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.model.subtree; 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 public class ReusableAntlrSubtreeSpecificationLexer extends AntlrSubtreeSpecificationLexer 43 { 44 private boolean savedCaseSensitive; 45 46 private boolean savedCaseSensitiveLiterals; 47 48 49 /** 50 * Creates a ReusableAntlrSubtreeSpecificationLexer instance. 51 * 52 * @param in 53 * the input to the lexer 54 */ 55 public ReusableAntlrSubtreeSpecificationLexer( Reader in ) 56 { 57 super( in ); 58 savedCaseSensitive = getCaseSensitive(); 59 savedCaseSensitiveLiterals = getCaseSensitiveLiterals(); 60 } 61 62 63 /** 64 * Resets the state of an antlr lexer and initializes it with new input. 65 * 66 * @param in 67 * the input to the lexer 68 */ 69 public void prepareNextInput( Reader in ) 70 { 71 CharBuffer buf = new CharBuffer( in ); 72 LexerSharedInputState state = new LexerSharedInputState( buf ); 73 this.setInputState( state ); 74 75 this.setCaseSensitive( savedCaseSensitive ); 76 77 // no set method for this protected field. 78 this.caseSensitiveLiterals = savedCaseSensitiveLiterals; 79 } 80 }