Java example source code file (GetPropertyAction.java)

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Java - Java tags/keywords

getpropertyaction, object, string

The GetPropertyAction.java Java example source code

/*
 * Copyright (c) 2004, 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 com.sun.corba.se.impl.orbutil ;

/**
 * A convenience class for retrieving the string value of a system
 * property as a privileged action.  This class is directly copied
 * from sun.security.action.GetPropertyAction in order to avoid
 * depending on the sun.security.action package.
 *
 * <p>An instance of this class can be used as the argument of
 * <code>AccessController.doPrivileged.
 *
 * <p>The following code retrieves the value of the system
 * property named <code>"prop" as a privileged action: 

 *
 * <pre>
 * String s = (String) java.security.AccessController.doPrivileged(
 *                         new GetPropertyAction("prop"));
 * </pre>
 *
 * @author Roland Schemers
 * @author Ken Cavanaugh
 * @see java.security.PrivilegedAction
 * @see java.security.AccessController
 */

public class GetPropertyAction implements java.security.PrivilegedAction {
    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 Object run() {
        String value = System.getProperty(theProp);
        return (value == null) ? defaultVal : value;
    }
}