1 /* 2 * $Id$ 3 * 4 * Licensed to the Apache Software Foundation (ASF) under one 5 * or more contributor license agreements. See the NOTICE file 6 * distributed with this work for additional information 7 * regarding copyright ownership. The ASF licenses this file 8 * to you under the Apache License, Version 2.0 (the 9 * "License"); you may not use this file except in compliance 10 * with the License. You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, 15 * software distributed under the License is distributed on an 16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 17 * KIND, either express or implied. See the License for the 18 * specific language governing permissions and limitations 19 * under the License. 20 */ 21 22 23 package org.apache.struts.apps.mailreader.dao; 24 25 26 /** 27 * <p>A <strong>Data Access Object</strong> (DAO) interface describing 28 * the available operations for retrieving and storing {@link User}s 29 * (and their associated {@link Subscription}s) in some persistence layer 30 * whose characteristics are not specified here. One or more implementations 31 * will be created to perform the actual I/O that is required.</p> 32 * 33 * @author Craig R. McClanahan 34 * @version $Rev$ $Date$ 35 * @since Struts 1.1 36 */ 37 38 public interface UserDatabase { 39 40 41 // --------------------------------------------------------- Public Methods 42 43 44 /** 45 * <p>Create and return a new {@link User} defined in this user database. 46 * </p> 47 * 48 * @param username Username of the new user 49 * 50 * @exception IllegalArgumentException if the specified username 51 * is not unique 52 */ 53 public User createUser(String username); 54 55 56 /** 57 * <p>Finalize access to the underlying persistence layer.</p> 58 * 59 * @exception Exception if a database access error occurs 60 */ 61 public void close() throws Exception; 62 63 64 /** 65 * <p>Return the existing {@link User} with the specified username, 66 * if any; otherwise return <code>null</code>.</p> 67 * 68 * @param username Username of the user to retrieve 69 * @throws ExpiredPasswordException if user password has expired 70 * and must be changed 71 */ 72 public User findUser(String username) throws ExpiredPasswordException; 73 74 75 /** 76 * <p>Return the set of {@link User}s defined in this user database.</p> 77 */ 78 public User[] findUsers(); 79 80 81 /** 82 * <p>Return true if open() has been called.</p> 83 * 84 * @exception Exception if a database access error occurs 85 */ 86 public boolean isOpen(); 87 88 89 /** 90 * <p>Initiate access to the underlying persistence layer.</p> 91 * 92 * @exception Exception if a database access error occurs 93 */ 94 public void open() throws Exception; 95 96 97 /** 98 * Remove the specified {@link User} from this database. 99 * 100 * @param user User to be removed 101 * 102 * @exception IllegalArgumentException if the specified user is not 103 * associated with this database 104 */ 105 public void removeUser(User user); 106 107 108 /** 109 * <p>Save any pending changes to the underlying persistence layer.</p> 110 * 111 * @exception Exception if a database access error occurs 112 */ 113 public void save() throws Exception; 114 115 116 }