currentdeck.java

一个用 java写的wap浏览器 对于浏览器感兴趣起的可以看看咯

/*
 * j2wap is distributed under the terms of the GNU Public License
 *
 *  j2wap was written by:
 *
 *	        Scott Campbell
 *			Michael Nordling
 *			Karl Maftoum
 * 			Julian Bright
 *
 *			This was a final project for Comp.Engineering at the University of Canberra, Australia
 *
 *			Now released as Open Source software. 28 November 2000
 *
 *			Email: [e-mail] for more info
 *
 *			Use entirely at your own risk.
 */
package wae;

import java.io.IOException;

/**
 * Title:       CurrentDeck
 * Description: The Current deck class our view of an WML deck. It contains
 *              a reference to an instance of DeckElement, which encapsulates a
 *              binary encoded WML deck.
 *
 *              CurrentDeck also provides functionality to extract a deck's
 *              version number, public identifier, charset and string table.
 *              It also keeps track of the deck's URL and whether it has a
 *              <code>template</code> element.
 * Company:     J2wap.com
 * @author      Scott Campbell.
 * @version     1.1
 */
public class CurrentDeck extends WbxmlUtility
{
  // Private attributes
  /** Flags if a TEMPLATE element has been found in the deck. */
  private boolean     c_bolHasTemplate;
  /** Holds the version number of the deck. */
  private int         c_intVersion;
  /** Holds the public identifier of the deck. */
  private int         c_intPublicIdentifierId;
  /** Holds the charset of the deck. */
  private int         c_intCharSet;
  /** Holds all strings contained in the deck's string table. */
  private char        c_arrStringTable[];
  /** Holds the base part of the deck's URL. */
  private String      c_strDeckBaseURL	      = new String ();
  /** Holds the tail of the deck's URL. */
  private String      c_strDeckURLTail	      = new String ();
  /** Holds the fragment ID of the deck's URL. */
  private String      c_strFragmentID;
  /** Object holding the deck. */
  private DeckElement c_clsDeckBytecode;


  /**
   * Get a new deck, extract string table, and parse deck elements.
   * This method parses all deck elements preceeding card elements.
   * @param in_clsDeckByteCode  Deck's bytecode.
   * @param in_clsDeckURL       The decks's absolute URL.
   */
  public void getDeck (byte in_clsDeckByteCode[], String in_clsDeckURL) throws IOException
  {
    c_clsDeckBytecode = new DeckElement (in_clsDeckByteCode);
    c_bolHasTemplate = false;

    // Get version and public identifier.
    c_intVersion = nextByte ();
    c_intPublicIdentifierId = readMultiByteInteger ();
    setDeckURL(in_clsDeckURL);

    // skip charset
    c_intCharSet = readMultiByteInteger ();

    // Get string table size and read in string table.
    int intStrTabSize = readMultiByteInteger ();
    this.c_arrStringTable = new char [intStrTabSize];
    for (int i = 0; i < intStrTabSize; i++)
      c_arrStringTable [i] = (char) nextByte ();

    // Set the WML start (<WML>) marker in the bytecode.
   this.c_clsDeckBytecode.setWmlStartPos ();
  } // getDeck

  /**
   * Read an inline string starting at the next byte in the deck's bytecode
   * array.
   * @return  The inline string read from the deck's bytecode.
   */
  public String readInlineString () throws IOException, J2WapException
  {
   StringBuffer clsStrBuf = new StringBuffer ();

    while (true)
    {
      // Read the next byte
      byte bytCurrentByte = c_clsDeckBytecode.nextByte ();

      // If valid byte, then append to string buffer
      if (bytCurrentByte == 0xFF)
      {
        J2WapException clsExep = new J2WapException (
          "Error: End of file " + "encountered while reading inline string.");
        throw (clsExep);
      } // if
      else if (bytCurrentByte == 0)
        return clsStrBuf.toString ();
      else clsStrBuf.append ((char) bytCurrentByte);
    } // while
  } // readInlineString

  /**
   * Read a string from the string table.<p>
   * This method will probably need to be used by the class
   * that parses the deck and divides the deck into cards.
   * @return  String that was read from the string table.
   */
 public String readStringFromStringTable () throws IOException
 {
  // Get the start and end positions of the string in the string table.
  int intPos = readMultiByteInteger ();
  int intEnd = intPos;
  // Find last character of string.
  while (c_arrStringTable [intEnd] != 0)
    intEnd++;

  return new String (c_arrStringTable, intPos, intEnd-intPos);
 } // readStringFromStringTable

  /**
   * Reads the next byte in the deck's bytecode array.
   * @return  The next byte in the deck's byte code array.
   */
  public byte nextByte()
  {
    return c_clsDeckBytecode.nextByte ();
  } // nextByte

  /**
   * Reads a multi byte integer from the deck's bytecode.
   * @return  The multibyte (mb_u_int32) integer read.
   */
    public int readMultiByteInteger () throws IOException
  {
    int intResult = 0;
    byte bytTemp;

    do
    {
        bytTemp = c_clsDeckBytecode.nextByte ();
        intResult = (intResult << 7) | (bytTemp & c_LowByteMask);
    }
    while (moreBytesInMBInt (bytTemp));

    return intResult;
    } // readMultiByteInteger

    /**
     * Get the position of the nextbyte to be read from the bytecode array.
     * @return  Position of the nextbyte.
     */
    public int posOfNextByte ()
    {
       return (c_clsDeckBytecode.nextPos ());
    } // posOfNextByte

    /**
     * Sets the next position indicator in the bytecode array  to the value
     * of "in_intPos". A subsequent call to the "nextByte ()" will return the
     * byte at the "in_intPost" position in the bytecode array.
     * @param in_intPos The index of the next byte that will be returned by a
     *                  call to <code>nextByte()</code>.
     */
    public void setPosOfNextBytecode (int in_intPos)
    {
      c_clsDeckBytecode.setNextPos(in_intPos);
    } // setPosOfNextBytecode

    /**
     * Marks the position of the <code>template</code> tag in the bytecode.
     */
    public void setTemplateStartPos ()
    {
      c_clsDeckBytecode.setTemplateStartPos ();
      c_bolHasTemplate = true;
    } // setTemplateStartPos

    /**
     * Resets the next position indicator in the bytecode array so that a
     * subsequent call the "nextByte ()" will return <code>WML</code> tag.
     */
    public void ResetToWmlStartPos ()
    {
      c_clsDeckBytecode.ResetToWmlStartPos ();
    } // ResetToWmlStartPos

    /**
     * Resets the next position indicator in the bytecode array so that a
     * subsequent call the "nextByte ()" will return <code>template</code> tag.
     */
    public void ResetToTemplateStartPos ()
    {
      c_clsDeckBytecode.ResetToTemplateStartPos ();
    } // ResetToTemplateStartPos

    /**
     * Determine the string representation of a byte element.
     * @param   in_bytId  The element as a byte.
     * @return  The element's start tag as a string.
     */
    public String resolveElementTag (byte in_bytId) throws J2WapException
    {
      switch (in_bytId)
      {
        case (byte) 0x1C: return WmlTags.START_TAG_A;
        case (byte) 0x1D: return WmlTags.START_TAG_TD;
        case (byte) 0x1E: return WmlTags.START_TAG_TR;
        case (byte) 0x1F: return WmlTags.START_TAG_TABLE;
        case (byte) 0x20: return WmlTags.START_TAG_P;
        case (byte) 0x21: return WmlTags.START_TAG_POSTFIELD;
        case (byte) 0x22: return WmlTags.START_TAG_ANCHOR;
        case (byte) 0x23: return WmlTags.START_TAG_ACCESS;
        case (byte) 0x24: return WmlTags.START_TAG_B;
        case (byte) 0x25: return WmlTags.START_TAG_BIG;
        case (byte) 0x26: return WmlTags.START_TAG_BR;
        case (byte) 0x27: return WmlTags.START_TAG_CARD;
        case (byte) 0x28: return WmlTags.START_TAG_DO;
        case (byte) 0x29: return WmlTags.START_TAG_EM;
        case (byte) 0x2A: return WmlTags.START_TAG_FIELDSET;
        case (byte) 0x2B: return WmlTags.START_TAG_GO;
        case (byte) 0x2C: return WmlTags.START_TAG_HEAD;
        case (byte) 0x2D: return WmlTags.START_TAG_I;
        case (byte) 0x2E: return WmlTags.START_TAG_IMG;
        case (byte) 0x2F: return WmlTags.START_TAG_INPUT;
        case (byte) 0x30: return WmlTags.START_TAG_META;
        case (byte) 0x31: return WmlTags.START_TAG_NOOP;
        case (byte) 0x32: return WmlTags.START_TAG_PREV;
        case (byte) 0x33: return WmlTags.START_TAG_ONEVENT;
        case (byte) 0x34: return WmlTags.START_TAG_OPTGROUP;
        case (byte) 0x35: return WmlTags.START_TAG_OPTION;
        case (byte) 0x36: return WmlTags.START_TAG_REFRESH;
        case (byte) 0x37: return WmlTags.START_TAG_SELECT;
        case (byte) 0x38: return WmlTags.START_TAG_SMALL;
        case (byte) 0x39: return WmlTags.START_TAG_STRONG;
        // No 0x3A tag.
        case (byte) 0x3B: return WmlTags.START_TAG_TEMPLATE;
        case (byte) 0x3C: return WmlTags.START_TAG_TIMER;
        case (byte) 0x3D: return WmlTags.START_TAG_U;
        case (byte) 0x3E: return WmlTags.START_TAG_SETVAR;
        case (byte) 0x3F: return WmlTags.START_TAG_WML;
        default: // Illegal tag. Raise an exception.
          J2WapException clsExcep = new J2WapException (
            "Error: Illegal tag (" + in_bytId + ").");
          throw (clsExcep);
      } // switch
    } // resolveElementTag

    /**
     * Determine the string representation of a byte element's end tag. Note
     * that this end tag is not a WML tag. These end tags are used to simplify
     * the work that the user interface must do to render the card.
     * @param   in_bytId  The element as a byte.
     * @return  The element's end tag as a string.
     */
    public String resolveEndTag (byte in_bytId) throws J2WapException
    {
      switch (in_bytId)
      {
        case (byte) 0x1C: return WmlTags.END_TAG_A;
        case (byte) 0x1D: return WmlTags.END_TAG_TD;
        case (byte) 0x1E: return WmlTags.END_TAG_TR;
        case (byte) 0x1F: return WmlTags.END_TAG_TABLE;
        case (byte) 0x20: return WmlTags.END_TAG_P;
        case (byte) 0x21: return WmlTags.END_TAG_POSTFIELD;
        case (byte) 0x22: return WmlTags.END_TAG_ANCHOR;
        case (byte) 0x23: return WmlTags.END_TAG_ACCESS;
        case (byte) 0x24: return WmlTags.END_TAG_B;
        case (byte) 0x25: return WmlTags.END_TAG_BIG;
        case (byte) 0x26: return WmlTags.END_TAG_BR;
        case (byte) 0x27: return WmlTags.END_TAG_CARD;
        case (byte) 0x28: return WmlTags.END_TAG_DO;
        case (byte) 0x29: return WmlTags.END_TAG_EM;
        case (byte) 0x2A: return WmlTags.END_TAG_FIELDSET;
        case (byte) 0x2B: return WmlTags.END_TAG_GO;
        case (byte) 0x2C: return WmlTags.END_TAG_HEAD;
        case (byte) 0x2D: return WmlTags.END_TAG_I;
        case (byte) 0x2E: return WmlTags.END_TAG_IMG;
        case (byte) 0x2F: return WmlTags.END_TAG_INPUT;
        case (byte) 0x30: return WmlTags.END_TAG_META;
        case (byte) 0x31: return WmlTags.END_TAG_NOOP;
        case (byte) 0x32: return WmlTags.END_TAG_PREV;
        case (byte) 0x33: return WmlTags.END_TAG_ONEVENT;
        case (byte) 0x34: return WmlTags.END_TAG_OPTGROUP;
        case (byte) 0x35: return WmlTags.END_TAG_OPTION;
        case (byte) 0x36: return WmlTags.END_TAG_REFRESH;
        case (byte) 0x37: return WmlTags.END_TAG_SELECT;
        case (byte) 0x38: return WmlTags.END_TAG_SMALL;
        case (byte) 0x39: return WmlTags.END_TAG_STRONG;
        // No 0x3A tag.
        case (byte) 0x3B: return WmlTags.END_TAG_TEMPLATE;
        case (byte) 0x3C: return WmlTags.END_TAG_TIMER;
        case (byte) 0x3D: return WmlTags.END_TAG_U;
        case (byte) 0x3E: return WmlTags.END_TAG_SETVAR;
        case (byte) 0x3F: return WmlTags.END_TAG_WML;
        default:  // Illegal attribrute start token. Raise an exception.
          J2WapException clsExcep = new J2WapException (
            "Error: Illegal attribrute start token (" + in_bytId + ").");
          throw (clsExcep);
      } // switch
    } // resolveEndTag

    /**
     * Determine the string representation of an byte attribute start token.
     * @param   in_bytId  The attribute start token as a byte.
     * @return  The attribute start token as a string.
     */
    public String resolveAttrStartToken (byte in_bytId) throws J2WapException
    {
      switch (in_bytId)
      {
        case (byte) 0x05: return "accept-charset";
        case (byte) 0x06: return "align=bottom";
        case (byte) 0x07: return "align=center";
        case (byte) 0x08: return "align=left";
        case (byte) 0x09: return "align=middle";
        case (byte) 0x0A: return "align=right";
        case (byte) 0x0B: return "align=top";