tagfileprocessor.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.io.FileNotFoundException;
import java.io.IOException;
import java.net.URLClassLoader;
import java.util.Iterator;
import java.util.List;
import java.util.Vector;
import java.util.HashMap;

import javax.el.MethodExpression;
import javax.el.ValueExpression;
import javax.servlet.jsp.tagext.TagAttributeInfo;
import javax.servlet.jsp.tagext.TagExtraInfo;
import javax.servlet.jsp.tagext.TagFileInfo;
import javax.servlet.jsp.tagext.TagInfo;
import javax.servlet.jsp.tagext.TagLibraryInfo;
import javax.servlet.jsp.tagext.TagVariableInfo;
import javax.servlet.jsp.tagext.VariableInfo;

import org.apache.jasper.JasperException;
import org.apache.jasper.JspCompilationContext;
import org.apache.jasper.servlet.JspServletWrapper;
import org.apache.jasper.runtime.JspSourceDependent;

/**
 * 1. Processes and extracts the directive info in a tag file. 2. Compiles and
 * loads tag files used in a JSP file.
 * 
 * @author Kin-man Chung
 */

class TagFileProcessor {

    private Vector tempVector;

    /**
     * A visitor the tag file
     */
    private static class TagFileDirectiveVisitor extends Node.Visitor {

        private static final JspUtil.ValidAttribute[] tagDirectiveAttrs = {
                new JspUtil.ValidAttribute("display-name"),
                new JspUtil.ValidAttribute("body-content"),
                new JspUtil.ValidAttribute("dynamic-attributes"),
                new JspUtil.ValidAttribute("small-icon"),
                new JspUtil.ValidAttribute("large-icon"),
                new JspUtil.ValidAttribute("description"),
                new JspUtil.ValidAttribute("example"),
                new JspUtil.ValidAttribute("pageEncoding"),
                new JspUtil.ValidAttribute("language"),
                new JspUtil.ValidAttribute("import"),
                new JspUtil.ValidAttribute("deferredSyntaxAllowedAsLiteral"), // JSP 2.1
                new JspUtil.ValidAttribute("trimDirectiveWhitespaces"), // JSP 2.1
                new JspUtil.ValidAttribute("isELIgnored") };

        private static final JspUtil.ValidAttribute[] attributeDirectiveAttrs = {
                new JspUtil.ValidAttribute("name", true),
                new JspUtil.ValidAttribute("required"),
                new JspUtil.ValidAttribute("fragment"),
                new JspUtil.ValidAttribute("rtexprvalue"),
                new JspUtil.ValidAttribute("type"),
                new JspUtil.ValidAttribute("deferredValue"),            // JSP 2.1
                new JspUtil.ValidAttribute("deferredValueType"),        // JSP 2.1
                new JspUtil.ValidAttribute("deferredMethod"),           // JSP 2
                new JspUtil.ValidAttribute("deferredMethodSignature"),  // JSP 21
                new JspUtil.ValidAttribute("description") };

        private static final JspUtil.ValidAttribute[] variableDirectiveAttrs = {
                new JspUtil.ValidAttribute("name-given"),
                new JspUtil.ValidAttribute("name-from-attribute"),
                new JspUtil.ValidAttribute("alias"),
                new JspUtil.ValidAttribute("variable-class"),
                new JspUtil.ValidAttribute("scope"),
                new JspUtil.ValidAttribute("declare"),
                new JspUtil.ValidAttribute("description") };

        private ErrorDispatcher err;

        private TagLibraryInfo tagLibInfo;

        private String name = null;

        private String path = null;

        private TagExtraInfo tei = null;

        private String bodycontent = null;

        private String description = null;

        private String displayName = null;

        private String smallIcon = null;

        private String largeIcon = null;

        private String dynamicAttrsMapName;

        private String example = null;

        private Vector attributeVector;

        private Vector variableVector;

        private static final String ATTR_NAME = "the name attribute of the attribute directive";

        private static final String VAR_NAME_GIVEN = "the name-given attribute of the variable directive";

        private static final String VAR_NAME_FROM = "the name-from-attribute attribute of the variable directive";

        private static final String VAR_ALIAS = "the alias attribute of the variable directive";

        private static final String TAG_DYNAMIC = "the dynamic-attributes attribute of the tag directive";

        private HashMap nameTable = new HashMap();

        private HashMap nameFromTable = new HashMap();

        public TagFileDirectiveVisitor(Compiler compiler,
                TagLibraryInfo tagLibInfo, String name, String path) {
            err = compiler.getErrorDispatcher();
            this.tagLibInfo = tagLibInfo;
            this.name = name;
            this.path = path;
            attributeVector = new Vector();
            variableVector = new Vector();
        }

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

            JspUtil.checkAttributes("Tag directive", n, tagDirectiveAttrs, err);

            bodycontent = checkConflict(n, bodycontent, "body-content");
            if (bodycontent != null
                    && !bodycontent
                            .equalsIgnoreCase(TagInfo.BODY_CONTENT_EMPTY)
                    && !bodycontent
                            .equalsIgnoreCase(TagInfo.BODY_CONTENT_TAG_DEPENDENT)
                    && !bodycontent
                            .equalsIgnoreCase(TagInfo.BODY_CONTENT_SCRIPTLESS)) {
                err.jspError(n, "jsp.error.tagdirective.badbodycontent",
                        bodycontent);
            }
            dynamicAttrsMapName = checkConflict(n, dynamicAttrsMapName,
                    "dynamic-attributes");
            if (dynamicAttrsMapName != null) {
                checkUniqueName(dynamicAttrsMapName, TAG_DYNAMIC, n);
            }
            smallIcon = checkConflict(n, smallIcon, "small-icon");
            largeIcon = checkConflict(n, largeIcon, "large-icon");
            description = checkConflict(n, description, "description");
            displayName = checkConflict(n, displayName, "display-name");
            example = checkConflict(n, example, "example");
        }

        private String checkConflict(Node n, String oldAttrValue, String attr)
                throws JasperException {

            String result = oldAttrValue;
            String attrValue = n.getAttributeValue(attr);
            if (attrValue != null) {
                if (oldAttrValue != null && !oldAttrValue.equals(attrValue)) {
                    err.jspError(n, "jsp.error.tag.conflict.attr", attr,
                            oldAttrValue, attrValue);
                }
                result = attrValue;
            }
            return result;
        }

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

            JspUtil.checkAttributes("Attribute directive", n,
                    attributeDirectiveAttrs, err);

            // JSP 2.1 Table JSP.8-3
            // handle deferredValue and deferredValueType
            boolean deferredValue = false;
            boolean deferredValueSpecified = false;
            String deferredValueString = n.getAttributeValue("deferredValue");
            if (deferredValueString != null) {
                deferredValueSpecified = true;
                deferredValue = JspUtil.booleanValue(deferredValueString);
            }
            String deferredValueType = n.getAttributeValue("deferredValueType");
            if (deferredValueType != null) {
                if (deferredValueSpecified && !deferredValue) {
                    err.jspError(n, "jsp.error.deferredvaluetypewithoutdeferredvalue");
                } else {
                    deferredValue = true;
                }
            } else if (deferredValue) {
                deferredValueType = "java.lang.Object";
            } else {
                deferredValueType = "java.lang.String";
            }

            // JSP 2.1 Table JSP.8-3
            // handle deferredMethod and deferredMethodSignature
            boolean deferredMethod = false;
            boolean deferredMethodSpecified = false;
            String deferredMethodString = n.getAttributeValue("deferredMethod");
            if (deferredMethodString != null) {
                deferredMethodSpecified = true;
                deferredMethod = JspUtil.booleanValue(deferredMethodString);
            }
            String deferredMethodSignature = n
                    .getAttributeValue("deferredMethodSignature");
            if (deferredMethodSignature != null) {
                if (deferredMethodSpecified && !deferredMethod) {
                    err.jspError(n, "jsp.error.deferredmethodsignaturewithoutdeferredmethod");
                } else {
                    deferredMethod = true;
                }
            } else if (deferredMethod) {
                deferredMethodSignature = "void methodname()";
            }

            if (deferredMethod && deferredValue) {
                err.jspError(n, "jsp.error.deferredmethodandvalue");
            }
            
            String attrName = n.getAttributeValue("name");
            boolean required = JspUtil.booleanValue(n
                    .getAttributeValue("required"));
            boolean rtexprvalue = true;
            String rtexprvalueString = n.getAttributeValue("rtexprvalue");
            if (rtexprvalueString != null) {
                rtexprvalue = JspUtil.booleanValue(rtexprvalueString);
            }
            boolean fragment = JspUtil.booleanValue(n
                    .getAttributeValue("fragment"));
            String type = n.getAttributeValue("type");
            if (fragment) {
                // type is fixed to "JspFragment" and a translation error
                // must occur if specified.
                if (type != null) {
                    err.jspError(n, "jsp.error.fragmentwithtype");
                }
                // rtexprvalue is fixed to "true" and a translation error
                // must occur if specified.
                rtexprvalue = true;
                if (rtexprvalueString != null) {
                    err.jspError(n, "jsp.error.frgmentwithrtexprvalue");
                }
            } else {
                if (type == null)
                    type = "java.lang.String";
                
                if (deferredValue) {
                    type = ValueExpression.class.getName();
                } else if (deferredMethod) {
                    type = MethodExpression.class.getName();
                }
            }

            if (("2.0".equals(tagLibInfo.getRequiredVersion()) || ("1.2".equals(tagLibInfo.getRequiredVersion())))
                    && (deferredMethodSpecified || deferredMethod
                            || deferredValueSpecified || deferredValue)) {
                err.jspError("jsp.error.invalid.version", path);
            }
            
            TagAttributeInfo tagAttributeInfo = new TagAttributeInfo(attrName,
                    required, type, rtexprvalue, fragment, null, deferredValue,
                    deferredMethod, deferredValueType, deferredMethodSignature);
            attributeVector.addElement(tagAttributeInfo);
            checkUniqueName(attrName, ATTR_NAME, n, tagAttributeInfo);
        }

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

            JspUtil.checkAttributes("Variable directive", n,
                    variableDirectiveAttrs, err);

            String nameGiven = n.getAttributeValue("name-given");
            String nameFromAttribute = n
                    .getAttributeValue("name-from-attribute");
            if (nameGiven == null && nameFromAttribute == null) {
                err.jspError("jsp.error.variable.either.name");
            }

            if (nameGiven != null && nameFromAttribute != null) {
                err.jspError("jsp.error.variable.both.name");
            }

            String alias = n.getAttributeValue("alias");
            if (nameFromAttribute != null && alias == null
                    || nameFromAttribute == null && alias != null) {
                err.jspError("jsp.error.variable.alias");
            }

            String className = n.getAttributeValue("variable-class");
            if (className == null)
                className = "java.lang.String";

            String declareStr = n.getAttributeValue("declare");
            boolean declare = true;
            if (declareStr != null)
                declare = JspUtil.booleanValue(declareStr);

            int scope = VariableInfo.NESTED;
            String scopeStr = n.getAttributeValue("scope");
            if (scopeStr != null) {
                if ("NESTED".equals(scopeStr)) {
                    // Already the default
                } else if ("AT_BEGIN".equals(scopeStr)) {
                    scope = VariableInfo.AT_BEGIN;
                } else if ("AT_END".equals(scopeStr)) {
                    scope = VariableInfo.AT_END;
                }
            }

            if (nameFromAttribute != null) {
                /*
                 * An alias has been specified. We use 'nameGiven' to hold the
                 * value of the alias, and 'nameFromAttribute' to hold the name
                 * of the attribute whose value (at invocation-time) denotes the