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.ldap.model.message; 021 022 023import java.util.Observable; 024import java.util.Observer; 025 026 027/** 028 * The base abandonable request message class. All such requests have a response 029 * type. 030 * 031 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 032 */ 033public abstract class AbstractAbandonableRequest extends AbstractRequest implements AbandonableRequest 034{ 035 static final long serialVersionUID = -4511116249089399040L; 036 037 /** Flag indicating whether or not this request returns a response. */ 038 private boolean abandoned = false; 039 040 /** A filed used to check if the request has been abandonned */ 041 private RequestObservable observable; 042 043 044 /** 045 * Subclasses must provide these parameters via a super constructor call. 046 * 047 * @param id the sequential message identifier 048 * @param type the request type enum 049 */ 050 protected AbstractAbandonableRequest( final int id, final MessageTypeEnum type ) 051 { 052 super( id, type, true ); 053 } 054 055 056 /** 057 * {@inheritDoc} 058 */ 059 @Override 060 public void abandon() 061 { 062 if ( abandoned ) 063 { 064 return; 065 } 066 067 abandoned = true; 068 069 if ( observable == null ) 070 { 071 observable = new RequestObservable(); 072 } 073 074 observable.setChanged(); 075 observable.notifyObservers(); 076 observable.deleteObservers(); 077 } 078 079 080 /** 081 * {@inheritDoc} 082 */ 083 @Override 084 public boolean isAbandoned() 085 { 086 return abandoned; 087 } 088 089 090 /** 091 * {@inheritDoc} 092 */ 093 @Override 094 public AbandonableRequest addAbandonListener( final AbandonListener listener ) 095 { 096 if ( observable == null ) 097 { 098 observable = new RequestObservable(); 099 } 100 101 observable.addObserver( new Observer() 102 { 103 @Override 104 public void update( Observable o, Object arg ) 105 { 106 listener.requestAbandoned( AbstractAbandonableRequest.this ); 107 } 108 } ); 109 110 return this; 111 } 112 113 // False positive 114 static class RequestObservable extends Observable 115 { 116 @Override 117 public void setChanged() 118 { 119 super.setChanged(); 120 } 121 } 122}