Package org.htmlparser.lexer

Class Source

  • All Implemented Interfaces:
    java.io.Closeable, java.io.Serializable, java.lang.AutoCloseable, java.lang.Readable
    Direct Known Subclasses:
    InputStreamSource, StringSource
    public abstract class Source
extends java.io.Reader
implements java.io.Serializable
    A buffered source of characters. A Source is very similar to a Reader, like: 
     new InputStreamReader (connection.getInputStream (), charset)
    It differs from the above, in three ways:
    • the fetching of bytes may be asynchronous
    • the character set may be changed, which resets the input stream
    • characters may be requested more than once, so in general they will be buffered
    See Also:
    Serialized Form

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static int EOF
      Return value when the source is exhausted.

      • Fields inherited from class java.io.Reader

        lock

    • Constructor Summary

      Constructors 
      Constructor Description
      Source()  

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      abstract int available()
      Get the number of available characters.
      abstract void close()
      Does nothing.
      abstract void destroy()
      Close the source.
      abstract char getCharacter​(int offset)
      Retrieve a character again.
      abstract void getCharacters​(char[] array, int offset, int start, int end)
      Retrieve characters again.
      abstract void getCharacters​(java.lang.StringBuffer buffer, int offset, int length)
      Append characters already read into a StringBuffer.
      abstract java.lang.String getEncoding()
      Get the encoding being used to convert characters.
      abstract java.lang.String getString​(int offset, int length)
      Retrieve a string comprised of characters already read.
      abstract void mark​(int readAheadLimit)
      Mark the present position.
      abstract boolean markSupported()
      Tell whether this source supports the mark() operation.
      abstract int offset()
      Get the position (in characters).
      abstract int read()
      Read a single character.
      abstract int read​(char[] cbuf)
      Read characters into an array.
      abstract int read​(char[] cbuf, int off, int len)
      Read characters into a portion of an array.
      abstract boolean ready()
      Tell whether this source is ready to be read.
      abstract void reset()
      Reset the source.
      abstract void setEncoding​(java.lang.String character_set)
      Set the encoding to the given character set.
      abstract long skip​(long n)
      Skip characters.
      abstract void unread()
      Undo the read of a single character.

      • Methods inherited from class java.io.Reader

        nullReader, read, transferTo

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • EOF

        public static final int EOF
        Return value when the source is exhausted. Has a value of -1.
        See Also:
        Constant Field Values

    • Constructor Detail

      • Source

        public Source()

    • Method Detail

      • getEncoding

        public abstract java.lang.String getEncoding()
        Get the encoding being used to convert characters.
        Returns:
        The current encoding.

      • setEncoding

        public abstract void setEncoding​(java.lang.String character_set)
                          throws ParserException
        Set the encoding to the given character set. If the current encoding is the same as the requested encoding, this method is a no-op. Otherwise any subsequent characters read from this source will have been decoded using the given character set.

        If characters have already been consumed from this source, it is expected that an exception will be thrown if the characters read so far would be different if the encoding being set was used from the start.

        Parameters:
        character_set - The character set to use to convert characters.
        Throws:
        ParserException - If a character mismatch occurs between characters already provided and those that would have been returned had the new character set been in effect from the beginning. An exception is also thrown if the character set is not recognized.

      • close

        public abstract void close()
                    throws java.io.IOException
        Does nothing. It's supposed to close the source, but use destroy() instead.
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Specified by:
        close in class java.io.Reader
        Throws:
        java.io.IOException - not used
        See Also:
        destroy()

      • read

        public abstract int read()
                  throws java.io.IOException
        Read a single character. This method will block until a character is available, an I/O error occurs, or the source is exhausted.
        Overrides:
        read in class java.io.Reader
        Returns:
        The character read, as an integer in the range 0 to 65535 (0x00-0xffff), or EOF if the source is exhausted.
        Throws:
        java.io.IOException - If an I/O error occurs.

      • read

        public abstract int read​(char[] cbuf,
                         int off,
                         int len)
                  throws java.io.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 source is exhausted.
        Specified by:
        read in class java.io.Reader
        Parameters:
        cbuf - Destination buffer
        off - Offset at which to start storing characters
        len - Maximum number of characters to read
        Returns:
        The number of characters read, or EOF if the source is exhausted.
        Throws:
        java.io.IOException - If an I/O error occurs.

      • read

        public abstract int read​(char[] cbuf)
                  throws java.io.IOException
        Read characters into an array. This method will block until some input is available, an I/O error occurs, or the source is exhausted.
        Overrides:
        read in class java.io.Reader
        Parameters:
        cbuf - Destination buffer.
        Returns:
        The number of characters read, or EOF if the source is exhausted.
        Throws:
        java.io.IOException - If an I/O error occurs.

      • ready

        public abstract boolean ready()
                       throws java.io.IOException
        Tell whether this source is ready to be read.
        Overrides:
        ready in class java.io.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:
        java.io.IOException - If an I/O error occurs.

      • reset

        public abstract void reset()
        Reset the source. Repositions the read point to begin at zero.
        Overrides:
        reset in class java.io.Reader

      • markSupported

        public abstract boolean markSupported()
        Tell whether this source supports the mark() operation.
        Overrides:
        markSupported in class java.io.Reader
        Returns:
        true if and only if this source supports the mark operation.

      • mark

        public abstract void mark​(int readAheadLimit)
                   throws java.io.IOException
        Mark the present position. Subsequent calls to reset() will attempt to reposition the source to this point. Not all sources support the mark() operation.
        Overrides:
        mark in class java.io.Reader
        Parameters:
        readAheadLimit - The minimum number of characters that can be read before this mark becomes invalid.
        Throws:
        java.io.IOException - If an I/O error occurs.

      • skip

        public abstract long skip​(long n)
                   throws java.io.IOException
        Skip characters. This method will block until some characters are available, an I/O error occurs, or the source is exhausted. Note: n is treated as an int
        Overrides:
        skip in class java.io.Reader
        Parameters:
        n - The number of characters to skip.
        Returns:
        The number of characters actually skipped
        Throws:
        java.io.IOException - If an I/O error occurs.

      • unread

        public abstract void unread()
                     throws java.io.IOException
        Undo the read of a single character.
        Throws:
        java.io.IOException - If the source is closed or no characters have been read.

      • getCharacter

        public abstract char getCharacter​(int offset)
                           throws java.io.IOException
        Retrieve a character again.
        Parameters:
        offset - The offset of the character.
        Returns:
        The character at offset.
        Throws:
        java.io.IOException - If the source is closed or the offset is beyond offset().

      • getCharacters

        public abstract void getCharacters​(char[] array,
                                   int offset,
                                   int start,
                                   int end)
                            throws java.io.IOException
        Retrieve characters again.
        Parameters:
        array - The array of characters.
        offset - The starting position in the array where characters are to be placed.
        start - The starting position, zero based.
        end - The ending position (exclusive, i.e. the character at the ending position is not included), zero based.
        Throws:
        java.io.IOException - If the source is closed or the start or end is beyond offset().

      • getString

        public abstract java.lang.String getString​(int offset,
                                           int length)
                                    throws java.io.IOException
        Retrieve a string comprised of characters already read.
        Parameters:
        offset - The offset of the first character.
        length - The number of characters to retrieve.
        Returns:
        A string containing the length characters at offset.
        Throws:
        java.io.IOException - If the source is closed.

      • getCharacters

        public abstract void getCharacters​(java.lang.StringBuffer buffer,
                                   int offset,
                                   int length)
                            throws java.io.IOException
        Append characters already read into a StringBuffer.
        Parameters:
        buffer - The buffer to append to.
        offset - The offset of the first character.
        length - The number of characters to retrieve.
        Throws:
        java.io.IOException - If the source is closed or the offset or (offset + length) is beyond offset().

      • destroy

        public abstract void destroy()
                      throws java.io.IOException
        Close the source. Once a source has been closed, further read, ready, mark, reset, skip, unread, getCharacter or getString invocations will throw an IOException. Closing a previously-closed source, however, has no effect.
        Throws:
        java.io.IOException - If an I/O error occurs.

      • offset

        public abstract int offset()
        Get the position (in characters).
        Returns:
        The number of characters that have already been read, or EOF if the source is closed.

      • available

        public abstract int available()
        Get the number of available characters.
        Returns:
        The number of characters that can be read without blocking.