validator.java

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/*
 * Copyright 1999,2004-2005 The Apache Software Foundation.
 * 
 * Licensed 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.servlet.jsp.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.jasper.Constants;
import org.apache.jasper.JasperException;
import org.apache.jasper.JspCompilationContext;
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")
	};

	private boolean pageEncodingSeen = false;

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

	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;
		    comparePageEncodings(value, n);
		}
	    }

	    // 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;
		    n.getRoot().setPageEncoding(value);
		}
	    }

	    // 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.AttributeDirective n) throws JasperException {
	    // Do nothing, since this attribute directive has already been
	    // validated by TagFileProcessor when it created a TagInfo object
	    // from the tag file in which the directive appeared
	}

	public void visit(Node.VariableDirective n) throws JasperException {
	    // Do nothing, since this variable directive has already been
	    // validated by TagFileProcessor when it created a TagInfo object
	    // from the tag file in which the directive appeared
	}

        /*
         * Compares page encodings specified in various places, and throws
         * exception in case of page encoding mismatch.
         *
         * @param pageDirEnc The value of the pageEncoding attribute of the
         * page directive
         * @param pageDir The page directive node
         *
         * @throws JasperException in case of page encoding mismatch
         */
        private void comparePageEncodings(String pageDirEnc,
                                          Node.PageDirective pageDir)
                throws JasperException {

            Node.Root root = pageDir.getRoot();
            String configEnc = root.getJspConfigPageEncoding();

            /*
             * Compare the 'pageEncoding' attribute of the page directive with
             * the encoding specified in the JSP config element whose URL
             * pattern matches this page.
             * Treat "UTF-16", "UTF-16BE", and "UTF-16LE" as identical.
             */
            if (configEnc != null && !pageDirEnc.equals(configEnc) 
                    && (!pageDirEnc.startsWith("UTF-16")
                        || !configEnc.startsWith("UTF-16"))) {
                err.jspError(pageDir,
                             "jsp.error.config_pagedir_encoding_mismatch",
                             configEnc, pageDirEnc);
            }

            /*
             * Compare the 'pageEncoding' attribute of the page directive with
             * the encoding specified in the XML prolog (only for XML syntax,
             * and only if JSP document contains XML prolog with encoding
             * declaration).
             * Treat "UTF-16", "UTF-16BE", and "UTF-16LE" as identical.
             */
	    if (root.isXmlSyntax() && root.isEncodingSpecifiedInProlog()) {
		String pageEnc = root.getPageEncoding();
                if (!pageDirEnc.equals(pageEnc) 
                        && (!pageDirEnc.startsWith("UTF-16")
                            || !pageEnc.startsWith("UTF-16"))) {
                    err.jspError(pageDir,
                                 "jsp.error.prolog_pagedir_encoding_mismatch",
                                 pageEnc, pageDirEnc);
                }
            }
        }
    }

    /**
     * A visitor for validating nodes other than page directives
     */
    static class ValidateVisitor extends Node.Visitor {

	private PageInfo pageInfo;
	private ErrorDispatcher err;
	private TagInfo tagInfo;
        private ClassLoader loader;

	private static final JspUtil.ValidAttribute[] jspRootAttrs = {
            new JspUtil.ValidAttribute("xsi:schemaLocation"),
	    new JspUtil.ValidAttribute("version", true) };

	private static final JspUtil.ValidAttribute[] includeDirectiveAttrs = {
	    new JspUtil.ValidAttribute("file", true) };

	private static final JspUtil.ValidAttribute[] taglibDirectiveAttrs = {
	    new JspUtil.ValidAttribute("uri"),
	    new JspUtil.ValidAttribute("tagdir"),
	    new JspUtil.ValidAttribute("prefix", true) };

	private static final JspUtil.ValidAttribute[] includeActionAttrs = {
	    new JspUtil.ValidAttribute("page", true, true),
	    new JspUtil.ValidAttribute("flush") };

	private static final JspUtil.ValidAttribute[] paramActionAttrs = {
	    new JspUtil.ValidAttribute("name", true),
	    new JspUtil.ValidAttribute("value", true, true) };

	private static final JspUtil.ValidAttribute[] forwardActionAttrs = {
	    new JspUtil.ValidAttribute("page", true, true) };

	private static final JspUtil.ValidAttribute[] getPropertyAttrs = {
	    new JspUtil.ValidAttribute("name", true),
	    new JspUtil.ValidAttribute("property", true) };

	private static final JspUtil.ValidAttribute[] setPropertyAttrs = {
	    new JspUtil.ValidAttribute("name", true),
	    new JspUtil.ValidAttribute("property", true),
	    new JspUtil.ValidAttribute("value", false, true),
	    new JspUtil.ValidAttribute("param") };

	private static final JspUtil.ValidAttribute[] useBeanAttrs = {
	    new JspUtil.ValidAttribute("id", true),
	    new JspUtil.ValidAttribute("scope"),
	    new JspUtil.ValidAttribute("class"),
	    new JspUtil.ValidAttribute("type"),
	    new JspUtil.ValidAttribute("beanName", false, true) };

	private static final JspUtil.ValidAttribute[] plugInAttrs = {
	    new JspUtil.ValidAttribute("type",true),
	    new JspUtil.ValidAttribute("code", true),
	    new JspUtil.ValidAttribute("codebase"),
	    new JspUtil.ValidAttribute("align"),
	    new JspUtil.ValidAttribute("archive"),
	    new JspUtil.ValidAttribute("height", false, true),
	    new JspUtil.ValidAttribute("hspace"),
	    new JspUtil.ValidAttribute("jreversion"),
	    new JspUtil.ValidAttribute("name"),
	    new JspUtil.ValidAttribute("vspace"),
	    new JspUtil.ValidAttribute("width", false, true),
	    new JspUtil.ValidAttribute("nspluginurl"),
	    new JspUtil.ValidAttribute("iepluginurl") };
            
        private static final JspUtil.ValidAttribute[] attributeAttrs = {
            new JspUtil.ValidAttribute("name", true),
            new JspUtil.ValidAttribute("trim") };
            
        private static final JspUtil.ValidAttribute[] invokeAttrs = {
            new JspUtil.ValidAttribute("fragment", true),
	    new JspUtil.ValidAttribute("var"),
	    new JspUtil.ValidAttribute("varReader"),
	    new JspUtil.ValidAttribute("scope") };

        private static final JspUtil.ValidAttribute[] doBodyAttrs = {
            new JspUtil.ValidAttribute("var"),
	    new JspUtil.ValidAttribute("varReader"),
	    new JspUtil.ValidAttribute("scope") };

	private static final JspUtil.ValidAttribute[] jspOutputAttrs = {
	    new JspUtil.ValidAttribute("omit-xml-declaration"),
	    new JspUtil.ValidAttribute("doctype-root-element"),
	    new JspUtil.ValidAttribute("doctype-public"),