time.java

一个完整的XACML工程,学习XACML技术的好例子!

/*
* Copyright (c) 2000-2005, University of Salford
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without 
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* Redistributions of source code must retain the above copyright notice, this 
* list of conditions and the following disclaimer.
* 
* Redistributions in binary form must reproduce the above copyright notice, 
* this list of conditions and the following disclaimer in the documentation 
* and/or other materials provided with the distribution. 
*
* Neither the name of the University of Salford nor the names of its 
* contributors may be used to endorse or promote products derived from this 
* software without specific prior written permission. 
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
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package issrg.pba.rbac;

/**
 * This is an extension for evaluating Time expressions in the XML Policy.
 *
 * <p>The Policy must contain Const values of type "Time". The values must 
 * conform to the
 * following syntax: "ccyy-mm-ddThh:mm:ss" (like in Validity elements in XML 
 * Policy). Thus 
 * the time can be specified up to the seconds.
 * The year should always have 4 digits. Other fields do not need to have 2 
 * digits, if they represent
 * numbers less than 10. "*" asterisc can be used as a wildcard to represent
 * "any value" at that position. Trailing fields can be omitted and their 
 * values will be considered 0.
 *
 * <p>Examples:
 * <p><code>&lt;Constant Type="Time" Value="*-*-*T8:20" /&gt;</code>
 * <p>The example matches 08:20:00 in the morning any day
 * <p><code>&lt;Constant Type="Time" Value="*-*-*T8:20:*" /&gt;</code>
 * <p>The above matches any second after 08:20:00 and before 08:21:00 in the 
 * morning any day. This is
 * different from the above example in that it matches ANY second, i.e. the 
 * whole minute up to 8:21, whilst
 * the previous example specifies exact time of day (8:20:00).
 * <p><code>&lt;Constant Type="Time" Value="*-1-*T20" /&gt;</code>
 * <p>This example matches 8pm any day throughout January.
 * <p><code>&lt;Constant Type="Time" Value="*-1" /&gt;</code>
 * <p>This example matches midnight any day through January.
 *
 * <p>The extension has been provided in PBA v1.1.
 */

public class Time {
  public static final String TIME_TYPE="Time";

  private final int [] time=new int[]{-1, -1, -1,
              // -1, // the fourth was for the weekday
				-1, -1, -1};

  public static void register(){
    issrg.pba.rbac.xmlpolicy
    .ifstatement.Types.registerType(TIME_TYPE, Time.class);
  }

  protected Time(){}

  /**
   * This constructor builds a Time object out of its string representation
   * 
   * @param timeString - the String in the format explained above.
   */
  public Time(String timeString) throws IllegalArgumentException {
    String d="--T::\""; // the last character is always there to ensure that the last number is parsed, too
    String s;
    int i;

    for (int j=0; j<d.length(); j++){
      s=timeString;
      i=timeString.indexOf(d.charAt(j));
      if (i>=0){
        s=timeString.substring(0, i);
        timeString=timeString.substring(i+1);
      }else{
        timeString=""; // that's it, since no more delimiters found, no more time components are there
      }

      try{
        time[j]=s.intern()=="*"?-1:s.intern()==""?0:Integer.parseInt(s);
      }catch (NumberFormatException nfe){
        throw new IllegalArgumentException("Date format error: "+nfe.getMessage());
      }
    }
	//System.out.println("parsed time: "+time[0]+"."+time[1]+"."+time[2]+", "+time[3]+":"+time[4]+":"+time[5]);//*************

  }

  /**
    * Returns an array of integers representing the year, month, day
    * hour, minute, second. If the value of the array element
    * is -1, then the value is not specified ("don't care" when comparing)
    *
    * @return array of integers, each element standing for y,m,d,h,m,s
    */
  public int [] getEvaluationTime(){
    return time;
  }
}