BEGIN LICENSE BLOCK *****
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Software distributed under the License is distributed on an "AS
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implied. See the License for the specific language governing
rights and limitations under the License.
Copyright (C) 2007 Vladimir Sizikov 
Alternatively, the contents of this file may be used under the terms of
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 * Version: EPL 2.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Eclipse Public
 * License Version 2.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
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 *
 * Software distributed under the License is distributed on an "AS
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 * Copyright (C) 2007 Vladimir Sizikov <vsizikov@gmail.com>
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 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the EPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
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package org.jruby.util;

import java.util.Map;

Utility class to safely access system properties in security-sensitive
environments.
/**
 * Utility class to safely access system properties in security-sensitive
 * environments.
 */
public class SafePropertyAccessor {

    
An extension over Boolean.getBoolean method.
Returns true if and only if the system property
named by the argument exists and is equal to the string "true".
If there is no property with the specified name, or if the specified
name is empty or null, or if the access to the property is
restricted, then false is returned.
Params:
property – The system property name.
Returns:
The boolean value of the system property./**
     * An extension over <code>Boolean.getBoolean</code> method.
     * Returns true if and only if the system property
     * named by the argument exists and is equal to the string "true".
     * If there is no property with the specified name, or if the specified
     * name is empty or null, or if the access to the property is
     * restricted, then false is returned.
     * @param property The system property name.
     * @return The boolean value of the system property.
     */
    public static boolean getBoolean(String property) {
        try {
            return Boolean.getBoolean(property);
        } catch (SecurityException se) {
            return false;
        }
    }

    
An extension over Boolean.getBoolean method.
Handles security restrictions, and provides default value
in case when access to the property is restricted,
of when the property does not exist.
Params:
property – The system property name.
defValue – The default value.
Returns:
The boolean value of the system property,
        or the default value./**
     * An extension over <code>Boolean.getBoolean</code> method.
     * Handles security restrictions, and provides default value
     * in case when access to the property is restricted,
     * of when the property does not exist.
     * @param property The system property name.
     * @param defValue The default value.
     * @return The boolean value of the system property,
     *         or the default value.
     */
    public static boolean getBoolean(String property, boolean defValue) {
        try {
            if (System.getProperty(property) != null) {
                return Boolean.getBoolean(property);
            } else {
                return defValue;
            }
        } catch (SecurityException se) {
            return defValue;
        }
    }

    
An extension over System.getProperty method.
Handles security restrictions, and returns null
if the access to the property is restricted.
Params:
property – The system property name.
Returns:
The value of the system property,
        or the default value./**
     * An extension over <code>System.getProperty</code> method.
     * Handles security restrictions, and returns <code>null</code>
     * if the access to the property is restricted.
     * @param property The system property name.
     * @return The value of the system property,
     *         or the default value.
     */
    public static String getProperty(String property) {
        return getProperty(property, null);
    }

    
An extension over System.getProperty method.
Handles security restrictions, and returns the default
value if the access to the property is restricted.
Params:
property – The system property name.
defValue – The default value.
Returns:
The value of the system property,
        or the default value./**
     * An extension over <code>System.getProperty</code> method.
     * Handles security restrictions, and returns the default
     * value if the access to the property is restricted.
     * @param property The system property name.
     * @param defValue The default value.
     * @return The value of the system property,
     *         or the default value.
     */
    public static String getProperty(String property, String defValue) {
        try {
            return System.getProperty(property, defValue);
        } catch (SecurityException se) {
            return defValue;
        }
    }

    
An extension over System.getProperty method
that additionally produces an int value.
Handles security restrictions, and returns 0
if the access to the property is restricted.
Params:
property – The system property name.
Returns:
The value of the system property,
        or the default value./**
     * An extension over <code>System.getProperty</code> method
     * that additionally produces an int value.
     * Handles security restrictions, and returns <code>0</code>
     * if the access to the property is restricted.
     * @param property The system property name.
     * @return The value of the system property,
     *         or the default value.
     */
    public static int getInt(String property) {
        return getInt(property, 0);
    }

    
An extension over System.getProperty method
that additionally produces an int value.
Handles security restrictions, and returns the default
value if the access to the property is restricted.
Params:
property – The system property name.
defValue – The default value.
Returns:
The value of the system property,
        or the default value./**
     * An extension over <code>System.getProperty</code> method
     * that additionally produces an int value.
     * Handles security restrictions, and returns the default
     * value if the access to the property is restricted.
     * @param property The system property name.
     * @param defValue The default value.
     * @return The value of the system property,
     *         or the default value.
     */
    public static int getInt(String property, int defValue) {
        try {
            return Integer.parseInt(System.getProperty(property, String.valueOf(defValue)));
        } catch (SecurityException se) {
            return defValue;
        }
    }

    
Returns true if the access to the system property
is restricted (i.e., when System.getProperty()
throws SecurityException).
Params:
property – The system property name.
Returns:
true if the access is restricted,
        false otherwise./**
     * Returns <code>true</code> if the access to the system property
     * is restricted (i.e., when System.getProperty()
     * throws SecurityException).
     * @param property The system property name.
     * @return <code>true</code> if the access is restricted,
     *         <code>false</code> otherwise.
     */
    public static boolean isSecurityProtected(String property) {
        try {
            System.getProperty(property);
            return false;
        } catch (SecurityException se) {
            return true;
        }
    }
    
    
An extension over System.getenv method.
Handles security restrictions, and returns null
if the access to the environment variable is restricted.
Params:
name – The environment variable name.
Returns:
The value of the environment variable,
        or null./**
     * An extension over <code>System.getenv</code> method.
     * Handles security restrictions, and returns <code>null</code>
     * if the access to the environment variable is restricted.
     * @param name The environment variable name.
     * @return The value of the environment variable,
     *         or null.
     */
    public static String getenv(String name) {
        try {
            return System.getenv(name);
        } catch (SecurityException se) {
            return null;
        }
    }
    
    
An extension over System.getenv method.
Handles security restrictions, and returns null
if the access to the environment map is restricted.
Returns:
The map of the environment variables,
        or null./**
     * An extension over <code>System.getenv</code> method.
     * Handles security restrictions, and returns <code>null</code>
     * if the access to the environment map is restricted.
     * @return The map of the environment variables,
     *         or null.
     */
    public static Map<String,String> getenv() {
        try {
            return System.getenv();
        } catch (SecurityException se) {
            return null;
        }
    }
}