validator.java

业界著名的tomcat服务器的最新6.0的源代码。

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.jasper.compiler;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Iterator;

import javax.el.ELException;
import javax.el.ExpressionFactory;
import javax.el.FunctionMapper;
import javax.servlet.jsp.tagext.FunctionInfo;
import javax.servlet.jsp.tagext.JspFragment;
import javax.servlet.jsp.tagext.PageData;
import javax.servlet.jsp.tagext.TagAttributeInfo;
import javax.servlet.jsp.tagext.TagData;
import javax.servlet.jsp.tagext.TagExtraInfo;
import javax.servlet.jsp.tagext.TagInfo;
import javax.servlet.jsp.tagext.TagLibraryInfo;
import javax.servlet.jsp.tagext.ValidationMessage;

import org.apache.el.lang.ELSupport;
import org.apache.jasper.Constants;
import org.apache.jasper.JasperException;
import org.apache.jasper.el.ELContextImpl;
import org.xml.sax.Attributes;

/**
 * Performs validation on the page elements. Attributes are checked for
 * mandatory presence, entry value validity, and consistency. As a side effect,
 * some page global value (such as those from page direcitves) are stored, for
 * later use.
 * 
 * @author Kin-man Chung
 * @author Jan Luehe
 * @author Shawn Bayern
 * @author Mark Roth
 */
class Validator {

    /**
     * A visitor to validate and extract page directive info
     */
    static class DirectiveVisitor extends Node.Visitor {

        private PageInfo pageInfo;

        private ErrorDispatcher err;

        private static final JspUtil.ValidAttribute[] pageDirectiveAttrs = {
            new JspUtil.ValidAttribute("language"),
            new JspUtil.ValidAttribute("extends"),
            new JspUtil.ValidAttribute("import"),
            new JspUtil.ValidAttribute("session"),
            new JspUtil.ValidAttribute("buffer"),
            new JspUtil.ValidAttribute("autoFlush"),
            new JspUtil.ValidAttribute("isThreadSafe"),
            new JspUtil.ValidAttribute("info"),
            new JspUtil.ValidAttribute("errorPage"),
            new JspUtil.ValidAttribute("isErrorPage"),
            new JspUtil.ValidAttribute("contentType"),
            new JspUtil.ValidAttribute("pageEncoding"),
            new JspUtil.ValidAttribute("isELIgnored"),
            new JspUtil.ValidAttribute("deferredSyntaxAllowedAsLiteral"),
            new JspUtil.ValidAttribute("trimDirectiveWhitespaces")
        };

        private boolean pageEncodingSeen = false;

        /*
         * Constructor
         */
        DirectiveVisitor(Compiler compiler) throws JasperException {
            this.pageInfo = compiler.getPageInfo();
            this.err = compiler.getErrorDispatcher();
        }

        public void visit(Node.IncludeDirective n) throws JasperException {
            // Since pageDirectiveSeen flag only applies to the Current page
            // save it here and restore it after the file is included.
            boolean pageEncodingSeenSave = pageEncodingSeen;
            pageEncodingSeen = false;
            visitBody(n);
            pageEncodingSeen = pageEncodingSeenSave;
        }

        public void visit(Node.PageDirective n) throws JasperException {

            JspUtil.checkAttributes("Page directive", n, pageDirectiveAttrs,
                    err);

            // JSP.2.10.1
            Attributes attrs = n.getAttributes();
            for (int i = 0; attrs != null && i < attrs.getLength(); i++) {
                String attr = attrs.getQName(i);
                String value = attrs.getValue(i);

                if ("language".equals(attr)) {
                    if (pageInfo.getLanguage(false) == null) {
                        pageInfo.setLanguage(value, n, err, true);
                    } else if (!pageInfo.getLanguage(false).equals(value)) {
                        err.jspError(n, "jsp.error.page.conflict.language",
                                pageInfo.getLanguage(false), value);
                    }
                } else if ("extends".equals(attr)) {
                    if (pageInfo.getExtends(false) == null) {
                        pageInfo.setExtends(value, n);
                    } else if (!pageInfo.getExtends(false).equals(value)) {
                        err.jspError(n, "jsp.error.page.conflict.extends",
                                pageInfo.getExtends(false), value);
                    }
                } else if ("contentType".equals(attr)) {
                    if (pageInfo.getContentType() == null) {
                        pageInfo.setContentType(value);
                    } else if (!pageInfo.getContentType().equals(value)) {
                        err.jspError(n, "jsp.error.page.conflict.contenttype",
                                pageInfo.getContentType(), value);
                    }
                } else if ("session".equals(attr)) {
                    if (pageInfo.getSession() == null) {
                        pageInfo.setSession(value, n, err);
                    } else if (!pageInfo.getSession().equals(value)) {
                        err.jspError(n, "jsp.error.page.conflict.session",
                                pageInfo.getSession(), value);
                    }
                } else if ("buffer".equals(attr)) {
                    if (pageInfo.getBufferValue() == null) {
                        pageInfo.setBufferValue(value, n, err);
                    } else if (!pageInfo.getBufferValue().equals(value)) {
                        err.jspError(n, "jsp.error.page.conflict.buffer",
                                pageInfo.getBufferValue(), value);
                    }
                } else if ("autoFlush".equals(attr)) {
                    if (pageInfo.getAutoFlush() == null) {
                        pageInfo.setAutoFlush(value, n, err);
                    } else if (!pageInfo.getAutoFlush().equals(value)) {
                        err.jspError(n, "jsp.error.page.conflict.autoflush",
                                pageInfo.getAutoFlush(), value);
                    }
                } else if ("isThreadSafe".equals(attr)) {
                    if (pageInfo.getIsThreadSafe() == null) {
                        pageInfo.setIsThreadSafe(value, n, err);
                    } else if (!pageInfo.getIsThreadSafe().equals(value)) {
                        err.jspError(n, "jsp.error.page.conflict.isthreadsafe",
                                pageInfo.getIsThreadSafe(), value);
                    }
                } else if ("isELIgnored".equals(attr)) {
                    if (pageInfo.getIsELIgnored() == null) {
                        pageInfo.setIsELIgnored(value, n, err, true);
                    } else if (!pageInfo.getIsELIgnored().equals(value)) {
                        err.jspError(n, "jsp.error.page.conflict.iselignored",
                                pageInfo.getIsELIgnored(), value);
                    }
                } else if ("isErrorPage".equals(attr)) {
                    if (pageInfo.getIsErrorPage() == null) {
                        pageInfo.setIsErrorPage(value, n, err);
                    } else if (!pageInfo.getIsErrorPage().equals(value)) {
                        err.jspError(n, "jsp.error.page.conflict.iserrorpage",
                                pageInfo.getIsErrorPage(), value);
                    }
                } else if ("errorPage".equals(attr)) {
                    if (pageInfo.getErrorPage() == null) {
                        pageInfo.setErrorPage(value);
                    } else if (!pageInfo.getErrorPage().equals(value)) {
                        err.jspError(n, "jsp.error.page.conflict.errorpage",
                                pageInfo.getErrorPage(), value);
                    }
                } else if ("info".equals(attr)) {
                    if (pageInfo.getInfo() == null) {
                        pageInfo.setInfo(value);
                    } else if (!pageInfo.getInfo().equals(value)) {
                        err.jspError(n, "jsp.error.page.conflict.info",
                                pageInfo.getInfo(), value);
                    }
                } else if ("pageEncoding".equals(attr)) {
                    if (pageEncodingSeen)
                        err.jspError(n, "jsp.error.page.multi.pageencoding");
                    // 'pageEncoding' can occur at most once per file
                    pageEncodingSeen = true;
                    String actual = comparePageEncodings(value, n);
                    n.getRoot().setPageEncoding(actual);
                } else if ("deferredSyntaxAllowedAsLiteral".equals(attr)) {
                    if (pageInfo.getDeferredSyntaxAllowedAsLiteral() == null) {
                        pageInfo.setDeferredSyntaxAllowedAsLiteral(value, n,
                                err, true);
                    } else if (!pageInfo.getDeferredSyntaxAllowedAsLiteral()
                            .equals(value)) {
                        err
                                .jspError(
                                        n,
                                        "jsp.error.page.conflict.deferredsyntaxallowedasliteral",
                                        pageInfo
                                                .getDeferredSyntaxAllowedAsLiteral(),
                                        value);
                    }
                } else if ("trimDirectiveWhitespaces".equals(attr)) {
                    if (pageInfo.getTrimDirectiveWhitespaces() == null) {
                        pageInfo.setTrimDirectiveWhitespaces(value, n, err,
                                true);
                    } else if (!pageInfo.getTrimDirectiveWhitespaces().equals(
                            value)) {
                        err
                                .jspError(
                                        n,
                                        "jsp.error.page.conflict.trimdirectivewhitespaces",
                                        pageInfo.getTrimDirectiveWhitespaces(),
                                        value);
                    }
                }
            }

            // Check for bad combinations
            if (pageInfo.getBuffer() == 0 && !pageInfo.isAutoFlush())
                err.jspError(n, "jsp.error.page.badCombo");

            // Attributes for imports for this node have been processed by
            // the parsers, just add them to pageInfo.
            pageInfo.addImports(n.getImports());
        }

        public void visit(Node.TagDirective n) throws JasperException {
            // Note: Most of the validation is done in TagFileProcessor
            // when it created a TagInfo object from the
            // tag file in which the directive appeared.

            // This method does additional processing to collect page info

            Attributes attrs = n.getAttributes();
            for (int i = 0; attrs != null && i < attrs.getLength(); i++) {
                String attr = attrs.getQName(i);
                String value = attrs.getValue(i);

                if ("language".equals(attr)) {
                    if (pageInfo.getLanguage(false) == null) {
                        pageInfo.setLanguage(value, n, err, false);
                    } else if (!pageInfo.getLanguage(false).equals(value)) {
                        err.jspError(n, "jsp.error.tag.conflict.language",
                                pageInfo.getLanguage(false), value);
                    }
                } else if ("isELIgnored".equals(attr)) {
                    if (pageInfo.getIsELIgnored() == null) {
                        pageInfo.setIsELIgnored(value, n, err, false);
                    } else if (!pageInfo.getIsELIgnored().equals(value)) {
                        err.jspError(n, "jsp.error.tag.conflict.iselignored",
                                pageInfo.getIsELIgnored(), value);
                    }
                } else if ("pageEncoding".equals(attr)) {
                    if (pageEncodingSeen)
                        err.jspError(n, "jsp.error.tag.multi.pageencoding");
                    pageEncodingSeen = true;
                    compareTagEncodings(value, n);
                    n.getRoot().setPageEncoding(value);
                } else if ("deferredSyntaxAllowedAsLiteral".equals(attr)) {
                    if (pageInfo.getDeferredSyntaxAllowedAsLiteral() == null) {
                        pageInfo.setDeferredSyntaxAllowedAsLiteral(value, n,
                                err, false);
                    } else if (!pageInfo.getDeferredSyntaxAllowedAsLiteral()
                            .equals(value)) {
                        err