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 package org.apache.directory.api.ldap.model.schema.parsers; 21 22 23 import java.io.Reader; 24 25 import org.apache.directory.api.ldap.model.schema.syntaxes.AntlrSchemaLexer; 26 27 import antlr.CharBuffer; 28 import antlr.LexerSharedInputState; 29 30 31 /** 32 * A reusable lexer class extended from antlr generated lexer for an LDAP 33 * schema as defined in RFC 4512. 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 */ 41 public class ReusableAntlrSchemaLexer extends AntlrSchemaLexer 42 { 43 private boolean savedCaseSensitive; 44 45 private boolean savedCaseSensitiveLiterals; 46 47 48 /** 49 * Creates a ReusableAntlrSchemaLexer instance. 50 * 51 * @param in 52 * the input to the lexer 53 */ 54 public ReusableAntlrSchemaLexer( Reader in ) 55 { 56 super( in ); 57 savedCaseSensitive = getCaseSensitive(); 58 savedCaseSensitiveLiterals = getCaseSensitiveLiterals(); 59 } 60 61 62 /** 63 * Resets the state of an antlr lexer and initializes it with new input. 64 * 65 * @param in 66 * the input to the lexer 67 */ 68 public void prepareNextInput( Reader in ) 69 { 70 CharBuffer buf = new CharBuffer( in ); 71 LexerSharedInputState state = new LexerSharedInputState( buf ); 72 this.setInputState( state ); 73 74 this.setCaseSensitive( savedCaseSensitive ); 75 76 // no set method for this protected field. 77 this.caseSensitiveLiterals = savedCaseSensitiveLiterals; 78 } 79 }