snmpbean.java

snmp zip 包开发snmp协议

// NAME
//      $RCSfile: SNMPBean.java,v $
// DESCRIPTION
//      [given below in javadoc format]
// DELTA
//      $Revision: 1.12 $
// CREATED
//      $Date: 2006/01/26 12:38:30 $
// COPYRIGHT
//      Westhawk Ltd
// TO DO
//

/*
 * Copyright (C) 1998 - 2006 by Westhawk Ltd
 *
 * Permission to use, copy, modify, and distribute this software
 * for any purpose and without fee is hereby granted, provided
 * that the above copyright notices appear in all copies and that
 * both the copyright notice and this permission notice appear in
 * supporting documentation.
 * This software is provided "as is" without express or implied
 * warranty.
 * author <a href="mailto:[e-mail]">Tim Panton</a>
 */

package uk.co.westhawk.snmp.beans;

import uk.co.westhawk.snmp.stack.*;
import uk.co.westhawk.snmp.pdu.*;
import java.awt.*;
import java.util.*;
import java.text.*;
import java.lang.*;
import java.io.*;
import java.beans.*;

/**
 * <p>
 * This bean forms the base of the SNMP beans.
 * </p>
 *
 * <p>
 * <ul>
 * It provides the setting of the properties that are always needed when
 * sending a SNMP request:
 * <li>host, default is <em>localhost</em></li>
 * <li>port, default is <em>161</em></li>
 * <li>community name, default is <em>public</em></li>
 * <li>bindAddr, default is <em>null</em></li>
 * <li>socket type, default is <em>Standard</em></li>
 * </ul>
 * </p>
 *
 * <p>
 * The bean will only come into action when the method <em>action()</em> is
 * called. This should be done after the properties have been set.
 * </p>
 *
 * <p>
 * This bean also provide the methods for adding and removing property
 * change listeners and firing property change events.
 * </p>
 *
 * <p>
 * <ul>
 * Note: This bean will create a socket. This might result in a
 * SecurityException because of the Java security policy.
 * <li>
 * If you are an applet: you're only connect back to its source web server
 * </li>
 * <li>
 * If you are an application or servlet: java allows you to send it. The 
 * host might refuse your connection.
 * </li>
 * </ul>
 * </p>
 *
 * <p>
 * <ul>
 * The SNMP request will only succeed if:
 * <li>
 * java security policy allows the opening of the socket
 * </li>
 * <li>
 * the host/port combination is reachable from your location (you can
 * check that with the ping (command line) command. 
 * </li>
 * <li>
 * the combination of OID and community name is correct
 * </li>
 * </ul>
 * </p>
 *
 * @see SNMPRunBean
 * @see IsHostReachableBean
 * @see OneInterfaceBean
 * @see InterfaceIndexesBean
 *
 * @author <a href="mailto:[e-mail]">Birgit Arkesteijn</a>
 * @version $Revision: 1.12 $ $Date: 2006/01/26 12:38:30 $
 *
 */
public abstract class SNMPBean
{
    private static final String     version_id =
        "@(#)$Id: SNMPBean.java,v 1.12 2006/01/26 12:38:30 birgit Exp $ Copyright Westhawk Ltd";

    protected SnmpContext context = null;

    protected String host       = "localhost";
    protected String bindAddr   = null;
    protected int port          = 161;
    protected String community  = "public";
    protected String socketType = SnmpContextBasisFace.STANDARD_SOCKET;
    protected String message    = "";

    protected Vector propertyChangeListener = null;


/**
 * This method should send the SNMP request. All properties should be
 * set before this method is called.
 */
public abstract void action()
throws PduException, java.io.IOException;

/**
 * The default constructor.
 */
public SNMPBean() 
{
    propertyChangeListener = new Vector();
}

/**
 * The constructor that will set the host and the port no.
 *
 * @param h the hostname
 * @param p the port no
 * @see #setHost
 * @see #setPort
 */
public SNMPBean(String h, int p) 
{
    this(h, p, null, SnmpContextBasisFace.STANDARD_SOCKET);
}

/**
 * The constructor that will set the host, the port no and the local
 * bind address.
 *
 * @param h the hostname
 * @param p the port no
 * @param b the local bind address
 * @param t the socket type
 * @see #setHost
 * @see #setPort
 * @see #setBindAddress
 * @see #setSocketType
 *
 * @since 4_14
 */
public SNMPBean(String h, int p, String b, String t) 
{
    this();
    setHost(h);
    setPort(p);
    setBindAddress(b);
    setSocketType(t);
}

/**
 * Returns the host (name or ipadress) which is addressed. This is the
 * host where the SNMP server is running.
 * @return the name of the host
 * @see #setHost
 */
public String getHost()
{
    return host;
}

/**
 * Sets the host (name or ipadress) which will be asked for the SNMP request.
 * This is the host where the SNMP server is running.
 * The default is <em>localhost</em>.
 *
 * This bean will only start the request when action is called.
 *
 * @see #getHost
 */
public void setHost(String h) 
{
    if (h != null && h.length() > 0 && !host.equals(h))
    {
        host = h;
    }
}

/**
 * Returns the port no which is used. That is the no of the port on the
 * host where the SNMP server is running.
 * @see #setPort(int)
 * @see #setPort(String)
 */
public int getPort()
{
    return port;
}

/**
 * Sets the port no which is used. That should be the no of the port on the
 * host where the SNMP server is running.
 * The default is <em>161</em>.
 *
 * This bean will only start the request when action is called.
 *
 * @param p The number of the port
 * @see #getPort
 * @see #setPort(String)
 */
public void setPort(int p)
{
    if (p > 0 && port != p)
    {
        port = p;
    }
}

/**
 * Sets the port no which is used as a String.
 *
 * @param p The number of the port as a String
 * @see #getPort
 * @see #setPort(int)
 */
public void setPort(String p)
{
    int pNo;
    try
    {
        pNo = Integer.valueOf(p.trim()).intValue();
        setPort(pNo);
    }
    catch (NumberFormatException exp)
    {
    }
}

/**
 * Returns the community name that is used to send the SNMP request.
 * @see #setCommunityName
 */
public String getCommunityName()
{
    return community;
}

/**
 * Sets the community name that is used to send the SNMP request. The
 * default is <em>public</em>.
 * @see #getCommunityName
 */
public void setCommunityName(String c)
{
    if (c != null & !community.equals(c))
    {
        community = c;
        if (context != null)
        {
            context.setCommunity(community);
        }
    }
}

/**
 * Returns the local bind address. 
 * @return the name of the local bind address
 * @see #setBindAddress
 * @since 4_14
 */
public String getBindAddress()
{
    return bindAddr;
}

/**
 * Sets the local bind address.
 * The default is <em>null</em>.
 *
 * This bean will only start the request when action is called.
 *
 * @see #getBindAddress
 * @since 4_14
 */
public void setBindAddress(String b) 
{
    bindAddr = b;
}



/**
 * Returns the socket type.
 * @return the socket type.
 * @see #setSocketType
 * @since 4_14
 */
public String getSocketType()
{
    return socketType;
}

/**
 * Sets socket type.
 * The default is <em>null</em>.
 *
 * This bean will only start the request when action is called.
 *
 * @see #getSocketType
 * @see SnmpContextBasisFace#STANDARD_SOCKET
 * @since 4_14
 */
public void setSocketType(String t) 
{
    socketType = t;
}



/**
 * Indicates whether the host is reachable.
 * This method will try to make a new SnmpContext, if this works, it is
 * reachable.
 * If it does not work, the message will be set.
 *
 * @see SnmpContext
 */
protected boolean isHostPortReachable()
{
    boolean res = true;
    if (host != null
             &&
        host.length() > 0
             &&
        port > 0)
    {
        try
        {
            if (context != null)
            {
                context.destroy();
                context = null;
            }

            context = new SnmpContext(host, port, bindAddr, socketType);
            context.setCommunity(community);
            setMessage("Connection to host " + host 
                + " is made succesfully");
        }
        catch (IOException exc)
        {
            res = false;
            setMessage("IOException: " + exc.getMessage());
        }
        catch (RuntimeException exc)
        {
            res = false;
            setMessage("RuntimeException: " + exc.getMessage());
        }
    }
    else
    {
        res = false;
    }
    return res;
}

/**
 * Returns the message (if any). The message is used to give the user
 * feedback if anything is happened with the request or the connection.
 *
 * @return the message
 */
public String getMessage()
{
    return message;
}

/**
 * Returns the message (if any). The message is used to give the user
 * feedback if anything is happened (usually when something went wrong)
 * with the connection.
 *
 * @param st the message string
 * @see #getMessage()
 */
protected void setMessage(String st)
{
    message = st;
}


/**
 * Add a property change listener.
 * @see #removePropertyChangeListener
 */
public synchronized void addPropertyChangeListener(PropertyChangeListener l)
{
    propertyChangeListener.addElement(l);
}

/**
 * Remove a property change listener.
 * @see #addPropertyChangeListener
 */
public synchronized void removePropertyChangeListener(PropertyChangeListener l)
{
    propertyChangeListener.removeElement(l);
}
 
/**
 * Fire the property event.
 *
 * @see #removePropertyChangeListener
 * @see #addPropertyChangeListener
 * @see PropertyChangeEvent
 * @see PropertyChangeListener
 */
protected void firePropertyChange(String property, Object old_v, Object new_v)
{
    Vector listeners;
    synchronized(this)
    {
        listeners = (Vector) propertyChangeListener.clone();
    }

    PropertyChangeEvent event = new PropertyChangeEvent(this, 
          property, old_v, new_v);
 
    int sz = listeners.size();
    for (int i=0; i<sz; i++)
    {
        PropertyChangeListener l = (PropertyChangeListener) 
                listeners.elementAt(i);
        l.propertyChange(event);
    }
}

}