xmlwriter.java

基于Jabber协议的即时消息服务器

        writer.write( ";" );

        lastOutputNodeType = Node.ENTITY_REFERENCE_NODE;
    }

    protected void writeComment(String text) throws IOException {
        if (format.isNewlines()) {
            println();
            indent();
        }
        writer.write( "<!--" );
        writer.write( text );
        writer.write( "-->" );

        lastOutputNodeType = Node.COMMENT_NODE;
    }

    /** Writes the attributes of the given element
      *
      */
    protected void writeAttributes( Element element ) throws IOException {

        // I do not yet handle the case where the same prefix maps to
        // two different URIs. For attributes on the same element
        // this is illegal; but as yet we don't throw an exception
        // if someone tries to do this
        for ( int i = 0, size = element.attributeCount(); i < size; i++ ) {
            Attribute attribute = element.attribute(i);
            Namespace ns = attribute.getNamespace();
            if (ns != null && ns != Namespace.NO_NAMESPACE && ns != Namespace.XML_NAMESPACE) {
                String prefix = ns.getPrefix();
                String uri = namespaceStack.getURI(prefix);
                if (!ns.getURI().equals(uri)) { // output a new namespace declaration
                    writeNamespace(ns);
                    namespaceStack.push(ns);
                }
            }

            // If the attribute is a namespace declaration, check if we have already
            // written that declaration elsewhere (if that's the case, it must be
            // in the namespace stack
            String attName = attribute.getName();
            if (attName.startsWith("xmlns:")) {
                String prefix = attName.substring(6);
                if (namespaceStack.getNamespaceForPrefix(prefix) == null) {
                    String uri = attribute.getValue();
                    namespaceStack.push(prefix, uri);
                    writeNamespace(prefix, uri);
                }
            } else if (attName.equals("xmlns")) {
                if (namespaceStack.getDefaultNamespace() == null) {
                    String uri = attribute.getValue();
                    namespaceStack.push(null, uri);
                    writeNamespace(null, uri);
                }
            } else {
                char quote = format.getAttributeQuoteCharacter();
                writer.write(" ");
                writer.write(attribute.getQualifiedName());
                writer.write("=");
                writer.write(quote);
                writeEscapeAttributeEntities(attribute.getValue());
                writer.write(quote);
            }
        }
    }

    protected void writeAttribute(Attribute attribute) throws IOException {
        writer.write(" ");
        writer.write(attribute.getQualifiedName());
        writer.write("=");

        char quote = format.getAttributeQuoteCharacter();
        writer.write(quote);

        writeEscapeAttributeEntities(attribute.getValue());

        writer.write(quote);
        lastOutputNodeType = Node.ATTRIBUTE_NODE;
    }

    protected void writeAttributes(Attributes attributes) throws IOException {
        for (int i = 0, size = attributes.getLength(); i < size; i++) {
            writeAttribute( attributes, i );
        }
    }

    protected void writeAttribute(Attributes attributes, int index) throws IOException {
        char quote = format.getAttributeQuoteCharacter();
        writer.write(" ");
        writer.write(attributes.getQName(index));
        writer.write("=");
        writer.write(quote);
        writeEscapeAttributeEntities(attributes.getValue(index));
        writer.write(quote);
    }



    protected void indent() throws IOException {
        String indent = format.getIndent();
        if ( indent != null && indent.length() > 0 ) {
            for ( int i = 0; i < indentLevel; i++ ) {
                writer.write(indent);
            }
        }
    }

    /**
     * <p>
     * This will print a new line only if the newlines flag was set to true
     * </p>
     */
    protected void writePrintln() throws IOException  {
        if (format.isNewlines()) {
            writer.write( format.getLineSeparator() );
        }
    }

    /**
     * Get an OutputStreamWriter, use preferred encoding.
     */
    protected Writer createWriter(OutputStream outStream, String encoding) throws UnsupportedEncodingException {
        return new BufferedWriter(
            new OutputStreamWriter( outStream, encoding )
        );
    }

    /**
     * <p>
     * This will write the declaration to the given Writer.
     *   Assumes XML version 1.0 since we don't directly know.
     * </p>
     */
    protected void writeDeclaration() throws IOException {
        String encoding = format.getEncoding();

        // Only print of declaration is not suppressed
        if (! format.isSuppressDeclaration()) {
            // Assume 1.0 version
            if (encoding.equals("UTF8")) {
                writer.write("<?xml version=\"1.0\"");
                if (!format.isOmitEncoding()) {
                    writer.write(" encoding=\"UTF-8\"");
                }
                writer.write("?>");
            } else {
                writer.write("<?xml version=\"1.0\"");
                if (! format.isOmitEncoding()) {
                    writer.write(" encoding=\"" + encoding + "\"");
                }
                writer.write("?>");
            }
            if (format.isNewLineAfterDeclaration()) {
                println();
            }
        }
    }

    protected void writeClose(String qualifiedName) throws IOException {
        writer.write("</");
        writer.write(qualifiedName);
        writer.write(">");
    }

    protected void writeEmptyElementClose(String qualifiedName) throws IOException {
        // Simply close up
        if (! format.isExpandEmptyElements()) {
            writer.write("/>");
        } else {
            writer.write("></");
            writer.write(qualifiedName);
            writer.write(">");
        }
    }

    protected boolean isExpandEmptyElements() {
        return format.isExpandEmptyElements();
    }


    /** This will take the pre-defined entities in XML 1.0 and
      * convert their character representation to the appropriate
      * entity reference, suitable for XML attributes.
      */
    protected String escapeElementEntities(String text) {
        char[] block = null;
        int i, last = 0, size = text.length();
        for ( i = 0; i < size; i++ ) {
            String entity = null;
            char c = text.charAt(i);
            switch( c ) {
                case '<' :
                    entity = "&lt;";
                    break;
                case '>' :
                    entity = "&gt;";
                    break;
                case '&' :
                    entity = "&amp;";
                    break;
                case '\t': case '\n': case '\r':
                    // don't encode standard whitespace characters
                    if (preserve) {
                      entity=String.valueOf(c);
                    }
                    break;
                default:
                	if (c < 32 || shouldEncodeChar(c)) {
                        entity = "&#" + (int) c + ";";
                	}
                    break;
            }
            if (entity != null) {
                if ( block == null ) {
                    block = text.toCharArray();
                }
                buffer.append(block, last, i - last);
                buffer.append(entity);
                last = i + 1;
            }
        }
        if ( last == 0 ) {
            return text;
        }
        if ( last < size ) {
            if ( block == null ) {
                block = text.toCharArray();
            }
            buffer.append(block, last, i - last);
        }
        String answer = buffer.toString();
        buffer.setLength(0);
        return answer;
    }


    protected void writeEscapeAttributeEntities(String text) throws IOException {
        if ( text != null ) {
            String escapedText = escapeAttributeEntities( text );
            writer.write( escapedText );
        }
    }
    /** This will take the pre-defined entities in XML 1.0 and
      * convert their character representation to the appropriate
      * entity reference, suitable for XML attributes.
      */
    protected String escapeAttributeEntities(String text) {
        char quote = format.getAttributeQuoteCharacter();

        char[] block = null;
        int i, last = 0, size = text.length();
        for ( i = 0; i < size; i++ ) {
            String entity = null;
            char c = text.charAt(i);
            switch( c ) {
                case '<' :
                    entity = "&lt;";
                    break;
                case '>' :
                    entity = "&gt;";
                    break;
                case '\'' :
                    if (quote == '\'') {
                        entity = "&apos;";
                    }
                    break;
                case '\"' :
                    if (quote == '\"') {
                        entity = "&quot;";
                    }
                    break;
                case '&' :
                    entity = "&amp;";
                    break;
                case '\t': case '\n': case '\r':
                    // don't encode standard whitespace characters
                    break;
                default:
                	if (c < 32 || shouldEncodeChar(c)) {
                        entity = "&#" + (int) c + ";";
                	}
                    break;
            }
            if (entity != null) {
                if ( block == null ) {
                    block = text.toCharArray();
                }
                buffer.append(block, last, i - last);
                buffer.append(entity);
                last = i + 1;
            }
        }
        if ( last == 0 ) {
            return text;
        }
        if ( last < size ) {
            if ( block == null ) {
                block = text.toCharArray();
            }
            buffer.append(block, last, i - last);
        }
        String answer = buffer.toString();
        buffer.setLength(0);
        return answer;
    }

	/**
	 * Should the given character be escaped. This depends on the
	 * encoding of the document.
	 *
	 * @return boolean
	 */
	protected boolean shouldEncodeChar(char c) {
		int max = getMaximumAllowedCharacter();
		return max > 0 && c > max;
	}

	/**
	 * Returns the maximum allowed character code that should be allowed
	 * unescaped which defaults to 127 in US-ASCII (7 bit) or
	 * 255 in ISO-* (8 bit).
	 */
	protected int defaultMaximumAllowedCharacter() {
		String encoding = format.getEncoding();
		if (encoding != null) {
			if (encoding.equals("US-ASCII")) {
				return 127;
			}
		}
		// no encoding for things like ISO-*, UTF-8 or UTF-16
		return -1;
	}

    protected boolean isNamespaceDeclaration( Namespace ns ) {
        if (ns != null && ns != Namespace.XML_NAMESPACE) {
            String uri = ns.getURI();
            if ( uri != null ) {
                if ( ! namespaceStack.contains( ns ) ) {
                    return true;

                }
            }
        }
        return false;

    }

    protected void handleException(IOException e) throws SAXException {
        throw new SAXException(e);
    }

    //Laramie Crocker 4/8/2002 10:38AM
    /** Lets subclasses get at the current format object, so they can call setTrimText, setNewLines, etc.
      * Put in to support the HTMLWriter, in the way
      *  that it pushes the current newline/trim state onto a stack and overrides
      *  the state within preformatted tags.
      */
    protected OutputFormat getOutputFormat() {
        return format;
    }

    public boolean resolveEntityRefs() {
        return resolveEntityRefs;
    }

    public void setResolveEntityRefs(boolean resolve) {
        this.resolveEntityRefs = resolve;
    }
}