/*
 * @(#)file      SnmpPdu.java
 * @(#)author    Sun Microsystems, Inc.
 * @(#)version   1.10
 * @(#)date      06/05/03
 *
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 */
package com.sun.jmx.snmp;


import java.io.Serializable;
import java.net.InetAddress;
/**
 * Is the fully decoded representation of an SNMP packet.
 * <P>
 * Classes are derived from <CODE>SnmpPdu</CODE> to
 * represent the different forms of SNMP packets
 * ({@link com.sun.jmx.snmp.SnmpPduPacket SnmpPduPacket},
 * {@link com.sun.jmx.snmp.SnmpScopedPduPacket SnmpScopedPduPacket})
 * <BR>The <CODE>SnmpPdu</CODE> class defines the attributes 
 * common to every form of SNMP packets.
 * 
 * 
 * <p><b>This API is a Sun Microsystems internal API  and is subject 
 * to change without notice.</b></p>
 * @see SnmpMessage
 * @see SnmpPduFactory
 *
 * @since 1.5
 */
public abstract class SnmpPdu implements SnmpDefinitions, Serializable {
 
    /**
     * PDU type. Types are defined in 
     * {@link com.sun.jmx.snmp.SnmpDefinitions SnmpDefinitions}.
     * @serial
     */
    public int type=0 ;
  
    /**
     * Protocol version. Versions are defined in 
     * {@link com.sun.jmx.snmp.SnmpDefinitions SnmpDefinitions}.
     * @serial
     */
    public int version=0 ;
  
    /**
     * List of variables.
     * @serial
     */
    public SnmpVarBind[] varBindList ;


    /**
     * Request identifier.
     * Note that this field is not used by <CODE>SnmpPduTrap</CODE>.
     * @serial
     */
    public int requestId=0 ;

    /**
     * Source or destination address.
     * <P>For an incoming PDU it's the source.
     * <BR>For an outgoing PDU it's the destination.
     * @serial
     */
    public InetAddress address ;
  
    /**
     * Source or destination port.
     * <P>For an incoming PDU it's the source.
     * <BR>For an outgoing PDU it's the destination.
     * @serial
     */
    public int port=0 ;
    
    /**
     * Returns the <CODE>String</CODE> representation of a PDU type. 
     * For instance, if the PDU type is <CODE>SnmpDefinitions.pduGetRequestPdu</CODE>, 
     * the method will return "SnmpGet".
     * @param cmd The integer representation of the PDU type.
     * @return The <CODE>String</CODE> representation of the PDU type.
     */
    public static String pduTypeToString(int cmd) {
	switch (cmd) {
	case pduGetRequestPdu :
	    return "SnmpGet" ;
	case pduGetNextRequestPdu :
	    return "SnmpGetNext" ;
	case pduWalkRequest :
	    return "SnmpWalk(*)" ;
	case pduSetRequestPdu :
	    return "SnmpSet" ;
	case pduGetResponsePdu :
	    return "SnmpResponse" ;
	case pduV1TrapPdu :
	    return "SnmpV1Trap" ;
	case pduV2TrapPdu :
	    return "SnmpV2Trap" ;
	case pduGetBulkRequestPdu :
	    return "SnmpGetBulk" ;
	case pduInformRequestPdu :
	    return "SnmpInform" ;
	}
	return "Unknown Command = " + cmd ;
    }  
}