be.fedict.trust.service.snmp.mbean.SNMPService.java Source code

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Here is the source code for be.fedict.trust.service.snmp.mbean.SNMPService.java

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/*
 * eID Trust Service Project.
 * Copyright (C) 2009-2010 FedICT.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License version
 * 3.0 as published by the Free Software Foundation.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, see 
 * http://www.gnu.org/licenses/.
 */

package be.fedict.trust.service.snmp.mbean;

import java.io.File;
import java.io.IOException;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.snmp4j.agent.DuplicateRegistrationException;
import org.snmp4j.agent.mo.MOAccessImpl;
import org.snmp4j.smi.OID;
import org.snmp4j.smi.Variable;

public class SNMPService implements SNMPServiceMBean {

    private static final Log LOG = LogFactory.getLog(SNMPService.class);

    private String address;

    private Thread snmpThread;
    private SNMPAgent snmpAgent;

    private Map<String, Long> snmpValues;

    /**
     * {@inheritDoc}
     */
    public Long getValue(String oid) {

        initSNMPAgent();

        Long value = this.snmpValues.get(oid);
        if (null == value) {
            value = 0L;
            this.snmpValues.put(oid, value);
            try {
                addSNMPCounter(oid);
            } catch (DuplicateRegistrationException e) {
                LOG.warn("Counter with oid=" + oid + " already registered.");
            }
        }

        LOG.debug("getValue: oid=" + oid + " value=" + value);
        return value;
    }

    /**
     * {@inheritDoc}
     */
    public void setValue(String oid, Long value) {

        initSNMPAgent();

        if (null == this.snmpValues.get(oid)) {
            try {
                addSNMPCounter(oid);
            } catch (DuplicateRegistrationException e) {
                LOG.warn("Counter with oid=" + oid + " already registered.");
            }
        }
        this.snmpValues.put(oid, value);

        LOG.debug("setValue: oid=" + oid + " value=" + value);
    }

    /**
     * {@inheritDoc}
     */
    public void increment(String oid, Long increment) {

        initSNMPAgent();

        Long value = this.snmpValues.get(oid);
        if (null == value) {
            this.snmpValues.put(oid, increment);
            try {
                addSNMPCounter(oid);
            } catch (DuplicateRegistrationException e) {
                LOG.warn("Counter with oid=" + oid + " already registered.");
            }
        } else {
            this.snmpValues.put(oid, value + increment);
        }
        LOG.debug("increment: oid=" + oid + " value=" + snmpValues.get(oid));
    }

    /**
     * Initialized the {@link SNMPAgent} if not yet done so.
     */
    private synchronized void initSNMPAgent() {

        if (null == this.snmpAgent) {
            LOG.debug("Start SNMP agent @ address=" + this.address);
            try {
                this.snmpAgent = new SNMPAgent(this.address, new File("performance.snmp.agent.boot.counter.cfg"),
                        new File("performance.snmp.agent.cfg"));
            } catch (IOException e) {
                LOG.error("Failed to start SNMP agent: " + e.getMessage(), e);
                throw new RuntimeException(e);
            }
            this.snmpThread = new Thread(this.snmpAgent);
            this.snmpThread.start();

            this.snmpValues = Collections.synchronizedMap(new HashMap<String, Long>());
        }
    }

    /**
     * Register a new {@link Counter} for the specified oid in the
     * {@link SNMPAgent}.
     * 
     * @param oid
     * @throws DuplicateRegistrationException
     */
    private void addSNMPCounter(final String oid) throws DuplicateRegistrationException {

        this.snmpAgent.registerCounter(new Counter(new OID(oid), MOAccessImpl.ACCESS_READ_ONLY) {

            @Override
            protected Variable getCounterValue() {

                return new org.snmp4j.smi.Counter64(SNMPService.this.snmpValues.get(oid));
            }
        });
    }

    /**
     * {@inheritDoc}
     */
    public String getAddress() {

        return this.address;
    }

    /**
     * {@inheritDoc}
     */
    public void setAddress(String address) {

        this.address = address;
    }
}