1 /*
   2  * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
   3  */
   4 /*
   5  * Licensed to the Apache Software Foundation (ASF) under one or more
   6  * contributor license agreements.  See the NOTICE file distributed with
   7  * this work for additional information regarding copyright ownership.
   8  * The ASF licenses this file to You under the Apache License, Version 2.0
   9  * (the "License"); you may not use this file except in compliance with
  10  * the License.  You may obtain a copy of the License at
  11  *
  12  *      http://www.apache.org/licenses/LICENSE-2.0
  13  *
  14  * Unless required by applicable law or agreed to in writing, software
  15  * distributed under the License is distributed on an "AS IS" BASIS,
  16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  17  * See the License for the specific language governing permissions and
  18  * limitations under the License.
  19  */
  20 
  21 package com.sun.org.apache.xerces.internal.impl.dtd;
  22 
  23 import com.sun.org.apache.xerces.internal.util.XMLResourceIdentifierImpl;
  24 import com.sun.org.apache.xerces.internal.xni.XMLResourceIdentifier;
  25 import com.sun.org.apache.xerces.internal.xni.grammars.XMLGrammarDescription;
  26 import com.sun.org.apache.xerces.internal.xni.parser.XMLInputSource;
  27 import java.util.List;
  28 
  29 /**
  30  * All information specific to DTD grammars.
  31  *
  32  * @xerces.internal
  33  *
  34  * @author Neil Graham, IBM
  35  * @LastModified: Oct 2017
  36  */
  37 public class XMLDTDDescription extends XMLResourceIdentifierImpl
  38         implements com.sun.org.apache.xerces.internal.xni.grammars.XMLDTDDescription {
  39 
  40     // Data
  41 
  42     // pieces of information needed to make this usable as a Grammar key
  43     // if we know the root of this grammar, here's its name:
  44     protected String fRootName = null;
  45 
  46     // if we don't know the root name, this stores all elements that
  47     // could serve; fPossibleRoots and fRootName cannot both be non-null
  48     protected List<String> fPossibleRoots = null;
  49 
  50     // Constructors:
  51     public XMLDTDDescription(XMLResourceIdentifier id, String rootName) {
  52         this.setValues(id.getPublicId(), id.getLiteralSystemId(),
  53                 id.getBaseSystemId(), id.getExpandedSystemId());
  54         this.fRootName = rootName;
  55         this.fPossibleRoots = null;
  56     } // init(XMLResourceIdentifier, String)
  57 
  58     public XMLDTDDescription(String publicId, String literalId,
  59                 String baseId, String expandedId, String rootName) {
  60         this.setValues(publicId, literalId, baseId, expandedId);
  61         this.fRootName = rootName;
  62         this.fPossibleRoots = null;
  63     } // init(String, String, String, String, String)
  64 
  65     public XMLDTDDescription(XMLInputSource source) {
  66         this.setValues(source.getPublicId(), null,
  67                 source.getBaseSystemId(), source.getSystemId());
  68         this.fRootName = null;
  69         this.fPossibleRoots = null;
  70     } // init(XMLInputSource)
  71 
  72     // XMLGrammarDescription methods
  73 
  74     public String getGrammarType () {
  75         return XMLGrammarDescription.XML_DTD;
  76     } // getGrammarType():  String
  77 
  78     /**
  79      * @return the root name of this DTD or null if root name is unknown
  80      */
  81     public String getRootName() {
  82         return fRootName;
  83     } // getRootName():  String
  84 
  85     /** Set the root name **/
  86     public void setRootName(String rootName) {
  87         fRootName = rootName;
  88         fPossibleRoots = null;
  89     }
  90 
  91     /** Set possible roots **/
  92     public void setPossibleRoots(List<String> possibleRoots) {
  93         fPossibleRoots = possibleRoots;
  94     }
  95 
  96     /**
  97      * Compares this grammar with the given grammar. Currently, we compare
  98      * as follows:
  99      * - if grammar type not equal return false immediately
 100      * - try and find a common root name:
 101      *    - if both have roots, use them
 102      *    - else if one has a root, examine other's possible root's for a match;
 103      *    - else try all combinations
 104      *  - test fExpandedSystemId and fPublicId as above
 105      *
 106      * @param desc The description of the grammar to be compared with
 107      * @return     True if they are equal, else false
 108      */
 109     public boolean equals(Object desc) {
 110         if (!(desc instanceof XMLGrammarDescription)) return false;
 111         if (!getGrammarType().equals(((XMLGrammarDescription)desc).getGrammarType())) {
 112             return false;
 113         }
 114         // assume it's a DTDDescription
 115         XMLDTDDescription dtdDesc = (XMLDTDDescription)desc;
 116         if (fRootName != null) {
 117             if ((dtdDesc.fRootName) != null && !dtdDesc.fRootName.equals(fRootName)) {
 118                 return false;
 119             }
 120             else if (dtdDesc.fPossibleRoots != null && !dtdDesc.fPossibleRoots.contains(fRootName)) {
 121                 return false;
 122             }
 123         }
 124         else if (fPossibleRoots != null) {
 125             if (dtdDesc.fRootName != null) {
 126                 if (!fPossibleRoots.contains(dtdDesc.fRootName)) {
 127                     return false;
 128                 }
 129             }
 130             else if (dtdDesc.fPossibleRoots == null) {
 131                 return false;
 132             }
 133             else {
 134                 boolean found = false;
 135                 for (String root : fPossibleRoots) {
 136                     found = dtdDesc.fPossibleRoots.contains(root);
 137                     if (found) break;
 138                 }
 139                 if (!found) return false;
 140             }
 141         }
 142         // if we got this far we've got a root match... try other two fields,
 143         // since so many different DTD's have roots in common:
 144         if (fExpandedSystemId != null) {
 145             if (!fExpandedSystemId.equals(dtdDesc.fExpandedSystemId)) {
 146                 return false;
 147             }
 148         }
 149         else if (dtdDesc.fExpandedSystemId != null) {
 150             return false;
 151         }
 152         if (fPublicId != null) {
 153             if (!fPublicId.equals(dtdDesc.fPublicId)) {
 154                 return false;
 155             }
 156         }
 157         else if (dtdDesc.fPublicId != null) {
 158             return false;
 159         }
 160         return true;
 161     }
 162 
 163     /**
 164      * Returns the hash code of this grammar
 165      * Because our .equals method is so complex, we just return a very
 166      * simple hash that might avoid calls to the equals method a bit...
 167      * @return The hash code
 168      */
 169     public int hashCode() {
 170         if (fExpandedSystemId != null) {
 171             return fExpandedSystemId.hashCode();
 172         }
 173         if (fPublicId != null) {
 174             return fPublicId.hashCode();
 175         }
 176         // give up; hope .equals can handle it:
 177         return 0;
 178     }
 179 } // class XMLDTDDescription