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 * https://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 */ 020package org.apache.directory.api.dsmlv2; 021 022 023/** 024 * Define a transition between two states of a grammar. It stores the next 025 * state, and the action to execute while transiting. 026 * 027 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 028 */ 029public class GrammarTransition 030{ 031 /** The next state in the grammar */ 032 private Enum<Dsmlv2StatesEnum> nextState; 033 034 /** The action associated to the transition */ 035 private GrammarAction action; 036 037 /** The current state */ 038 private Enum<Dsmlv2StatesEnum> currentState; 039 040 041 /** 042 * Creates a new GrammarTransition object. 043 * 044 * @param currentState The current transition 045 * @param nextState The target state 046 * @param action The action to execute. It could be null. 047 */ 048 public GrammarTransition( Enum<Dsmlv2StatesEnum> currentState, Enum<Dsmlv2StatesEnum> nextState, 049 GrammarAction action ) 050 { 051 this.currentState = currentState; 052 this.nextState = nextState; 053 this.action = action; 054 } 055 056 057 /** 058 * Gets the target state 059 * 060 * @return the target state. 061 */ 062 public Enum<Dsmlv2StatesEnum> getNextState() 063 { 064 return nextState; 065 } 066 067 068 /** 069 * Tells if the transition has an associated action. 070 * 071 * @return <code>true</code> if an action has been associated to the transition 072 */ 073 public boolean hasAction() 074 { 075 return action != null; 076 } 077 078 079 /** 080 * Gets the action associated with the transition 081 * 082 * @return the action associated with the transition 083 */ 084 public GrammarAction getAction() 085 { 086 return action; 087 } 088 089 090 /** 091 * Returns a representation of the transition as a string 092 * 093 * @param grammar the grammar which state we want a String from 094 * @param statesEnum the states enum that contains the states' names 095 * @return a representation of the transition as a string. 096 */ 097 public String toString( int grammar, Enum<Dsmlv2StatesEnum> statesEnum ) 098 { 099 100 StringBuilder sb = new StringBuilder(); 101 102 sb.append( "Transition from <" ).append( currentState ).append( "> to <" ).append( 103 nextState ).append( ">, action : " ).append( 104 ( action == null ) ? "no action" : action.toString() ).append( ">" ); 105 106 return sb.toString(); 107 } 108}