validator.java

业界著名的tomcat服务器的最新6.0的源代码。

                                        err.jspError
                                            (n, "jsp.error.coerce_to_type",
                                             tldAttrs[j].getName(), expectedType, attrs.getValue(i));
                                    }
                                }

                                jspAttrs[i] = new Node.JspAttribute(tldAttrs[j],
                                        attrs.getQName(i), attrs.getURI(i), attrs
                                                .getLocalName(i),
                                        attrs.getValue(i), false, null, false);
                            } else {
                                
                                if (deferred && !tldAttrs[j].isDeferredMethod() && !tldAttrs[j].isDeferredValue()) {
                                    // No deferred expressions allowed for this attribute
                                    err.jspError(n, "jsp.error.attribute.custom.non_rt_with_expr",
                                            tldAttrs[j].getName());
                                }
                                if (!deferred && !tldAttrs[j].canBeRequestTime()) {
                                    // Only deferred expressions are allowed for this attribute
                                    err.jspError(n, "jsp.error.attribute.custom.non_rt_with_expr",
                                            tldAttrs[j].getName());
                                }
                                
                                Class expectedType = String.class;
                                try {
                                    String typeStr = tldAttrs[j].getTypeName();
                                    if (tldAttrs[j].isFragment()) {
                                        expectedType = JspFragment.class;
                                    } else if (typeStr != null) {
                                        expectedType = JspUtil.toClass(typeStr,
                                                loader);
                                    }
                                    if (elExpression) {
                                        // El expression
                                        validateFunctions(el, n);
                                        jspAttrs[i] = new Node.JspAttribute(tldAttrs[j],
                                                attrs.getQName(i), attrs.getURI(i), 
                                                attrs.getLocalName(i),
                                                attrs.getValue(i), false, el, false);
                                        ELContextImpl ctx = new ELContextImpl();
                                        ctx.setFunctionMapper(getFunctionMapper(el));
                                        try {
                                            jspAttrs[i].validateEL(this.pageInfo.getExpressionFactory(), ctx);
                                        } catch (ELException e) {
                                            this.err.jspError(n.getStart(),
                                                    "jsp.error.invalid.expression", 
                                                    attrs.getValue(i), e.toString());
                                        }
                                    } else {
                                        // Runtime expression
                                        jspAttrs[i] = getJspAttribute(tldAttrs[j],
                                                attrs.getQName(i), attrs.getURI(i),
                                                attrs.getLocalName(i), attrs
                                                .getValue(i), expectedType, n,
                                                false);
                                    }
                                } catch (ClassNotFoundException e) {
                                    err.jspError
                                        (n, "jsp.error.unknown_attribute_type",
                                         tldAttrs[j].getName(), tldAttrs[j].getTypeName());
                                }
                            }
                            
                        } else {
                            // Attribute does not accept any expressions.
                            // Make sure its value does not contain any.
                            if (expression) {
                                err.jspError(n, "jsp.error.attribute.custom.non_rt_with_expr",
                                                tldAttrs[j].getName());
                            }
                            jspAttrs[i] = new Node.JspAttribute(tldAttrs[j],
                                    attrs.getQName(i), attrs.getURI(i), attrs
                                            .getLocalName(i),
                                    attrs.getValue(i), false, null, false);
                        }
                        if (jspAttrs[i].isExpression()) {
                            tagDataAttrs.put(attrs.getQName(i),
                                    TagData.REQUEST_TIME_VALUE);
                        } else {
                            tagDataAttrs.put(attrs.getQName(i), attrs
                                    .getValue(i));
                        }
                        found = true;
                        break;
                    }
                }
                if (!found) {
                    if (tagInfo.hasDynamicAttributes()) {
                        jspAttrs[i] = getJspAttribute(null, attrs.getQName(i),
                                attrs.getURI(i), attrs.getLocalName(i), attrs
                                        .getValue(i), java.lang.Object.class,
                                n, true);
                    } else {
                        err.jspError(n, "jsp.error.bad_attribute", attrs
                                .getQName(i), n.getLocalName());
                    }
                }
            }
        }

        /*
         * Make sure the given custom action does not have any invalid named
         * attributes
         */
        private void checkNamedAttributes(Node.CustomTag n,
                Node.JspAttribute[] jspAttrs, int start, 
                Hashtable<String, Object> tagDataAttrs)
                throws JasperException {

            TagInfo tagInfo = n.getTagInfo();
            if (tagInfo == null) {
                err.jspError(n, "jsp.error.missing.tagInfo", n.getQName());
            }
            TagAttributeInfo[] tldAttrs = tagInfo.getAttributes();
            Node.Nodes naNodes = n.getNamedAttributeNodes();

            for (int i = 0; i < naNodes.size(); i++) {
                Node.NamedAttribute na = (Node.NamedAttribute) naNodes
                        .getNode(i);
                boolean found = false;
                for (int j = 0; j < tldAttrs.length; j++) {
                    /*
                     * See above comment about namespace matches. For named
                     * attributes, we use the prefix instead of URI as the match
                     * criterion, because in the case of a JSP document, we'd
                     * have to keep track of which namespaces are in scope when
                     * parsing a named attribute, in order to determine the URI
                     * that the prefix of the named attribute's name matches to.
                     */
                    String attrPrefix = na.getPrefix();
                    if (na.getLocalName().equals(tldAttrs[j].getName())
                            && (attrPrefix == null || attrPrefix.length() == 0 || attrPrefix
                                    .equals(n.getPrefix()))) {
                        jspAttrs[start + i] = new Node.JspAttribute(na,
                                tldAttrs[j], false);
                        NamedAttributeVisitor nav = null;
                        if (na.getBody() != null) {
                            nav = new NamedAttributeVisitor();
                            na.getBody().visit(nav);
                        }
                        if (nav != null && nav.hasDynamicContent()) {
                            tagDataAttrs.put(na.getName(),
                                    TagData.REQUEST_TIME_VALUE);
                        } else {
                            tagDataAttrs.put(na.getName(), na.getText());
                        }
                        found = true;
                        break;
                    }
                }
                if (!found) {
                    if (tagInfo.hasDynamicAttributes()) {
                        jspAttrs[start + i] = new Node.JspAttribute(na, null,
                                true);
                    } else {
                        err.jspError(n, "jsp.error.bad_attribute",
                                na.getName(), n.getLocalName());
                    }
                }
            }
        }

        /**
         * Preprocess attributes that can be expressions. Expression delimiters
         * are stripped.
         * <p>
         * If value is null, checks if there are any NamedAttribute subelements
         * in the tree node, and if so, constructs a JspAttribute out of a child
         * NamedAttribute node.
         */
        private Node.JspAttribute getJspAttribute(TagAttributeInfo tai,
                String qName, String uri, String localName, String value,
                Class expectedType, Node n, boolean dynamic)
                throws JasperException {

            Node.JspAttribute result = null;

            // XXX Is it an error to see "%=foo%" in non-Xml page?
            // (We won't see "<%=foo%> in xml page because '<' is not a
            // valid attribute value in xml).

            if (value != null) {
                if (n.getRoot().isXmlSyntax() && value.startsWith("%=")) {
                    result = new Node.JspAttribute(tai, qName, uri, localName,
                            value.substring(2, value.length() - 1), true, null,
                            dynamic);
                } else if (!n.getRoot().isXmlSyntax()
                        && value.startsWith("<%=")) {
                    result = new Node.JspAttribute(tai, qName, uri, localName,
                            value.substring(3, value.length() - 2), true, null,
                            dynamic);
                } else {
                    // The attribute can contain expressions but is not a
                    // scriptlet expression; thus, we want to run it through
                    // the expression interpreter

                    // validate expression syntax if string contains
                    // expression(s)
                    ELNode.Nodes el = ELParser.parse(value);
                    
                    boolean deferred = false;
                    Iterator<ELNode> nodes = el.iterator();
                    while (nodes.hasNext()) {
                        ELNode node = nodes.next();
                        if (node instanceof ELNode.Root) {
                            if (((ELNode.Root) node).getType() == '#') {
                                deferred = true;
                            }
                        }
                    }

                    if (el.containsEL() && !pageInfo.isELIgnored()
                            && ((!pageInfo.isDeferredSyntaxAllowedAsLiteral() && deferred)
                                    || !deferred)) {

                        validateFunctions(el, n);

                        result = new Node.JspAttribute(tai, qName, uri,
                                localName, value, false, el, dynamic);

                        ELContextImpl ctx = new ELContextImpl();
                        ctx.setFunctionMapper(getFunctionMapper(el));

                        try {
                            result.validateEL(this.pageInfo
                                    .getExpressionFactory(), ctx);
                        } catch (ELException e) {
                            this.err.jspError(n.getStart(),
                                    "jsp.error.invalid.expression", value, e
                                            .toString());
                        }

                    } else {
                        value = value.replace(Constants.ESC, '$');
                        result = new Node.JspAttribute(tai, qName, uri,
                                localName, value, false, null, dynamic);
                    }
                }
            } else {
                // Value is null. Check for any NamedAttribute subnodes
                // that might contain the value for this attribute.
                // Otherwise, the attribute wasn't found so we return null.

                Node.NamedAttribute namedAttributeNode = n
                        .getNamedAttributeNode(qName);
                if (namedAttributeNode != null) {
                    result = new Node.JspAttribute(namedAttributeNode, tai,
                            dynamic);
                }
            }

            return result;
        }

        /*
         * Return an empty StringBuffer [not thread-safe]
         */
        private StringBuffer getBuffer() {
            this.buf.setLength(0);
            return this.buf;
        }

        /*
         * Checks to see if the given attribute value represents a runtime or EL
         * expression.
         */
        private boolean isExpression(Node n, String value, boolean checkDeferred) {
            
            boolean runtimeExpression = ((n.getRoot().isXmlSyntax() && value.startsWith("%="))
                    || (!n.getRoot().isXmlSyntax() && value.startsWith("<%=")));
            boolean elExpression = false;

            if (!runtimeExpression && !pageInfo.isELIgnored()) {
                Iterator<ELNode> nodes = ELParser.parse(value).iterator();
                while (nodes.hasNext()) {