VFS-2.0-RC1/core/src/main/java/org/apache/commons/vfs/util/UserAuthenticatorUtils.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.vfs.util;

import org.apache.commons.vfs.UserAuthenticator;
import org.apache.commons.vfs.UserAuthenticationData;
import org.apache.commons.vfs.FileSystemOptions;
import org.apache.commons.vfs.impl.DefaultFileSystemConfigBuilder;

/**
 * Some helper methods used for authentication.
 * @author <a href="http://commons.apache.org/vfs/team-list.html">Commons VFS team</a>
 */
public final class UserAuthenticatorUtils
{
    private UserAuthenticatorUtils()
    {
    }

    /**
     * gets data of given type from the UserAuthenticationData or null if there is no data or data
     * of this type available.
     * @param data The UserAuthenticationData.
     * @param type The type of the element to retrieve.
     * @param overriddenValue The default value.
     * @return The data of the given type as a character array or null if the data is not available.
     */
    public static char[] getData(UserAuthenticationData data, UserAuthenticationData.Type type,
                                 char[] overriddenValue)
    {
        if (overriddenValue != null)
        {
            return overriddenValue;
        }

        if (data == null)
        {
            return null;
        }

        return data.getData(type);
    }

    /**
     * if there is a authenticator the authentication will take place, else null will be reutrned.
     * @param opts The FileSystemOptions.
     * @param authenticatorTypes An array of types describing the data to be retrieved.
     * @return A UserAuthenticationData object containing the data requested.
     */
    public static UserAuthenticationData authenticate(FileSystemOptions opts,
                                                      UserAuthenticationData.Type[] authenticatorTypes)
    {
        UserAuthenticator auth = DefaultFileSystemConfigBuilder.getInstance().getUserAuthenticator(opts);
        return authenticate(auth, authenticatorTypes);
    }

    /**
     * if there is a authenticator the authentication will take place, else null will be reutrned.
     * @param auth The UserAuthenticator.
     * @param authenticatorTypes An array of types describing the data to be retrieved.
     * @return A UserAuthenticationData object containing the data requested.
     */
    public static UserAuthenticationData authenticate(UserAuthenticator auth,
                                                      UserAuthenticationData.Type[] authenticatorTypes)
    {
        if (auth == null)
        {
            return null;
        }

        return auth.requestAuthentication(authenticatorTypes);
    }

    /**
     * Converts a string to a char array (null safe).
     * @param string The String to convert.
     * @return The character array.
     */
    public static char[] toChar(String string)
    {
        if (string == null)
        {
            return null;
        }

        return string.toCharArray();
    }

    /**
     * cleanup the data in the UerAuthenticationData (null safe).
     * @param authData The UserAuthenticationDAta.
     */
    public static void cleanup(UserAuthenticationData authData)
    {
        if (authData == null)
        {
            return;
        }

        authData.cleanup();
    }

    /**
     * converts the given data to a string (null safe).
     * @param data A character array containing the data to convert to a String.
     * @return The String.
     */
    public static String toString(char[] data)
    {
        if (data == null)
        {
            return null;
        }

        return new String(data);
    }
}