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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * 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 sun.security.action;

import java.security.AccessController;

import java.security.PrivilegedAction;

/**

 * A convenience class for retrieving the string value of a system

 * property as a privileged action.

 *

 * <p>An instance of this class can be used as the argument of

 * <code>AccessController.doPrivileged</code>.

 *

 * <p>The following code retrieves the value of the system

 * property named <code>"prop"</code> as a privileged action: <p>

 *

 * <pre>

 * String s = java.security.AccessController.doPrivileged

 *                      (new GetPropertyAction("prop"));

 * </pre>

 *

 * @author Roland Schemers

 * @see java.security.PrivilegedAction

 * @see java.security.AccessController

 * @since 1.2

 */

public class GetPropertyAction implements PrivilegedAction<String> {

    private String theProp;

    private String defaultVal;

    /**

     * Constructor that takes the name of the system property whose

     * string value needs to be determined.

     *

     * @param theProp the name of the system property.

     */

    public GetPropertyAction(String theProp) {

        this.theProp = theProp;

    }

    /**

     * Constructor that takes the name of the system property and the default

     * value of that property.

     *

     * @param theProp the name of the system property.

     * @param defaulVal the default value.

     */

    public GetPropertyAction(String theProp, String defaultVal) {

        this.theProp = theProp;

        this.defaultVal = defaultVal;

    }

    /**

     * Determines the string value of the system property whose

     * name was specified in the constructor.

     *

     * @return the string value of the system property,

     *         or the default value if there is no property with that key.

     */

    public String run() {

        String value = System.getProperty(theProp);

        return (value == null) ? defaultVal : value;

    }

    /**

     * Convenience method to get a property without going through doPrivileged

     * if no security manager is present. This is unsafe for inclusion in a

     * public API but allowable here since this class is by default restricted

     * by the package.access security property.

     *

     * Note that this method performs a privileged action using caller-provided

     * inputs. The caller of this method should take care to ensure that the

     * inputs are not tainted and the returned property is not made accessible

     * to untrusted code if it contains sensitive information.

     *

     * @param theProp the name of the system property.

     */

    public static String privilegedGetProperty(String theProp) {

        if (System.getSecurityManager() == null) {

            return System.getProperty(theProp);

        } else {

            return AccessController.doPrivileged(

                    new GetPropertyAction(theProp));

        }

    }

    /**

     * Convenience method to get a property without going through doPrivileged

     * if no security manager is present. This is unsafe for inclusion in a

     * public API but allowable here since this class is now encapsulated.

     *

     * Note that this method performs a privileged action using caller-provided

     * inputs. The caller of this method should take care to ensure that the

     * inputs are not tainted and the returned property is not made accessible

     * to untrusted code if it contains sensitive information.

     *

     * @param theProp the name of the system property.

     * @param defaultVal the default value.

     */

    public static String privilegedGetProperty(String theProp,

            String defaultVal) {

        if (System.getSecurityManager() == null) {

            return System.getProperty(theProp, defaultVal);

        } else {

            return AccessController.doPrivileged(

                    new GetPropertyAction(theProp, defaultVal));

        }

    }

}