001/** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.camel.spi; 018 019import org.apache.camel.Exchange; 020 021/** 022 * Access to a repository of Message IDs to implement the 023 * <a href="http://camel.apache.org/idempotent-consumer.html">Idempotent Consumer</a> pattern. 024 * <p/> 025 * The <tt>add</tt> and <tt>contains</tt> methods is operating according to the {@link java.util.Set} contract. 026 * <p/> 027 * The repository supports eager (default) and non-eager mode. 028 * <ul> 029 * <li>eager: calls <tt>add</tt> and <tt>confirm</tt> if complete, or <tt>remove</tt> if failed</li> 030 * <li>non-eager: calls <tt>contains</tt> and <tt>add</tt> if complete, or <tt>remove</tt> if failed</li> 031 * </ul> 032 * Notice the remove callback, can be configured to be disabled. 033 * <p/> 034 * This repository supports the operations to pass in the current exchange, which can be needed by some implementations 035 * such as the JPA idempotent consumer. 036 * 037 * @version 038 */ 039public interface ExchangeIdempotentRepository<E> extends IdempotentRepository<E> { 040 041 /** 042 * Adds the key to the repository. 043 * <p/> 044 * <b>Important:</b> Read the class javadoc about eager vs non-eager mode. 045 * 046 * @param key the key of the message for duplicate test 047 * @return <tt>true</tt> if this repository did <b>not</b> already contain the specified element 048 */ 049 boolean add(Exchange exchange, E key); 050 051 /** 052 * Returns <tt>true</tt> if this repository contains the specified element. 053 * <p/> 054 * <b>Important:</b> Read the class javadoc about eager vs non-eager mode. 055 * 056 * @param key the key of the message 057 * @return <tt>true</tt> if this repository contains the specified element 058 */ 059 boolean contains(Exchange exchange, E key); 060 061 /** 062 * Removes the key from the repository. 063 * <p/> 064 * Is usually invoked if the exchange failed. 065 * <p/> 066 * <b>Important:</b> Read the class javadoc about eager vs non-eager mode. 067 * 068 * @param key the key of the message for duplicate test 069 * @return <tt>true</tt> if the key was removed 070 */ 071 boolean remove(Exchange exchange, E key); 072 073 /** 074 * Confirms the key, after the exchange has been processed successfully. 075 * <p/> 076 * <b>Important:</b> Read the class javadoc about eager vs non-eager mode. 077 * 078 * @param key the key of the message for duplicate test 079 * @return <tt>true</tt> if the key was confirmed 080 */ 081 boolean confirm(Exchange exchange, E key); 082 083}