xmloutputter.java

一个用于搜索本地文件内容的小型搜索引擎

    /**
     * This will print indents only if indent is not null or the empty string.
     *
     * @param out <code>Writer</code> to use
     * @param level current indent level
     */
    private void indent(Writer out, int level) throws IOException {
        if (currentFormat.indent == null ||
            currentFormat.indent.equals("")) {
            return;
        }

        for (int i = 0; i < level; i++) {
            out.write(currentFormat.indent);
        }
    }

    // Returns the index of the first non-all-whitespace CDATA or Text,
    // index = content.size() is returned if content contains
    // all whitespace.
    // @param start index to begin search (inclusive)
    private int skipLeadingWhite(List content, int start) {
        if (start < 0) {
            start = 0;
        }

        int index = start;
        int size = content.size();
        if (currentFormat.mode == Format.TextMode.TRIM_FULL_WHITE
                || currentFormat.mode == Format.TextMode.NORMALIZE
                || currentFormat.mode == Format.TextMode.TRIM) {
            while (index < size) {
                if (!isAllWhitespace(content.get(index))) {
                    return index;
                }
                index++;
            }
        }
        return index;
    }

    // Return the index + 1 of the last non-all-whitespace CDATA or
    // Text node,  index < 0 is returned
    // if content contains all whitespace.
    // @param start index to begin search (exclusive)
    private int skipTrailingWhite(List content, int start) {
        int size = content.size();
        if (start > size) {
            start = size;
        }

        int index = start;
        if (currentFormat.mode == Format.TextMode.TRIM_FULL_WHITE
                || currentFormat.mode == Format.TextMode.NORMALIZE
                || currentFormat.mode == Format.TextMode.TRIM) {
            while (index >= 0) {
                if (!isAllWhitespace(content.get(index - 1)))
                    break;
                --index;
            }
        }
        return index;
    }

    // Return the next non-CDATA, non-Text, or non-EntityRef node,
    // index = content.size() is returned if there is no more non-CDATA,
    // non-Text, or non-EntiryRef nodes
    // @param start index to begin search (inclusive)
    private static int nextNonText(List content, int start) {
        if (start < 0) {
            start = 0;
        }

        int index = start;
        int size = content.size();
        while (index < size) {
            Object node =  content.get(index);
            if (!((node instanceof Text) || (node instanceof EntityRef))) {
                return index;
            }
            index++;
        }
        return size;
    }

    // Determine if a Object is all whitespace
    private boolean isAllWhitespace(Object obj) {
        String str = null;

        if (obj instanceof String) {
            str = (String) obj;
        }
        else if (obj instanceof Text) {
            str = ((Text) obj).getText();
        }
        else if (obj instanceof EntityRef) {
            return false;
        }
        else {
            return false;
        }

        for (int i = 0; i < str.length(); i++) {
            if (!Verifier.isXMLWhitespace(str.charAt(i)))
                return false;
        }
        return true;
    }

    // Determine if a string starts with a XML whitespace.
    private boolean startsWithWhite(String str) {
        if ((str != null) &&
            (str.length() > 0) &&
            Verifier.isXMLWhitespace(str.charAt(0))) {
           return true;
        }
        return false;
    }

    // Determine if a string ends with a XML whitespace.
    private boolean endsWithWhite(String str) {
        if ((str != null) &&
            (str.length() > 0) &&
            Verifier.isXMLWhitespace(str.charAt(str.length() - 1))) {
           return true;
        }
        return false;
    }

    /**
     * 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.  It does not convert
     * the single quote (') because it's not necessary as the outputter
     * writes attributes surrounded by double-quotes.
     *
     * @param str <code>String</code> input to escape.
     * @return <code>String</code> with escaped content.
     */
    public String escapeAttributeEntities(String str) {
        StringBuffer buffer;
        char ch;
        String entity;
        EscapeStrategy strategy = currentFormat.escapeStrategy;

        buffer = null;
        for (int i = 0; i < str.length(); i++) {
            ch = str.charAt(i);
            switch(ch) {
                case '<' :
                    entity = "&lt;";
                    break;
                case '>' :
                    entity = "&gt;";
                    break;
/*
                case '\'' :
                    entity = "&apos;";
                    break;
*/
                case '\"' :
                    entity = "&quot;";
                    break;
                case '&' :
                    entity = "&amp;";
                    break;
                case '\r' :
                    entity = "&#xD;";
                    break;
                case '\t' :
                    entity = "&#x9;";
                    break;
                case '\n' :
                    entity = "&#xA;";
                    break;
                default :
                    if (strategy.shouldEscape(ch)) {
                        entity = "&#x" + Integer.toHexString(ch) + ";";
                    }
                    else {
                        entity = null;
                    }
                    break;
            }
            if (buffer == null) {
                if (entity != null) {
                    // An entity occurred, so we'll have to use StringBuffer
                    // (allocate room for it plus a few more entities).
                    buffer = new StringBuffer(str.length() + 20);
                    // Copy previous skipped characters and fall through
                    // to pickup current character
                    buffer.append(str.substring(0, i));
                    buffer.append(entity);
                }
            }
            else {
                if (entity == null) {
                    buffer.append(ch);
                }
                else {
                    buffer.append(entity);
                }
            }
        }

        // If there were any entities, return the escaped characters
        // that we put in the StringBuffer. Otherwise, just return
        // the unmodified input string.
        return (buffer == null) ? str : buffer.toString();
    }


    /**
     * This will take the three pre-defined entities in XML 1.0
     * (used specifically in XML elements) and convert their character
     * representation to the appropriate entity reference, suitable for
     * XML element content.
     *
     * @param str <code>String</code> input to escape.
     * @return <code>String</code> with escaped content.
     */
    public String escapeElementEntities(String str) {
        if (escapeOutput == false) return str;

        StringBuffer buffer;
        char ch;
        String entity;
        EscapeStrategy strategy = currentFormat.escapeStrategy;

        buffer = null;
        for (int i = 0; i < str.length(); i++) {
            ch = str.charAt(i);
            switch(ch) {
                case '<' :
                    entity = "&lt;";
                    break;
                case '>' :
                    entity = "&gt;";
                    break;
                case '&' :
                    entity = "&amp;";
                    break;
                case '\r' :
                    entity = "&#xD;";
                    break;
                case '\n' :
                    entity = currentFormat.lineSeparator;
                    break;
                default :
                    if (strategy.shouldEscape(ch)) {
                        entity = "&#x" + Integer.toHexString(ch) + ";";
                    }
                    else {
                        entity = null;
                    }
                    break;
            }
            if (buffer == null) {
                if (entity != null) {
                    // An entity occurred, so we'll have to use StringBuffer
                    // (allocate room for it plus a few more entities).
                    buffer = new StringBuffer(str.length() + 20);
                    // Copy previous skipped characters and fall through
                    // to pickup current character
                    buffer.append(str.substring(0, i));
                    buffer.append(entity);
                }
            }
            else {
                if (entity == null) {
                    buffer.append(ch);
                }
                else {
                    buffer.append(entity);
                }
            }
        }

        // If there were any entities, return the escaped characters
        // that we put in the StringBuffer. Otherwise, just return
        // the unmodified input string.
        return (buffer == null) ? str : buffer.toString();
    }

    /**
     * Returns a copy of this XMLOutputter.
     */
    public Object clone() {
        // Implementation notes: Since all state of an XMLOutputter is
        // embodied in simple private instance variables, Object.clone
        // can be used.  Note that since Object.clone is totally
        // broken, we must catch an exception that will never be
        // thrown.
        try {
            return super.clone();
        }
        catch (java.lang.CloneNotSupportedException e) {
            // even though this should never ever happen, it's still
            // possible to fool Java into throwing a
            // CloneNotSupportedException.  If that happens, we
            // shouldn't swallow it.
            throw new RuntimeException(e.toString());
        }
    }

    /**
     * Return a string listing of the settings for this
     * XMLOutputter instance.
     *
     * @return a string listing the settings for this XMLOutputter instance
     */
    public String toString() {
        StringBuffer buffer = new StringBuffer();
        for (int i = 0; i < userFormat.lineSeparator.length(); i++) {
            char ch = userFormat.lineSeparator.charAt(i);
            switch (ch) {
            case '\r': buffer.append("\\r");
                       break;
            case '\n': buffer.append("\\n");
                       break;
            case '\t': buffer.append("\\t");
                       break;
            default:   buffer.append("[" + ((int)ch) + "]");
                       break;
            }
        }

        return (
            "XMLOutputter[omitDeclaration = " + userFormat.omitDeclaration + ", " +
            "encoding = " + userFormat.encoding + ", " +
            "omitEncoding = " + userFormat.omitEncoding + ", " +
            "indent = '" + userFormat.indent + "'" + ", " +
            "expandEmptyElements = " + userFormat.expandEmptyElements + ", " +
            "lineSeparator = '" + buffer.toString() + "', " +
            "textMode = " + userFormat.mode + "]"
        );
    }

    /**
     * Factory for making new NamespaceStack objects.  The NamespaceStack
     * created is actually an inner class extending the package protected
     * NamespaceStack, as a way to make NamespaceStack "friendly" toward
     * subclassers.
     */
    private NamespaceStack createNamespaceStack() {
       // actually returns a XMLOutputter.NamespaceStack (see below)
       return new NamespaceStack();
    }

    /**
     * Our own null subclass of NamespaceStack.  This plays a little
     * trick with Java access protection.  We want subclasses of
     * XMLOutputter to be able to override protected methods that
     * declare a NamespaceStack parameter, but we don't want to
     * declare the parent NamespaceStack class as public.
     */
    protected class NamespaceStack
        extends org.jdom.output.NamespaceStack
    {
    }

    // Support method to print a name without using elt.getQualifiedName()
    // and thus avoiding a StringBuffer creation and memory churn
    private void printQualifiedName(Writer out, Element e) throws IOException {
        if (e.getNamespace().getPrefix().length() == 0) {
            out.write(e.getName());
        }
        else {
            out.write(e.getNamespace().getPrefix());
            out.write(':');
            out.write(e.getName());
        }
    }

    // Support method to print a name without using att.getQualifiedName()
    // and thus avoiding a StringBuffer creation and memory churn
    private void printQualifiedName(Writer out, Attribute a) throws IOException {
        String prefix = a.getNamespace().getPrefix();
        if ((prefix != null) && (!prefix.equals(""))) {
            out.write(prefix);
            out.write(':');
            out.write(a.getName());
        }
        else {
            out.write(a.getName());
        }
    }

    // * * * * * * * * * * Deprecated methods * * * * * * * * * *

    /* The methods below here are deprecations of protected methods.  We
     * don't usually deprecate protected methods, so they're commented out.
     * They're left here in case this mass deprecation causes people trouble.
     * Since we're getting close to 1.0 it's actually better for people to
     * raise issues early though.
     */

}