1 /* 2 * The contents of this file are subject to the terms 3 * of the Common Development and Distribution License 4 * (the License). You may not use this file except in 5 * compliance with the License. 6 * 7 * You can obtain a copy of the license at 8 * https://glassfish.dev.java.net/public/CDDLv1.0.html or 9 * glassfish/bootstrap/legal/CDDLv1.0.txt. 10 * See the License for the specific language governing 11 * permissions and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL 14 * Header Notice in each file and include the License file 15 * at glassfish/bootstrap/legal/CDDLv1.0.txt. 16 * If applicable, add the following below the CDDL Header, 17 * with the fields enclosed by brackets [] replaced by 18 * you own identifying information: 19 * "Portions Copyrighted [year] [name of copyright owner]" 20 * 21 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 22 */ 23 24 25 package javax.jms; 26 27 /** The delivery modes supported by the JMS API are <CODE>PERSISTENT</CODE> and 28 * <CODE>NON_PERSISTENT</CODE>. 29 * 30 * <P>A client marks a message as persistent if it feels that the 31 * application will have problems if the message is lost in transit. 32 * A client marks a message as non-persistent if an occasional 33 * lost message is tolerable. Clients use delivery mode to tell a 34 * JMS provider how to balance message transport reliability with throughput. 35 * 36 * <P>Delivery mode covers only the transport of the message to its 37 * destination. Retention of a message at the destination until 38 * its receipt is acknowledged is not guaranteed by a <CODE>PERSISTENT</CODE> 39 * delivery mode. Clients should assume that message retention 40 * policies are set administratively. Message retention policy 41 * governs the reliability of message delivery from destination 42 * to message consumer. For example, if a client's message storage 43 * space is exhausted, some messages may be dropped in accordance with 44 * a site-specific message retention policy. 45 * 46 * <P>A message is guaranteed to be delivered once and only once 47 * by a JMS provider if the delivery mode of the message is 48 * <CODE>PERSISTENT</CODE> 49 * and if the destination has a sufficient message retention policy. 50 * 51 * 52 * 53 * @version 1.0 - 7 August 1998 54 * @author Mark Hapner 55 * @author Rich Burridge 56 */ 57 58 public interface DeliveryMode { 59 60 /** This is the lowest-overhead delivery mode because it does not require 61 * that the message be logged to stable storage. The level of JMS provider 62 * failure that causes a <CODE>NON_PERSISTENT</CODE> message to be lost is 63 * not defined. 64 * 65 * <P>A JMS provider must deliver a <CODE>NON_PERSISTENT</CODE> message 66 * with an 67 * at-most-once guarantee. This means that it may lose the message, but it 68 * must not deliver it twice. 69 */ 70 71 static final int NON_PERSISTENT = 1; 72 73 /** This delivery mode instructs the JMS provider to log the message to stable 74 * storage as part of the client's send operation. Only a hard media 75 * failure should cause a <CODE>PERSISTENT</CODE> message to be lost. 76 */ 77 78 static final int PERSISTENT = 2; 79 } 80