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 */ 020 021 package org.apache.directory.shared.ldap.aci; 022 023 024 import java.io.StringReader; 025 import java.text.ParseException; 026 027 import org.apache.directory.shared.i18n.I18n; 028 029 import antlr.RecognitionException; 030 import antlr.TokenStreamException; 031 032 033 /** 034 * A reusable wrapper around the antlr generated parser for an ACIItem as 035 * defined by X.501. This class enables the reuse of the antlr parser/lexer pair 036 * without having to recreate them every time. 037 * 038 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 039 * @version $Rev: 437007 $ 040 */ 041 public class ACIItemChecker 042 { 043 /** the antlr generated parser being wrapped */ 044 private ReusableAntlrACIItemParser checker; 045 046 /** the antlr generated lexer being wrapped */ 047 private ReusableAntlrACIItemLexer lexer; 048 049 private final boolean isNormalizing; 050 051 052 /** 053 * Creates a ACIItem parser. 054 */ 055 public ACIItemChecker() 056 { 057 this.lexer = new ReusableAntlrACIItemLexer( new StringReader( "" ) ); 058 this.checker = new ReusableAntlrACIItemParser( lexer ); 059 this.isNormalizing = false; 060 } 061 062 063 /** 064 * Initializes the plumbing by creating a pipe and coupling the parser/lexer 065 * pair with it. param spec the specification to be parsed 066 */ 067 private synchronized void reset( String spec ) 068 { 069 StringReader in = new StringReader( spec ); 070 this.lexer.prepareNextInput( in ); 071 this.checker.resetState(); 072 } 073 074 075 /** 076 * Parses an ACIItem without exhausting the parser. 077 * 078 * @param spec 079 * the specification to be parsed 080 * @return the specification bean 081 * @throws ParseException 082 * if there are any recognition errors (bad syntax) 083 */ 084 public synchronized void parse( String spec ) throws ParseException 085 { 086 if ( spec == null || spec.trim().equals( "" ) ) 087 { 088 return; 089 } 090 091 reset( spec ); // reset and initialize the parser / lexer pair 092 093 try 094 { 095 this.checker.wrapperEntryPoint(); 096 } 097 catch ( TokenStreamException e ) 098 { 099 throw new ParseException( I18n.err( I18n.ERR_00004, spec, e.getLocalizedMessage() ), 0 ); 100 } 101 catch ( RecognitionException e ) 102 { 103 throw new ParseException( I18n.err( I18n.ERR_00004, spec, e.getLocalizedMessage() ), e.getColumn() ); 104 } 105 106 return; 107 } 108 109 110 /** 111 * Tests to see if this parser is normalizing. 112 * 113 * @return true if it normalizes false otherwise 114 */ 115 public boolean isNormizing() 116 { 117 return this.isNormalizing; 118 } 119 }