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1   /*
2    * reserved comment block
3    * DO NOT REMOVE OR ALTER!
4    */
5   // CatalogEntry.java - Represents Catalog entries
6   
7   /*
8    * Copyright 2001-2004 The Apache Software Foundation or its licensors,
9    * as applicable.
10   *
11   * Licensed under the Apache License, Version 2.0 (the "License");
12   * you may not use this file except in compliance with the License.
13   * You may obtain a copy of the License at
14   *
15   *      http://www.apache.org/licenses/LICENSE-2.0
16   *
17   * Unless required by applicable law or agreed to in writing, software
18   * distributed under the License is distributed on an "AS IS" BASIS,
19   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
20   * See the License for the specific language governing permissions and
21   * limitations under the License.
22   */
23  
24  package com.sun.org.apache.xml.internal.resolver;
25  
26  import java.util.Hashtable;
27  import java.util.Vector;
28  
29  /**
30   * Represents a Catalog entry.
31   *
32   * <p>Instances of this class represent individual entries
33   * in a Catalog.</p>
34   *
35   * <p>Each catalog entry has a unique name and is associated with
36   * an arbitrary number of arguments (all strings). For example, the
37   * TR9401 catalog entry "PUBLIC" has two arguments, a public identifier
38   * and a system identifier. Each entry has a unique numeric type,
39   * assigned automatically when the entry type is created.</p>
40   *
41   * <p>The number and type of catalog entries is maintained
42   * <em>statically</em>. Catalog classes, or their subclasses, can add
43   * new entry types, but all Catalog objects share the same global pool
44   * of types.</p>
45   *
46   * <p>Initially there are no valid entries.</p>
47   *
48   * @see Catalog
49   *
50   * @author Norman Walsh
51   * <a href="mailto:Norman.Walsh@Sun.COM">Norman.Walsh@Sun.COM</a>
52   *
53   */
54  public class CatalogEntry {
55    /** The nextEntry is the ordinal number of the next entry type. */
56    protected static int nextEntry = 0;
57  
58    /**
59     * The entryTypes vector maps catalog entry names
60     * (e.g., 'BASE' or 'SYSTEM') to their type (1, 2, etc.).
61     * Names are case sensitive.
62     */
63    protected static Hashtable entryTypes = new Hashtable();
64  
65    /** The entryTypes vector maps catalog entry types to the
66        number of arguments they're required to have. */
67    protected static Vector entryArgs = new Vector();
68  
69    /**
70     * Adds a new catalog entry type.
71     *
72     * @param name The name of the catalog entry type. This must be
73     * unique among all types and is case-sensitive. (Adding a duplicate
74     * name effectively replaces the old type with the new type.)
75     * @param numArgs The number of arguments that this entry type
76     * is required to have. There is no provision for variable numbers
77     * of arguments.
78     * @return The type for the new entry.
79     */
80    public static int addEntryType(String name, int numArgs) {
81      entryTypes.put(name, new Integer(nextEntry));
82      entryArgs.add(nextEntry, new Integer(numArgs));
83      nextEntry++;
84  
85      return nextEntry-1;
86    }
87  
88    /**
89     * Lookup an entry type
90     *
91     * @param name The name of the catalog entry type.
92     * @return The type of the catalog entry with the specified name.
93     * @throws InvalidCatalogEntryTypeException if no entry has the
94     * specified name.
95     */
96    public static int getEntryType(String name)
97      throws CatalogException {
98      if (!entryTypes.containsKey(name)) {
99        throw new CatalogException(CatalogException.INVALID_ENTRY_TYPE);
100     }
101 
102     Integer iType = (Integer) entryTypes.get(name);
103 
104     if (iType == null) {
105       throw new CatalogException(CatalogException.INVALID_ENTRY_TYPE);
106     }
107 
108     return iType.intValue();
109   }
110 
111   /**
112    * Find out how many arguments an entry is required to have.
113    *
114    * @param name The name of the catalog entry type.
115    * @return The number of arguments that entry type is required to have.
116    * @throws InvalidCatalogEntryTypeException if no entry has the
117    * specified name.
118    */
119   public static int getEntryArgCount(String name)
120     throws CatalogException {
121     return getEntryArgCount(getEntryType(name));
122   }
123 
124   /**
125    * Find out how many arguments an entry is required to have.
126    *
127    * @param type A valid catalog entry type.
128    * @return The number of arguments that entry type is required to have.
129    * @throws InvalidCatalogEntryTypeException if the type is invalid.
130    */
131   public static int getEntryArgCount(int type)
132     throws CatalogException {
133     try {
134       Integer iArgs = (Integer) entryArgs.get(type);
135       return iArgs.intValue();
136     } catch (ArrayIndexOutOfBoundsException e) {
137       throw new CatalogException(CatalogException.INVALID_ENTRY_TYPE);
138     }
139   }
140 
141   /** The entry type of this entry */
142   protected int entryType = 0;
143 
144   /** The arguments associated with this entry */
145   protected Vector args = null;
146 
147   /**
148    * Null constructor; something for subclasses to call.
149    */
150   public CatalogEntry() {}
151 
152   /**
153    * Construct a catalog entry of the specified type.
154    *
155    * @param name The name of the entry type
156    * @param args A String Vector of arguments
157    * @throws InvalidCatalogEntryTypeException if no such entry type
158    * exists.
159    * @throws InvalidCatalogEntryException if the wrong number of arguments
160    * is passed.
161    */
162   public CatalogEntry(String name, Vector args)
163     throws CatalogException {
164     Integer iType = (Integer) entryTypes.get(name);
165 
166     if (iType == null) {
167       throw new CatalogException(CatalogException.INVALID_ENTRY_TYPE);
168     }
169 
170     int type = iType.intValue();
171 
172     try {
173       Integer iArgs = (Integer) entryArgs.get(type);
174       if (iArgs.intValue() != args.size()) {
175         throw new CatalogException(CatalogException.INVALID_ENTRY);
176       }
177     } catch (ArrayIndexOutOfBoundsException e) {
178       throw new CatalogException(CatalogException.INVALID_ENTRY_TYPE);
179     }
180 
181     entryType = type;
182     this.args = args;
183   }
184 
185   /**
186    * Construct a catalog entry of the specified type.
187    *
188    * @param type The entry type
189    * @param args A String Vector of arguments
190    * @throws InvalidCatalogEntryTypeException if no such entry type
191    * exists.
192    * @throws InvalidCatalogEntryException if the wrong number of arguments
193    * is passed.
194    */
195   public CatalogEntry(int type, Vector args)
196     throws CatalogException {
197     try {
198       Integer iArgs = (Integer) entryArgs.get(type);
199       if (iArgs.intValue() != args.size()) {
200         throw new CatalogException(CatalogException.INVALID_ENTRY);
201       }
202     } catch (ArrayIndexOutOfBoundsException e) {
203       throw new CatalogException(CatalogException.INVALID_ENTRY_TYPE);
204     }
205 
206     entryType = type;
207     this.args = args;
208   }
209 
210   /**
211    * Get the entry type.
212    *
213    * @return The entry type of the CatalogEntry
214    */
215   public int getEntryType() {
216     return entryType;
217   }
218 
219   /**
220    * Get an entry argument.
221    *
222    * @param argNum The argument number (arguments are numbered from 0).
223    * @return The specified argument or null if an invalid argNum is
224    * provided.
225    */
226   public String getEntryArg(int argNum) {
227     try {
228       String arg = (String) args.get(argNum);
229       return arg;
230     } catch (ArrayIndexOutOfBoundsException e) {
231       return null;
232     }
233   }
234 
235   /**
236    * Set an entry argument.
237    *
238    * <p>Catalogs sometimes need to adjust the catlog entry parameters,
239    * for example to make a relative URI absolute with respect to the
240    * current base URI. But in general, this function should only be
241    * called shortly after object creation to do some sort of cleanup.
242    * Catalog entries should not mutate over time.</p>
243    *
244    * @param argNum The argument number (arguments are numbered from 0).
245    * @throws ArrayIndexOutOfBoundsException if an invalid argument
246    * number is provided.
247    */
248   public void setEntryArg(int argNum, String newspec)
249     throws ArrayIndexOutOfBoundsException {
250     args.set(argNum, newspec);
251   }
252 }