Home | History | Annotate | Download | only in header 
      1 /*
      2 * Conditions Of Use
      3 *
      4 * This software was developed by employees of the National Institute of
      5 * Standards and Technology (NIST), an agency of the Federal Government.
      6 * Pursuant to title 15 Untied States Code Section 105, works of NIST
      7 * employees are not subject to copyright protection in the United States
      8 * and are considered to be in the public domain.  As a result, a formal
      9 * license is not needed to use the software.
     10 *
     11 * This software is provided by NIST as a service and is expressly
     12 * provided "AS IS."  NIST MAKES NO WARRANTY OF ANY KIND, EXPRESS, IMPLIED
     13 * OR STATUTORY, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTY OF
     14 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT
     15 * AND DATA ACCURACY.  NIST does not warrant or make any representations
     16 * regarding the use of the software or the results thereof, including but
     17 * not limited to the correctness, accuracy, reliability or usefulness of
     18 * the software.
     19 *
     20 * Permission to use this software is contingent upon your acceptance
     21 * of the terms of this agreement
     22 *
     23 * .
     24 *
     25 */
     26 /*******************************************************************************
     27 * Product of NIST/ITL Advanced Networking Technologies Division (ANTD).        *
     28 *******************************************************************************/
     29 package gov.nist.javax.sip.header;
     30 import javax.sip.header.*;
     31 import javax.sip.InvalidArgumentException;
     32 
     33 /**
     34  * MaxForwards SIPHeader
     35  *
     36  * @version 1.2 $Revision: 1.8 $ $Date: 2009/07/17 18:57:32 $
     37  *
     38  * @author M. Ranganathan   <br/>
     39  * @author Olivier Deruelle <br/>
     40  *
     41  */
     42 public class MaxForwards extends SIPHeader implements MaxForwardsHeader {
     43 
     44     /**
     45      * Comment for <code>serialVersionUID</code>
     46      */
     47     private static final long serialVersionUID = -3096874323347175943L;
     48     /** maxForwards field.
     49      */
     50     protected int maxForwards;
     51 
     52     /** Default constructor.
     53      */
     54     public MaxForwards() {
     55         super(NAME);
     56     }
     57 
     58   public MaxForwards( int m ) throws InvalidArgumentException {
     59         super(NAME);
     60         this.setMaxForwards( m );
     61     }
     62 
     63     /** get the MaxForwards field.
     64      * @return the maxForwards member.
     65      */
     66     public int getMaxForwards() {
     67         return maxForwards;
     68     }
     69 
     70     /**
     71          * Set the maxForwards member
     72          * @param maxForwards maxForwards parameter to set
     73          */
     74     public void setMaxForwards(int maxForwards)
     75         throws InvalidArgumentException {
     76         if (maxForwards < 0 || maxForwards > 255)
     77             throw new InvalidArgumentException(
     78                 "bad max forwards value " + maxForwards);
     79         this.maxForwards = maxForwards;
     80     }
     81 
     82     /**
     83          * Encode into a string.
     84          * @return encoded string.
     85          *
     86          */
     87     public String encodeBody() {
     88         return encodeBody(new StringBuffer()).toString();
     89     }
     90 
     91     protected StringBuffer encodeBody(StringBuffer buffer) {
     92         return buffer.append(maxForwards);
     93     }
     94 
     95     /** Boolean function
     96      * @return true if MaxForwards field reached zero.
     97      */
     98     public boolean hasReachedZero() {
     99         return maxForwards == 0;
    100     }
    101 
    102     /** decrement MaxForwards field one by one.
    103      */
    104     public void decrementMaxForwards() throws TooManyHopsException {
    105         if (maxForwards > 0)
    106             maxForwards--;
    107         else throw new TooManyHopsException ("has already reached 0!");
    108     }
    109 
    110     public boolean equals(Object other) {
    111         if (this==other) return true;
    112         if (other instanceof MaxForwardsHeader) {
    113             final MaxForwardsHeader o = (MaxForwardsHeader) other;
    114             return this.getMaxForwards() == o.getMaxForwards();
    115         }
    116         return false;
    117     }
    118 }
    119