node.java

业界著名的tomcat服务器的最新6.0的源代码。

            return result;
        }

        public void setUseTagPlugin(boolean use) {
            useTagPlugin = use;
        }

        public boolean useTagPlugin() {
            return useTagPlugin;
        }

        public void setTagPluginContext(TagPluginContext tagPluginContext) {
            this.tagPluginContext = tagPluginContext;
        }

        public TagPluginContext getTagPluginContext() {
            return tagPluginContext;
        }

        public void setAtSTag(Nodes sTag) {
            atSTag = sTag;
        }

        public Nodes getAtSTag() {
            return atSTag;
        }

        public void setAtETag(Nodes eTag) {
            atETag = eTag;
        }

        public Nodes getAtETag() {
            return atETag;
        }

        /*
         * Computes this custom tag's custom nesting level, which corresponds to
         * the number of times this custom tag is nested inside itself.
         * 
         * Example:
         * 
         * <g:h> <a:b> -- nesting level 0 <c:d> <e:f> <a:b> -- nesting level 1
         * <a:b> -- nesting level 2 </a:b> </a:b> <a:b> -- nesting level 1
         * </a:b> </e:f> </c:d> </a:b> </g:h>
         * 
         * @return Custom tag's nesting level
         */
        private int makeCustomNestingLevel() {
            int n = 0;
            Node p = parent;
            while (p != null) {
                if ((p instanceof Node.CustomTag)
                        && qName.equals(((Node.CustomTag) p).qName)) {
                    n++;
                }
                p = p.parent;
            }
            return n;
        }

        /**
         * Returns true if this custom action has an empty body, and false
         * otherwise.
         * 
         * A custom action is considered to have an empty body if the following
         * holds true: - getBody() returns null, or - all immediate children are
         * jsp:attribute actions, or - the action's jsp:body is empty.
         */
        public boolean hasEmptyBody() {
            boolean hasEmptyBody = true;
            Nodes nodes = getBody();
            if (nodes != null) {
                int numChildNodes = nodes.size();
                for (int i = 0; i < numChildNodes; i++) {
                    Node n = nodes.getNode(i);
                    if (!(n instanceof NamedAttribute)) {
                        if (n instanceof JspBody) {
                            hasEmptyBody = (n.getBody() == null);
                        } else {
                            hasEmptyBody = false;
                        }
                        break;
                    }
                }
            }

            return hasEmptyBody;
        }
    }

    /**
     * Used as a placeholder for the evaluation code of a custom action
     * attribute (used by the tag plugin machinery only).
     */
    public static class AttributeGenerator extends Node {
        String name; // name of the attribute

        CustomTag tag; // The tag this attribute belongs to

        public AttributeGenerator(Mark start, String name, CustomTag tag) {
            super(start, null);
            this.name = name;
            this.tag = tag;
        }

        public void accept(Visitor v) throws JasperException {
            v.visit(this);
        }

        public String getName() {
            return name;
        }

        public CustomTag getTag() {
            return tag;
        }
    }

    /**
     * Represents the body of a &lt;jsp:text&gt; element
     */
    public static class JspText extends Node {

        public JspText(String qName, Attributes nonTaglibXmlnsAttrs,
                Attributes taglibAttrs, Mark start, Node parent) {
            super(qName, TEXT_ACTION, null, nonTaglibXmlnsAttrs, taglibAttrs,
                    start, parent);
        }

        public void accept(Visitor v) throws JasperException {
            v.visit(this);
        }
    }

    /**
     * Represents a Named Attribute (&lt;jsp:attribute&gt;)
     */
    public static class NamedAttribute extends Node {

        // A unique temporary variable name suitable for code generation
        private String temporaryVariableName;

        // True if this node is to be trimmed, or false otherwise
        private boolean trim = true;

        private ChildInfo childInfo;

        private String name;

        private String localName;

        private String prefix;

        public NamedAttribute(Attributes attrs, Mark start, Node parent) {
            this(JSP_ATTRIBUTE_ACTION, attrs, null, null, start, parent);
        }

        public NamedAttribute(String qName, Attributes attrs,
                Attributes nonTaglibXmlnsAttrs, Attributes taglibAttrs,
                Mark start, Node parent) {

            super(qName, ATTRIBUTE_ACTION, attrs, nonTaglibXmlnsAttrs,
                    taglibAttrs, start, parent);
            temporaryVariableName = JspUtil.nextTemporaryVariableName();
            if ("false".equals(this.getAttributeValue("trim"))) {
                // (if null or true, leave default of true)
                trim = false;
            }
            childInfo = new ChildInfo();
            name = this.getAttributeValue("name");
            if (name != null) {
                // Mandatary attribute "name" will be checked in Validator
                localName = name;
                int index = name.indexOf(':');
                if (index != -1) {
                    prefix = name.substring(0, index);
                    localName = name.substring(index + 1);
                }
            }
        }

        public void accept(Visitor v) throws JasperException {
            v.visit(this);
        }

        public String getName() {
            return this.name;
        }

        public String getLocalName() {
            return this.localName;
        }

        public String getPrefix() {
            return this.prefix;
        }

        public ChildInfo getChildInfo() {
            return this.childInfo;
        }

        public boolean isTrim() {
            return trim;
        }

        /**
         * @return A unique temporary variable name to store the result in.
         *         (this probably could go elsewhere, but it's convenient here)
         */
        public String getTemporaryVariableName() {
            return temporaryVariableName;
        }

        /*
         * Get the attribute value from this named attribute (<jsp:attribute>).
         * Since this method is only for attributes that are not rtexpr, we can
         * assume the body of the jsp:attribute is a template text.
         */
        public String getText() {

            class AttributeVisitor extends Visitor {
                String attrValue = null;

                public void visit(TemplateText txt) {
                    attrValue = new String(txt.getText());
                }

                public String getAttrValue() {
                    return attrValue;
                }
            }

            // According to JSP 2.0, if the body of the <jsp:attribute>
            // action is empty, it is equivalent of specifying "" as the value
            // of the attribute.
            String text = "";
            if (getBody() != null) {
                AttributeVisitor attributeVisitor = new AttributeVisitor();
                try {
                    getBody().visit(attributeVisitor);
                } catch (JasperException e) {
                }
                text = attributeVisitor.getAttrValue();
            }

            return text;
        }
    }

    /**
     * Represents a JspBody node (&lt;jsp:body&gt;)
     */
    public static class JspBody extends Node {

        private ChildInfo childInfo;

        public JspBody(Mark start, Node parent) {
            this(JSP_BODY_ACTION, null, null, start, parent);
        }

        public JspBody(String qName, Attributes nonTaglibXmlnsAttrs,
                Attributes taglibAttrs, Mark start, Node parent) {
            super(qName, BODY_ACTION, null, nonTaglibXmlnsAttrs, taglibAttrs,
                    start, parent);
            this.childInfo = new ChildInfo();
        }

        public void accept(Visitor v) throws JasperException {
            v.visit(this);
        }

        public ChildInfo getChildInfo() {
            return childInfo;
        }
    }

    /**
     * Represents a template text string
     */
    public static class TemplateText extends Node {

        private ArrayList extraSmap = null;

        public TemplateText(String text, Mark start, Node parent) {
            super(null, null, text, start, parent);
        }

        public void accept(Visitor v) throws JasperException {
            v.visit(this);
        }

        /**
         * Trim all whitespace from the left of the template text
         */
        public void ltrim() {
            int index = 0;
            while ((index < text.length()) && (text.charAt(index) <= ' ')) {
                index++;
            }
            text = text.substring(index);
        }

        public void setText(String text) {
            this.text = text;
        }

        /**
         * Trim all whitespace from the right of the template text
         */
        public void rtrim() {
            int index = text.length();
            while ((index > 0) && (text.charAt(index - 1) <= ' ')) {
                index--;
            }
            text = text.substring(0, index);
        }

        /**
         * Returns true if this template text contains whitespace only.
         */
        public boolean isAllSpace() {
            boolean isAllSpace = true;
            for (int i = 0; i < text.length(); i++) {
                if (!Character.isWhitespace(text.charAt(i))) {
                    isAllSpace = false;
                    break;
                }
            }
            return isAllSpace;
        }

        /**
         * Add a source to Java line mapping
         * 
         * @param srcLine
         *            The postion of the source line, relative to the line at
         *            the start of this node. The corresponding java line is
         *            assumed to be consecutive, i.e. one more than the last.
         */
        public void addSmap(int srcLine) {
            if (extraSmap == null) {
                extraSmap = new ArrayList();
            }
            extraSmap.add(new Integer(srcLine));
        }

        public ArrayList getExtraSmap() {
            return extraSmap;
        }
    }

    /***************************************************************************
     * Auxillary classes used in Node
     */

    /**
     * Represents attributes that can be request time expressions.
     * 
     * Can either be a plain attribute, an attribute that represents a request
     * time expression value, or a named attribute (specified using the
     * jsp:attribute standard action).
     */

    public static class JspAttribute {

        private String qName;

        private String uri;

        private String localName;

        private String value;

        private boolean expression;

        private boolean dynamic;

        private final ELNode.Nodes el;

        private final TagAttributeInfo tai;

        // If true, this JspAttribute represents a <jsp:attribute>
        private boolean namedAttribute;

        // The node in the parse tree for the NamedAttribute
        private NamedAttribute namedAttributeNode;

        JspAttribute(TagAttributeInfo tai, String qName, String uri,
                String localName, String value, boolean expr, ELNode.Nodes el,
                boolean dyn) {
            this.qName = qName;
            this.uri = uri;
            this.localName = localName;
            this.value = value;
            this.namedAttributeNode = null;
            this.expression = expr;
            this.el = el;
            this.dynamic = dyn;
            this.namedAttribute = false;
            this.tai = tai;
        }

        /**
         * Allow node to validate itself
         * 
         * @param ef
         * @param ctx
         * @throws ELException
         */
        public void validateEL(ExpressionFactory ef, ELContext ctx)
                throws ELException {
            if (this.el != null) {
                // determine exact type
                ValueExpression ve = ef.createValueExpression(ctx, this.value,
                        String.class);
            }
        }

        /**
         * Use this constructor if the JspAttribute represents a named
         * attribute. In this case, we have to store the nodes of the body of
         * the attribute.
         */
        JspAttribute(NamedAttribute na, TagAttributeInf