1 /* 2 * Copyright (c) 2007, 2009, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.nio.file.attribute; 27 28 import java.io.IOException; 29 30 /** 31 * An object to lookup user and group principals by name. A {@link UserPrincipal} 32 * represents an identity that may be used to determine access rights to objects 33 * in a file system. A {@link GroupPrincipal} represents a <em>group identity</em>. 34 * A {@code UserPrincipalLookupService} defines methods to lookup identities by 35 * name or group name (which are typically user or account names). Whether names 36 * and group names are case sensitive or not depends on the implementation. 37 * The exact definition of a group is implementation specific but typically a 38 * group represents an identity created for administrative purposes so as to 39 * determine the access rights for the members of the group. In particular it is 40 * implementation specific if the <em>namespace</em> for names and groups is the 41 * same or is distinct. To ensure consistent and correct behavior across 42 * platforms it is recommended that this API be used as if the namespaces are 43 * distinct. In other words, the {@link #lookupPrincipalByName 44 * lookupPrincipalByName} should be used to lookup users, and {@link 45 * #lookupPrincipalByGroupName lookupPrincipalByGroupName} should be used to 46 * lookup groups. 47 * 48 * @since 1.7 49 * 50 * @see java.nio.file.FileSystem#getUserPrincipalLookupService 51 */ 52 53 public abstract class UserPrincipalLookupService { 54 55 /** 56 * Initializes a new instance of this class. 57 */ UserPrincipalLookupService()58 protected UserPrincipalLookupService() { 59 } 60 61 /** 62 * Lookup a user principal by name. 63 * 64 * @param name 65 * the string representation of the user principal to lookup 66 * 67 * @return a user principal 68 * 69 * @throws UserPrincipalNotFoundException 70 * the principal does not exist 71 * @throws IOException 72 * if an I/O error occurs 73 * @throws SecurityException 74 * In the case of the default provider, and a security manager is 75 * installed, it checks 76 * {@link RuntimePermission}{@code ("lookupUserInformation")} 77 */ lookupPrincipalByName(String name)78 public abstract UserPrincipal lookupPrincipalByName(String name) 79 throws IOException; 80 81 /** 82 * Lookup a group principal by group name. 83 * 84 * <p> Where an implementation does not support any notion of group then 85 * this method always throws {@link UserPrincipalNotFoundException}. Where 86 * the namespace for user accounts and groups is the same, then this method 87 * is identical to invoking {@link #lookupPrincipalByName 88 * lookupPrincipalByName}. 89 * 90 * @param group 91 * the string representation of the group to lookup 92 * 93 * @return a group principal 94 * 95 * @throws UserPrincipalNotFoundException 96 * the principal does not exist or is not a group 97 * @throws IOException 98 * if an I/O error occurs 99 * @throws SecurityException 100 * In the case of the default provider, and a security manager is 101 * installed, it checks 102 * {@link RuntimePermission}{@code ("lookupUserInformation")} 103 */ lookupPrincipalByGroupName(String group)104 public abstract GroupPrincipal lookupPrincipalByGroupName(String group) 105 throws IOException; 106 } 107