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 * 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.

 *

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package javax.security.auth.callback;

/**

 * <p> Underlying security services instantiate and pass a

 * {@code PasswordCallback} to the {@code handle}

 * method of a {@code CallbackHandler} to retrieve password information.

 *

 * @since 1.4

 * @see javax.security.auth.callback.CallbackHandler

 */

public class PasswordCallback implements Callback, java.io.Serializable {

    private static final long serialVersionUID = 2267422647454909926L;

    /**

     * @serial

     * @since 1.4

     */

    private String prompt;

    /**

     * @serial

     * @since 1.4

     */

    private boolean echoOn;

    /**

     * @serial

     * @since 1.4

     */

    private char[] inputPassword;

    /**

     * Construct a {@code PasswordCallback} with a prompt

     * and a boolean specifying whether the password should be displayed

     * as it is being typed.

     *

     * @param prompt the prompt used to request the password.

     *

     * @param echoOn true if the password should be displayed

     *                  as it is being typed.

     *

     * @exception IllegalArgumentException if {@code prompt} is null or

     *                  if {@code prompt} has a length of 0.

     */

    public PasswordCallback(String prompt, boolean echoOn) {

        if (prompt == null || prompt.isEmpty())

            throw new IllegalArgumentException();

        this.prompt = prompt;

        this.echoOn = echoOn;

    }

    /**

     * Get the prompt.

     *

     * @return the prompt.

     */

    public String getPrompt() {

        return prompt;

    }

    /**

     * Return whether the password

     * should be displayed as it is being typed.

     *

     * @return the whether the password

     *          should be displayed as it is being typed.

     */

    public boolean isEchoOn() {

        return echoOn;

    }

    /**

     * Set the retrieved password.

     *

     * <p> This method makes a copy of the input {@code password}

     * before storing it.

     *

     * @param password the retrieved password, which may be null.

     *

     * @see #getPassword

     */

    public void setPassword(char[] password) {

        this.inputPassword = (password == null ? null : password.clone());

    }

    /**

     * Get the retrieved password.

     *

     * <p> This method returns a copy of the retrieved password.

     *

     * @return the retrieved password, which may be null.

     *

     * @see #setPassword

     */

    public char[] getPassword() {

        return (inputPassword == null ? null : inputPassword.clone());

    }

    /**

     * Clear the retrieved password.

     */

    public void clearPassword() {

        if (inputPassword != null) {

            for (int i = 0; i < inputPassword.length; i++)

                inputPassword[i] = ' ';

        }

    }

}