snmpnsapaddress.java

基于snmp/mib的网络数据获取系统设计与实现

/*
 * SNMP Package
 *
 * Copyright (C) 2004, Jonathan Sevy <[e-mail]>
 *
 * This is free software. Redistribution and use in source and binary forms, with
 * or without modification, are permitted provided that the following conditions
 * are met:
 *
 *  1. Redistributions of source code must retain the above copyright notice, this
 *     list of conditions and the following disclaimer.
 *  2. 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.
 *  3. The name of the author may not be used to endorse or promote products 
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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. IN NO 
 * EVENT SHALL THE AUTHOR 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.
 *
 */


package snmp;


import java.util.*;


/**
*    Defines class for holding physical 6-byte addresses.
*/

public class SNMPNSAPAddress extends SNMPOctetString
{
    // length limited to 6 octets
    
    
    /**
    *    Initialize address to 0.0.0.0.0.0.
    */
    
    public SNMPNSAPAddress()
    {
        tag = SNMPBERCodec.SNMPNSAPADDRESS;
        
        // initialize to 0.0.0.0.0.0
        data = new byte[6];
        for (int i = 0; i < 6; i++)
            data[i] = 0;
    }
    
    
    
    public SNMPNSAPAddress(String string)
        throws SNMPBadValueException
    {
        tag = SNMPBERCodec.SNMPNSAPADDRESS;
        
        data = parseNSAPAddress(string);
    }
    
    
    
    
    /** 
    *    Used to initialize from the BER encoding, as received in a response from 
    *     an SNMP device responding to an SNMPGetRequest, or from a supplied byte array
    *    containing the address components.
    *     @throws SNMPBadValueException Indicates an invalid array supplied: must have length 6.
    */
    
    public SNMPNSAPAddress(byte[] enc)
        throws SNMPBadValueException
    {
        tag = SNMPBERCodec.SNMPNSAPADDRESS;
        
        if (enc.length == 6)
        {
            data = enc;
        }
        else        // wrong size
        {
            throw new SNMPBadValueException(" NSAPAddress: bad BER encoding supplied to set value ");
        }
    }
    
    
    
    /** 
    *    Used to set the value from a byte array containing the address.
    *     @throws SNMPBadValueException Indicates an incorrect object type supplied, or array of
    *    incorrect size.
    */
    
    public void setValue(Object newAddress)
        throws SNMPBadValueException
    {
        if ((newAddress instanceof byte[]) && (((byte[])newAddress).length == 6))
            data = (byte[])newAddress;
        else if (newAddress instanceof String)
        {
            data = parseNSAPAddress((String)newAddress);
        }
        else
            throw new SNMPBadValueException(" NSAPAddress: bad length byte string supplied to set value ");
    }
    
    
    
    
    /** 
    *     Return pretty-printed (dash-separated) address.
    */
    
    public String toString()
    {
        StringBuffer returnStringBuffer = new StringBuffer();
        
        if (data.length > 0)
        {
            int convert = data[0];
            if (convert < 0)
                    convert += 256;
                returnStringBuffer.append(Integer.toHexString(convert));
                    
            for (int i = 1; i < data.length; i++)
            {
                convert = data[i];
                if (convert < 0)
                    convert += 256;
                returnStringBuffer.append("-");
                returnStringBuffer.append(Integer.toHexString(convert));
            }
        }
        
        return returnStringBuffer.toString();
    }
    
    
    
    private byte[] parseNSAPAddress(String addressString)
        throws SNMPBadValueException
    {
        try
        {
            StringTokenizer st = new StringTokenizer(addressString, " .-"); // break on spaces, dots or dashes
            int size = 0;
            
            while (st.hasMoreTokens())
            {
                // figure out how many values are in string
                size++;
                st.nextToken();
            }
            
            if (size != 6)
            {
                throw new SNMPBadValueException(" NSAPAddress: wrong number of components supplied to set value ");
            }
            
            byte[] returnBytes = new byte[size];
            
            st = new StringTokenizer(addressString, " .-");
            
            for (int i = 0; i < size; i++)
            {
                int addressComponent = (Integer.parseInt(st.nextToken(), 16));
                if ((addressComponent < 0) || (addressComponent > 255))
                    throw new SNMPBadValueException(" NSAPAddress: invalid component supplied to set value ");
                returnBytes[i] = (byte)addressComponent;
            }
            
            return returnBytes;
            
        }
        catch (NumberFormatException e)
        {
            throw new SNMPBadValueException(" NSAPAddress: invalid component supplied to set value ");
        }
        
    }
    
    
    
}