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 * http://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.Reader; 25 26 import antlr.CharBuffer; 27 import antlr.LexerSharedInputState; 28 29 30 /** 31 * A reusable lexer class extended from antlr generated lexer for an LDAP 32 * subtree specification as defined by <a 33 * href="http://www.faqs.org/rfcs/rfc3672.html"> RFC 3672</a>. This class 34 * enables the reuse of the antlr lexer without having to recreate the it every 35 * time as stated in <a 36 * href="http://www.antlr.org:8080/pipermail/antlr-interest/2003-April/003631.html"> 37 * a Antlr Interest Group mail</a> . 38 * 39 * @see <a href="http://www.faqs.org/rfcs/rfc3672.html">RFC 3672</a> 40 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 41 */ 42 class ReusableAntlrACIItemCheckerLexer extends AntlrACIItemCheckerLexer 43 { 44 45 /** The saved case sensitive flag. */ 46 private boolean savedCaseSensitive; 47 48 /** The saved case sensitive literals flag. */ 49 private boolean savedCaseSensitiveLiterals; 50 51 52 /** 53 * Creates a ReusableAntlrACIItemCheckerLexer instance. 54 * 55 * @param in 56 * the input to the lexer 57 */ 58 public ReusableAntlrACIItemCheckerLexer( Reader in ) 59 { 60 super( in ); 61 savedCaseSensitive = getCaseSensitive(); 62 savedCaseSensitiveLiterals = getCaseSensitiveLiterals(); 63 } 64 65 66 /** 67 * Resets the state of an antlr lexer and initializes it with new input. 68 * 69 * @param in 70 * the input to the lexer 71 */ 72 public void prepareNextInput( Reader in ) 73 { 74 CharBuffer buf = new CharBuffer( in ); 75 LexerSharedInputState state = new LexerSharedInputState( buf ); 76 this.setInputState( state ); 77 78 this.setCaseSensitive( savedCaseSensitive ); 79 80 // no set method for this protected field. 81 this.caseSensitiveLiterals = savedCaseSensitiveLiterals; 82 } 83 }