# PropsWorker.java

    /*
    ** Module   : PropsWorker.java
    ** Abstract : provides functions for accessing J2SE system properties
    **
    ** Copyright (c) 2005-2022, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- -T- --JPRM-- ----------------Description-----------------
    ** 001 GES 20050228 NEW   @20118 Created initial version supporting a simple
    **                               query mechanism that is data type specific.
    **                               There is also a function that allows the
    **                               caller to check if a named property exists.
    ** 002 ECF 20050303 CHG   @20169 Replaced getIntegerProperty with
    **                               getLongProperty, since Integer return types
    **                               are not supported by the expression engine.
    ** 003 ECF 20050526 CHG   @21290 Changes to support new expression engine
    **                               implementation. Changed library registration
    **                               mechanism based on superclass' modifications
    **                               to support single library per pattern worker
    **                               limit.
    ** 004 EVL 20160223              Javadoc fixes to make compatible with Oracle Java 8 for
    **                               Solaris 10.
    ** 005 TJD 20220504              Upgrade do Java 11 minor changes
    */
    /*
    ** This program is free software: you can redistribute it and/or modify
    ** it under the terms of the GNU Affero General Public License as
    ** published by the Free Software Foundation, either version 3 of the
    ** License, or (at your option) any later version.
    **
    ** This program 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 Affero General Public License for more details.
    **
    ** You may find a copy of the GNU Affero GPL version 3 at the following
    ** location: https://www.gnu.org/licenses/agpl-3.0.en.html
    **
    ** Additional terms under GNU Affero GPL version 3 section 7:
    **
    **   Under Section 7 of the GNU Affero GPL version 3, the following additional
    **   terms apply to the works covered under the License.  These additional terms
    **   are non-permissive additional terms allowed under Section 7 of the GNU
    **   Affero GPL version 3 and may not be removed by you.
    **
    **   0. Attribution Requirement.
    **
    **     You must preserve all legal notices or author attributions in the covered
    **     work or Appropriate Legal Notices displayed by works containing the covered
    **     work.  You may not remove from the covered work any author or developer
    **     credit already included within the covered work.
    **
    **   1. No License To Use Trademarks.
    **
    **     This license does not grant any license or rights to use the trademarks
    **     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
    **     of Golden Code Development Corporation. You are not authorized to use the
    **     name Golden Code, FWD, or the names of any author or contributor, for
    **     publicity purposes without written authorization.
    **
    **   2. No Misrepresentation of Affiliation.
    **
    **     You may not represent yourself as Golden Code Development Corporation or FWD.
    **
    **     You may not represent yourself for publicity purposes as associated with
    **     Golden Code Development Corporation, FWD, or any author or contributor to
    **     the covered work, without written authorization.
    **
    **   3. No Misrepresentation of Source or Origin.
    **
    **     You may not represent the covered work as solely your work.  All modified
    **     versions of the covered work must be marked in a reasonable way to make it
    **     clear that the modified work is not originating from Golden Code Development
    **     Corporation or FWD.  All modified versions must contain the notices of
    **     attribution required in this license.
    */

    package com.goldencode.p2j.pattern;

    /**
     * Provides a set of user-defined functions for accessing system properties.
     *
     * @author    GES
     * @version   1.0.1
     */
    public class PropsWorker
    extends AbstractPatternWorker
    {
       /**
        * Default constructor which calls the super constructor and registers
        * libraries with the pattern engine.
        */
       public PropsWorker()
       {
          super();
          setLibrary(new Props());
       }

       /**
        * This is a pattern engine library that provides easy access to system
        * properties.
        */
       public class Props
       {
          /**
           * Determines if a named system property exists or not.
           *
           * @param    prop
           *           The system property to lookup.
           *
           * @return   <code>true</code> if a system property of the specified
           *           name exists, <code>false</code> otherwise.
           */
          public boolean isProperty(String prop)
          {
             return (System.getProperty(prop) != null);
          }

          /**
           * Return a named system property as a string value.
           *
           * @param    prop
           *           The system property to lookup.
           *
           * @return   The value of the system property or <code>null</code> if
           *           no such property exists.
           */
          public String getStringProperty(String prop)
          {
             return System.getProperty(prop);
          }

          /**
           * Return a named system property as a <code>Double</code> value.
           *
           * @param    prop
           *           The system property to lookup.
           *
           * @return   The value of the system property or <code>null</code> if
           *           no such property exists.
           */
          public Double getDoubleProperty(String prop)
          throws NumberFormatException
          {
             String ddd = System.getProperty(prop);

             if (ddd == null)
                return null;

             return Double.valueOf(ddd);
          }

          /**
           * Return a named system property as a <code>Long</code> value.
           *
           * @param    prop
           *           The system property to lookup.
           *
           * @return   The value of the system property or <code>null</code> if
           *           no such property exists.
           */
          public Long getLongProperty(String prop)
          throws NumberFormatException
          {
             String lll = System.getProperty(prop);

             if (lll == null)
                return null;

             return Long.valueOf(lll);
          }

          /**
           * Return a named system property as a <code>Boolean</code> value.
           *
           * @param    prop
           *           The system property to lookup.
           *
           * @return   The value of the system property or <code>null</code> if
           *           no such property exists.
           */
          public Boolean getBooleanProperty(String prop)
          throws NumberFormatException
          {
             String bbb = System.getProperty(prop);

             if (bbb == null)
                return null;

             return Boolean.valueOf(bbb);
          }
       }
    }