escapedstringtokenizer.java

一个完整的XACML工程,学习XACML技术的好例子!

/*
 * EscapedStringTokenizer.java
 *
 * Created on 2006/12/16, 5:41pm
 *
 * Copyright (c) 2006, University of Kent
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 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.
 *
 * 1. Neither the name of the University of Kent nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * 2. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.
 *
 * 3. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * 4. YOU AGREE THAT THE EXCLUSIONS IN PARAGRAPHS 2 AND 3 ABOVE ARE REASONABLE
 * IN THE CIRCUMSTANCES.  IN PARTICULAR, YOU ACKNOWLEDGE (1) THAT THIS
 * SOFTWARE HAS BEEN MADE AVAILABLE TO YOU FREE OF CHARGE, (2) THAT THIS
 * SOFTWARE IS NOT "PRODUCT" QUALITY, BUT HAS BEEN PRODUCED BY A RESEARCH
 * GROUP WHO DESIRE TO MAKE THIS SOFTWARE FREELY AVAILABLE TO PEOPLE WHO WISH
 * TO USE IT, AND (3) THAT BECAUSE THIS SOFTWARE IS NOT OF "PRODUCT" QUALITY
 * IT IS INEVITABLE THAT THERE WILL BE BUGS AND ERRORS, AND POSSIBLY MORE
 * SERIOUS FAULTS, IN THIS SOFTWARE.
 *
 * 5. This license is governed, except to the extent that local laws
 * necessarily apply, by the laws of England and Wales.
 *
 * Author : Gansen Zhao
 * Email: [e-mail]
 *
 */

package issrg.pba.rbac.xmlpolicy;

import java.util.Enumeration;

/**
 *
 * @author gansen
 */
public class EscapedStringTokenizer implements Enumeration{
    
    String m_str;
    char m_delim;
    int m_curpos;
    /** Creates a new instance of EscapedStringTokenizer */
    public EscapedStringTokenizer(String strTobeSplit, char delim) {
        m_str=strTobeSplit;
        m_delim=delim;
        m_curpos=0;
    }

    private int nextDelimPosition(){
        
        
        boolean bIsOddAppearance=false;
        boolean bNonDelim=false;
        
        //check from current position to find the next delim.
        for(int i=m_curpos;i<m_str.length();i++)
            if(m_str.charAt(i)==m_delim){
                bIsOddAppearance=!bIsOddAppearance;
            }else if(bIsOddAppearance==true){
                // we have found a odd number of delims, and its's also the end of the delim sequences
                //thus the current position is the end.
                return i;
            }        
            return m_str.length();
    }
    
    public boolean hasMoreElements() {
        
        int i =0;
        i = this.nextDelimPosition();
        if(i>this.m_curpos)
            return true;
        return false;
    }

    public Object nextElement() {
        
        Object obj=null;
        boolean bIsOddAppearance=false;
        
        int next = this.nextDelimPosition();
        
        String nextE="";
        
        for(int i = this.m_curpos; i<next; i++){
            if(m_str.charAt(i)!=m_delim)
                nextE=nextE+m_str.charAt(i);
            else{
                bIsOddAppearance=!bIsOddAppearance;
                if(bIsOddAppearance==false)
                    nextE=nextE+m_str.charAt(i);
            }
            }
        
        this.m_curpos=next;
        return obj=nextE;
        
        }
        

    
}