001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 * 019 */ 020 021package org.apache.directory.api.ldap.aci; 022 023 024import java.io.StringReader; 025import java.text.ParseException; 026 027import org.apache.directory.api.i18n.I18n; 028import org.apache.directory.api.ldap.model.schema.SchemaManager; 029import org.apache.directory.api.ldap.model.schema.normalizers.NameComponentNormalizer; 030import org.apache.directory.api.util.StringConstants; 031 032import antlr.RecognitionException; 033import antlr.TokenStreamException; 034 035 036/** 037 * A reusable wrapper around the antlr generated parser for an ACIItem as 038 * defined by X.501. This class enables the reuse of the antlr parser/lexer pair 039 * without having to recreate them every time. 040 * 041 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 042 */ 043public class ACIItemParser 044{ 045 /** the antlr generated parser being wrapped */ 046 private ReusableAntlrACIItemParser parser; 047 048 /** the antlr generated lexer being wrapped */ 049 private ReusableAntlrACIItemLexer lexer; 050 051 /** The is normalizing flag. */ 052 private final boolean isNormalizing; 053 054 055 /** 056 * Creates a ACIItem parser. 057 * 058 * @param schemaManager the schema manager 059 */ 060 public ACIItemParser( SchemaManager schemaManager ) 061 { 062 this.lexer = new ReusableAntlrACIItemLexer( new StringReader( "" ) ); 063 this.parser = new ReusableAntlrACIItemParser( lexer ); 064 065 // this method MUST be called while we cannot do 066 // constructor overloading for antlr generated parser 067 this.parser.init( schemaManager ); 068 069 this.isNormalizing = false; 070 } 071 072 073 /** 074 * Creates a normalizing ACIItem parser. 075 * 076 * @param normalizer the normalizer 077 * @param schemaManager the schema manager 078 */ 079 public ACIItemParser( NameComponentNormalizer normalizer, SchemaManager schemaManager ) 080 { 081 this.lexer = new ReusableAntlrACIItemLexer( new StringReader( "" ) ); 082 this.parser = new ReusableAntlrACIItemParser( lexer ); 083 084 this.parser.setNormalizer( normalizer ); 085 this.isNormalizing = true; 086 087 // this method MUST be called while we cannot do 088 // constructor overloading for antlr generated parser 089 this.parser.init( schemaManager ); 090 } 091 092 093 /** 094 * Initializes the plumbing by creating a pipe and coupling the parser/lexer 095 * pair with it. param spec the specification to be parsed 096 */ 097 private synchronized void reset( String spec ) 098 { 099 StringReader in = new StringReader( spec ); 100 this.lexer.prepareNextInput( in ); 101 this.parser.resetState(); 102 } 103 104 105 /** 106 * Parses an ACIItem without exhausting the parser. 107 * 108 * @param spec 109 * the specification to be parsed 110 * @return the specification bean 111 * @throws ParseException 112 * if there are any recognition errors (bad syntax) 113 */ 114 public synchronized ACIItem parse( String spec ) throws ParseException 115 { 116 ACIItem aCIItem; 117 118 if ( spec == null || StringConstants.EMPTY .equals( spec.trim() ) ) 119 { 120 return null; 121 } 122 123 // reset and initialize the parser / lexer pair 124 reset( spec ); 125 126 try 127 { 128 aCIItem = this.parser.wrapperEntryPoint(); 129 } 130 catch ( TokenStreamException e ) 131 { 132 throw new ParseException( I18n 133 .err( I18n.ERR_04004_PARSER_FAILURE_ACI_ITEM, spec, e.getLocalizedMessage() ), 0 ); 134 } 135 catch ( RecognitionException e ) 136 { 137 throw new ParseException( 138 I18n 139 .err( I18n.ERR_04004_PARSER_FAILURE_ACI_ITEM, spec, e.getLocalizedMessage(), e.getLine(), 140 e.getColumn() ), e.getColumn() ); 141 } 142 143 return aCIItem; 144 } 145 146 147 /** 148 * Tests to see if this parser is normalizing. 149 * 150 * @return true if it normalizes false otherwise 151 */ 152 public boolean isNormizing() 153 { 154 return this.isNormalizing; 155 } 156}