xmlparser.java

linux下建立JAVA虚拟机的源码KAFFE

   * @return true if whitespace characters were read, false otherwise
   */
  private boolean tryWhitespace()
    throws IOException, XMLStreamException
  {
    boolean white;
    boolean ret = false;
    do
      {
        mark(1);
        int c = readCh();
        while (c == -1 && inputStack.size() > 1)
          {
            popInput();
            c = readCh();
          }
        white = (c == 0x20 || c == 0x09 || c == 0x0a || c == 0x0d);
        if (white)
          ret = true;
      }
    while (white);
    reset();
    return ret;
  }

  /**
   * Skip over any whitespace characters.
   */
  private void skipWhitespace()
    throws IOException, XMLStreamException
  {
    boolean white;
    do
      {
        mark(1);
        int c = readCh();
        while (c == -1 && inputStack.size() > 1)
          {
            popInput();
            c = readCh();
          }
        white = (c == 0x20 || c == 0x09 || c == 0x0a || c == 0x0d);
      }
    while (white);
    reset();
  }

  /**
   * Try to read as many whitespace characters as are available.
   * @exception XMLStreamException if no whitespace characters were seen
   */
  private void requireWhitespace()
    throws IOException, XMLStreamException
  {
    if (!tryWhitespace())
      error("whitespace required");
  }

  /**
   * Returns the current base URI for resolving external entities.
   */
  String getXMLBase()
  {
    if (baseAware)
      {
        for (Iterator i = bases.iterator(); i.hasNext(); )
          {
            String base = (String) i.next();
            if (base != null)
              return base;
          }
      }
    return input.systemId;
  }

  /**
   * Push the specified text input source.
   */
  private void pushInput(String name, String text, boolean report,
                         boolean normalize)
    throws IOException, XMLStreamException
  {
    // Check for recursion
    if (name != null && !"".equals(name))
      {
        for (Iterator i = inputStack.iterator(); i.hasNext(); )
          {
            Input ctx = (Input) i.next();
            if (name.equals(ctx.name))
              error("entities may not be self-recursive", name);
          }
      }
    else
      report = false;
    pushInput(new Input(null, new StringReader(text), input.publicId,
                        input.systemId, name, input.inputEncoding, report,
                        normalize));
  }

  /**
   * Push the specified external input source.
   */
  private void pushInput(String name, ExternalIds ids, boolean report,
                         boolean normalize)
    throws IOException, XMLStreamException
  {
    if (!externalEntities)
      return;
    String url = absolutize(input.systemId, ids.systemId);
    // Check for recursion
    for (Iterator i = inputStack.iterator(); i.hasNext(); )
      {
        Input ctx = (Input) i.next();
        if (url.equals(ctx.systemId))
          error("entities may not be self-recursive", url);
        if (name != null && !"".equals(name) && name.equals(ctx.name))
          error("entities may not be self-recursive", name);
      }
    if (name == null || "".equals(name))
      report = false;
    InputStream in = null;
    if (resolver != null)
      {
        Object obj = resolver.resolveEntity(ids.publicId, url, getXMLBase(),
                                            null);
        if (obj instanceof InputStream)
          in = (InputStream) obj;
      }
    if (in == null)
      in = resolve(url);
    if (in == null)
      error("unable to resolve external entity",
            (ids.systemId != null) ? ids.systemId : ids.publicId);
    pushInput(new Input(in, null, ids.publicId, url, name, null, report,
                        normalize));
    input.init();
    if (tryRead(TEST_XML_DECL))
      readTextDecl();
    input.finalizeEncoding();
  }

  /**
   * Push the specified input source (general entity) onto the input stack.
   */
  private void pushInput(Input input)
  {
    if (input.report)
      startEntityStack.addFirst(input.name);
    inputStack.addLast(input);
    if (this.input != null)
      input.xml11 = this.input.xml11;
    this.input = input;
  }

  /**
   * "Absolutize" a URL. This resolves a relative URL into an absolute one.
   * @param base the current base URL
   * @param href the (absolute or relative) URL to resolve
   */
  public static String absolutize(String base, String href)
    throws MalformedURLException
  {
    if (href == null)
      return null;
    int ci = href.indexOf(':');
    if (ci > 1 && isURLScheme(href.substring(0, ci)))
      {
        // href is absolute already
        return href;
      }
    if (base == null)
      base = "";
    else
      {
        int i = base.lastIndexOf('/');
        if (i != -1)
          base = base.substring(0, i + 1);
        else
          base = "";
      }
    if ("".equals(base))
      {
        // assume file URL relative to current directory
        base = System.getProperty("user.dir");
        if (base.charAt(0) == '/')
          base = base.substring(1);
        base = "file:///" + base.replace(File.separatorChar, '/');
        if (!base.endsWith("/"))
          base += "/";
      }
    return new URL(new URL(base), href).toString();
  }

  /**
   * Indicates whether the specified characters match the scheme portion of
   * a URL.
   * @see RFC 1738 section 2.1
   */
  private static boolean isURLScheme(String text)
  {
    int len = text.length();
    for (int i = 0; i < len; i++)
      {
        char c = text.charAt(i);
        if (c == '+' || c == '.' || c == '-')
          continue;
        if (c < 65 || (c > 90 && c < 97) || c > 122)
          return false;
      }
    return true;
  }

  /**
   * Returns an input stream for the given URL.
   */
  static InputStream resolve(String url)
    throws IOException
  {
    try
      {
        return new URL(url).openStream();
      }
    catch (MalformedURLException e)
      {
        return null;
      }
    catch (IOException e)
      {
        IOException e2 = new IOException("error resolving " + url);
        e2.initCause(e);
        throw e2;
      }
  }

  /**
   * Pops the current input source (general entity) off the stack.
   */
  private void popInput()
  {
    Input old = (Input) inputStack.removeLast();
    if (old.report)
      endEntityStack.addFirst(old.name);
    input = (Input) inputStack.getLast();
  }

  /**
   * Parse an entity text declaration.
   */
  private void readTextDecl()
    throws IOException, XMLStreamException
  {
    final int flags = LIT_DISABLE_CREF | LIT_DISABLE_PE | LIT_DISABLE_EREF;
    requireWhitespace();
    if (tryRead("version"))
      {
        readEq();
        String v = readLiteral(flags, false);
        if ("1.0".equals(v))
          input.xml11 = false;
        else if ("1.1".equals(v))
          {
            Input i1 = (Input) inputStack.getFirst();
            if (!i1.xml11)
              error("external entity specifies later version number");
            input.xml11 = true;
          }
        else
          throw new XMLStreamException("illegal XML version: " + v);
        requireWhitespace();
      }
    require("encoding");
    readEq();
    String enc = readLiteral(flags, false);
    skipWhitespace();
    require("?>");
    input.setInputEncoding(enc);
  }

  /**
   * Parse the XML declaration.
   */
  private void readXMLDecl()
    throws IOException, XMLStreamException
  {
    final int flags = LIT_DISABLE_CREF | LIT_DISABLE_PE | LIT_DISABLE_EREF;
    
    requireWhitespace();
    require("version");
    readEq();
    xmlVersion = readLiteral(flags, false);
    if ("1.0".equals(xmlVersion))
      input.xml11 = false;
    else if ("1.1".equals(xmlVersion))
      input.xml11 = true;
    else
      throw new XMLStreamException("illegal XML version: " + xmlVersion);
    
    boolean white = tryWhitespace();
    
    if (tryRead("encoding"))
      {
        if (!white)
          error("whitespace required before 'encoding='");
        readEq();
        xmlEncoding = readLiteral(flags, false);
        white = tryWhitespace();
      }
    
    if (tryRead("standalone"))
      {
        if (!white)
          error("whitespace required before 'standalone='");
        readEq();
        String standalone = readLiteral(flags, false);
        if ("yes".equals(standalone))
          xmlStandalone = Boolean.TRUE;
        else if ("no".equals(standalone))
          xmlStandalone = Boolean.FALSE;
        else
          error("standalone flag must be 'yes' or 'no'", standalone);
      }

    skipWhitespace();
    require("?>");
    if (xmlEncoding != null)
      input.setInputEncoding(xmlEncoding);
  }

  /**
   * Parse the DOCTYPE declaration.
   */
  private void readDoctypeDecl()
    throws IOException, XMLStreamException
  {
    if (!supportDTD)
      error("parser was configured not to support DTDs");
    requireWhitespace();
    String rootName = readNmtoken(true);
    skipWhitespace();
    ExternalIds ids = readExternalIds(false, true);
    doctype =
      this.new Doctype(rootName, ids.publicId, ids.systemId);
    
    // Parse internal subset first
    skipWhitespace();
    if (tryRead('['))
      {
        while (true)
          {
            expandPE = true;
            skipWhitespace();
            expandPE = false;
            if (tryRead(']'))
              break;
            else
              readMarkupdecl(false);
          }
      }
    skipWhitespace();
    require('>');

    // Parse external subset
    if (ids.systemId != null && externalEntities)
      {
        pushInput("", ">", false, false);
        pushInput("[dtd]", ids, true, true);
        // loop until we get back to ">"
        while (true)
          {
            expandPE = true;
            skipWhitespace();
            expandPE = false;
            mark(1);
            int c = readCh();
            if (c == 0x3e) // '>'
              break;
            else if (c == -1)
              popInput();
            else
              {
                reset();
                expandPE = true;
                readMarkupdecl(true);
                expandPE = true;
              }
          }
        if (inputStack.size() != 2)
          error("external subset has unmatched '>'");
        popInput();
      }
    checkDoctype();
    if (validating)
      validateDoctype();

    // Make rootName available for reading
    buf.setLength(0);
    buf.append(rootName);
  }

  /**
   * Checks the well-formedness of the DTD.
   */
  private void checkDoctype()
    throws XMLStreamException
  {
    // TODO check entity recursion
  }

  /**
   * Parse the markupdecl production.
   */
  private void readMarkupdecl(boolean inExternalSubset)
    throws IOException, XMLStreamException
  {
    boolean saved = expandPE;
    mark(1);
    require('<');
    reset();
    expandPE = false;
    if (tryRead(TEST_ELEMENT_DECL))
      {
        expandPE = saved;
        readElementDecl();
      }
    else if (tryRead(TEST_ATTLIST_DECL))
      {
        expandPE = saved;
        readAttlistDecl();
      }
    else if (tryRead(TEST_ENTITY_DECL))
      {
        expandPE = saved;
        readEntityDecl(inExternalSubset);
      }
    else if (tryRead(TEST_NOTATION_DECL))
      {
        expandPE = saved;
        readNotationDecl(inExternalSubset);
      }
    else if (tryRead(TEST_PI))
      {
        readPI(true);
        expandPE = saved;
      }
    else if (tryRead(TEST_COMMENT))
      {
        readComment(true);
        expandPE = saved;
      }
    else if (tryRead("<!["))
      {
        // conditional section
        expandPE = saved;
        if (inputStack.size() < 2)
          error("conditional sections illegal in internal subset");
        skipWhitespace();
        if (tryRead("INCLUDE"))
          {
            skipWhitespace();
            require('[');
            skipWhitespace();
            while (!tryRead("]]>"))
              {
                readMarkupdecl(inExternalSubset);