1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * https://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 *
19 */
20
21 package org.apache.directory.api.ldap.aci;
22
23
24 import java.io.StringReader;
25 import java.text.ParseException;
26
27 import org.apache.directory.api.i18n.I18n;
28 import org.apache.directory.api.ldap.model.schema.SchemaManager;
29 import org.apache.directory.api.ldap.model.schema.normalizers.NameComponentNormalizer;
30 import org.apache.directory.api.util.StringConstants;
31
32 import antlr.RecognitionException;
33 import antlr.TokenStreamException;
34
35
36 /**
37 * A reusable wrapper around the antlr generated parser for an ACIItem as
38 * defined by X.501. This class enables the reuse of the antlr parser/lexer pair
39 * without having to recreate them every time.
40 *
41 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
42 */
43 public class ACIItemParser
44 {
45 /** the antlr generated parser being wrapped */
46 private ReusableAntlrACIItemParser parser;
47
48 /** the antlr generated lexer being wrapped */
49 private ReusableAntlrACIItemLexer lexer;
50
51 /** The is normalizing flag. */
52 private final boolean isNormalizing;
53
54
55 /**
56 * Creates a ACIItem parser.
57 *
58 * @param schemaManager the schema manager
59 */
60 public ACIItemParser( SchemaManager schemaManager )
61 {
62 this.lexer = new ReusableAntlrACIItemLexer( new StringReader( "" ) );
63 this.parser = new ReusableAntlrACIItemParser( lexer );
64
65 // this method MUST be called while we cannot do
66 // constructor overloading for antlr generated parser
67 this.parser.init( schemaManager );
68
69 this.isNormalizing = false;
70 }
71
72
73 /**
74 * Creates a normalizing ACIItem parser.
75 *
76 * @param normalizer the normalizer
77 * @param schemaManager the schema manager
78 */
79 public ACIItemParser( NameComponentNormalizer normalizer, SchemaManager schemaManager )
80 {
81 this.lexer = new ReusableAntlrACIItemLexer( new StringReader( "" ) );
82 this.parser = new ReusableAntlrACIItemParser( lexer );
83
84 this.parser.setNormalizer( normalizer );
85 this.isNormalizing = true;
86
87 // this method MUST be called while we cannot do
88 // constructor overloading for antlr generated parser
89 this.parser.init( schemaManager );
90 }
91
92
93 /**
94 * Initializes the plumbing by creating a pipe and coupling the parser/lexer
95 * pair with it.
96 *
97 * @param spec the specification to be parsed
98 */
99 private synchronized void reset( String spec )
100 {
101 StringReader in = new StringReader( spec );
102 this.lexer.prepareNextInput( in );
103 this.parser.resetState();
104 }
105
106
107 /**
108 * Parses an ACIItem without exhausting the parser.
109 *
110 * @param spec
111 * the specification to be parsed
112 * @return the specification bean
113 * @throws ParseException
114 * if there are any recognition errors (bad syntax)
115 */
116 public synchronized ACIItem parse( String spec ) throws ParseException
117 {
118 ACIItem aCIItem;
119
120 if ( ( spec == null ) || StringConstants.EMPTY.equals( spec.trim() ) )
121 {
122 return null;
123 }
124
125 // reset and initialize the parser / lexer pair
126 reset( spec );
127
128 try
129 {
130 aCIItem = this.parser.wrapperEntryPoint();
131 }
132 catch ( TokenStreamException e )
133 {
134 throw new ParseException( I18n
135 .err( I18n.ERR_07004_PARSER_FAILURE_ACI_ITEM, spec, e.getLocalizedMessage() ), 0 );
136 }
137 catch ( RecognitionException e )
138 {
139 throw new ParseException(
140 I18n
141 .err( I18n.ERR_07004_PARSER_FAILURE_ACI_ITEM, spec, e.getLocalizedMessage(), e.getLine(),
142 e.getColumn() ), e.getColumn() );
143 }
144
145 return aCIItem;
146 }
147
148
149 /**
150 * Tests to see if this parser is normalizing.
151 *
152 * @return true if it normalizes false otherwise
153 */
154 public boolean isNormizing()
155 {
156 return this.isNormalizing;
157 }
158 }