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