also to be known in advance.
        Parameters:
        inputStream - The input stream.
        buffer - The byte buffer.
        encoding - One of UCS2LE, UCS2BE, UCS4LE or UCS4BE.
    • Method Detail

      • read

        public int read()
                 throws IOException
        Read 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.

        Overrides:
        read in class Reader
        Returns:
        The character read, as an integer in the range 0 to 127 (0x00-0x7f), or -1 if the end of the stream has been reached
        Throws:
        IOException - If an I/O error occurs
      • read

        public int read​(char[] ch,
                        int offset,
                        int length)
                 throws IOException
        Read 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.
        Specified by:
        read in class Reader
        Parameters:
        ch - Destination buffer
        offset - Offset at which to start storing characters
        length - Maximum number of characters to read
        Returns:
        The number of characters read, or -1 if the end of the stream has been reached
        Throws:
        IOException - If an I/O error occurs
      • skip

        public long skip​(long n)
                  throws IOException
        Skip characters. This method will block until some characters are available, an I/O error occurs, or the end of the stream is reached.
        Overrides:
        skip in class Reader
        Parameters:
        n - The number of characters to skip
        Returns:
        The number of characters actually skipped
        Throws:
        IOException - If an I/O error occurs
      • ready

        public boolean ready()
                      throws IOException
        Tell whether this stream is ready to be read.
        Overrides:
        ready in class Reader
        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 - If an I/O error occurs
      • markSupported

        public boolean markSupported()
        Tell whether this stream supports the mark() operation.
        Overrides:
        markSupported in class Reader
      • mark

        public void mark​(int readAheadLimit)
                  throws IOException
        Mark 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.
        Overrides:
        mark in class Reader
        Parameters:
        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.
        Throws:
        IOException - If the stream does not support mark(), or if some other I/O error occurs
      • reset

        public void reset()
                   throws IOException
        Reset 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().
        Overrides:
        reset in class Reader
        Throws:
        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 occurs
      • close

        public void close()
                   throws IOException
        Close the stream. Once a stream has been closed, further read(), ready(), mark(), or reset() invocations will throw an IOException. Closing a previously-closed stream, however, has no effect.
        Specified by:
        close in interface AutoCloseable
        Specified by:
        close in interface Closeable
        Specified by:
        close in class Reader
        Throws:
        IOException - If an I/O error occurs