Java example source code file (UserPrincipalLookupService.java)

This example Java source code file (UserPrincipalLookupService.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

groupprincipal, ioexception, userprincipal, userprincipallookupservice

The UserPrincipalLookupService.java Java example source code

/*
 * Copyright (c) 2007, 2009, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package java.nio.file.attribute;

import java.io.IOException;

/**
 * An object to lookup user and group principals by name. A {@link UserPrincipal}
 * represents an identity that may be used to determine access rights to objects
 * in a file system. A {@link GroupPrincipal} represents a <em>group identity.
 * A {@code UserPrincipalLookupService} defines methods to lookup identities by
 * name or group name (which are typically user or account names). Whether names
 * and group names are case sensitive or not depends on the implementation.
 * The exact definition of a group is implementation specific but typically a
 * group represents an identity created for administrative purposes so as to
 * determine the access rights for the members of the group. In particular it is
 * implementation specific if the <em>namespace for names and groups is the
 * same or is distinct. To ensure consistent and correct behavior across
 * platforms it is recommended that this API be used as if the namespaces are
 * distinct. In other words, the {@link #lookupPrincipalByName
 * lookupPrincipalByName} should be used to lookup users, and {@link
 * #lookupPrincipalByGroupName lookupPrincipalByGroupName} should be used to
 * lookup groups.
 *
 * @since 1.7
 *
 * @see java.nio.file.FileSystem#getUserPrincipalLookupService
 */

public abstract class UserPrincipalLookupService {

    /**
     * Initializes a new instance of this class.
     */
    protected UserPrincipalLookupService() {
    }

    /**
     * Lookup a user principal by name.
     *
     * @param   name
     *          the string representation of the user principal to lookup
     *
     * @return  a user principal
     *
     * @throws  UserPrincipalNotFoundException
     *          the principal does not exist
     * @throws  IOException
     *          if an I/O error occurs
     * @throws  SecurityException
     *          In the case of the default provider, and a security manager is
     *          installed, it checks {@link RuntimePermission}<tt>("lookupUserInformation")
     */
    public abstract UserPrincipal lookupPrincipalByName(String name)
        throws IOException;

    /**
     * Lookup a group principal by group name.
     *
     * <p> Where an implementation does not support any notion of group then
     * this method always throws {@link UserPrincipalNotFoundException}. Where
     * the namespace for user accounts and groups is the same, then this method
     * is identical to invoking {@link #lookupPrincipalByName
     * lookupPrincipalByName}.
     *
     * @param   group
     *          the string representation of the group to lookup
     *
     * @return  a group principal
     *
     * @throws  UserPrincipalNotFoundException
     *          the principal does not exist or is not a group
     * @throws  IOException
     *          if an I/O error occurs
     * @throws  SecurityException
     *          In the case of the default provider, and a security manager is
     *          installed, it checks {@link RuntimePermission}<tt>("lookupUserInformation")
     */
    public abstract GroupPrincipal lookupPrincipalByGroupName(String group)
        throws IOException;
}