AsyncBasicDetectorMinaImpl.java

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 * Copyright (C) 2008-2011 The OpenNMS Group, Inc.
 * OpenNMS(R) is Copyright (C) 1999-2011 The OpenNMS Group, Inc.
 *
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 *
 * OpenNMS(R) is free software: you can redistribute it and/or modify
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package org.opennms.netmgt.provision.support;

import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;

import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;

import org.apache.mina.core.filterchain.IoFilterAdapter;
import org.apache.mina.core.future.ConnectFuture;
import org.apache.mina.core.future.IoFutureListener;
import org.apache.mina.core.service.IoHandler;
import org.apache.mina.core.session.IdleStatus;
import org.apache.mina.core.session.IoSession;
import org.apache.mina.core.session.IoSessionInitializer;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.mina.filter.codec.textline.TextLineCodecFactory;
import org.apache.mina.filter.logging.LoggingFilter;
import org.apache.mina.filter.ssl.SslFilter;
import org.opennms.core.utils.InetAddressUtils;
import org.opennms.core.utils.LogUtils;
import org.opennms.netmgt.provision.DetectFuture;
import org.opennms.netmgt.provision.support.trustmanager.RelaxedX509TrustManager;

/**
 * <p>AsyncBasicDetectorMinaImpl class.</p>
 *
 * @author Donald Desloge
 * @version $Id: $
 */
public abstract class AsyncBasicDetectorMinaImpl<Request, Response> extends AsyncBasicDetector<Request, Response> {
    
    private BaseDetectorHandler<Request, Response> m_detectorHandler = new BaseDetectorHandler<Request, Response>();
    private IoFilterAdapter m_filterLogging = null;
    private ProtocolCodecFilter m_protocolCodecFilter = new ProtocolCodecFilter(new TextLineCodecFactory(CHARSET_UTF8));
    
    private final ConnectionFactory m_connectionFactory;
    
    /**
     * <p>Constructor for AsyncBasicDetector.</p>
     *
     * @param serviceName a {@link java.lang.String} object.
     * @param port a int.
     * @param <Request> a Request object.
     * @param <Response> a Response object.
     */
    public AsyncBasicDetectorMinaImpl(final String serviceName, final int port) {
        super(serviceName, port);
        m_connectionFactory = ConnectionFactory.getFactory(getTimeout());
    }
    
    /**
     * <p>Constructor for AsyncBasicDetector.</p>
     *
     * @param serviceName a {@link java.lang.String} object.
     * @param port a int.
     * @param timeout a int.
     * @param retries a int.
     */
    public AsyncBasicDetectorMinaImpl(final String serviceName, final int port, final int timeout, final int retries){
        super(serviceName, port, timeout, retries);
        m_connectionFactory = ConnectionFactory.getFactory(getTimeout());
    }
    
    /**
     * <p>dispose</p>
     */
    @Override
    public void dispose(){
        LogUtils.debugf(this, "calling dispose on detector %s", getServiceName());
        ConnectionFactory.dispose(m_connectionFactory);
    }
    
    /** {@inheritDoc} */
    @Override
    public final DetectFuture isServiceDetected(final InetAddress address) {

        final DetectFutureMinaImpl detectFuture = new DetectFutureMinaImpl(this);

        try {
            // Set this up here because it can throw an Exception, which we want
            // to throw now, not in initializeSession
            final SSLContext c = createClientSSLContext();

            // Create an IoSessionInitializer that will configure this individual
            // session. Previously, all this was done on a new Connector each time
            // but that was leaking file handles all over the place. This way gives
            // us per-connection settings without the overhead of creating new
            // Connectors each time
            IoSessionInitializer<ConnectFuture> init = new IoSessionInitializer<ConnectFuture>() {

                public void initializeSession(IoSession session, ConnectFuture future) {
                    // Add filters to the session
                    if(isUseSSLFilter()) {
                        final SslFilter filter = new SslFilter(c);
                        filter.setUseClientMode(true);
                        session.getFilterChain().addFirst("SSL", filter);
                    }
                    session.getFilterChain().addLast( "logger", getLoggingFilter() != null ? getLoggingFilter() : new LoggingFilter() );
                    session.getFilterChain().addLast( "codec", getProtocolCodecFilter());
                    session.getConfig().setIdleTime(IdleStatus.READER_IDLE, getIdleTime());
                }
            };

            // Start communication
            final InetSocketAddress socketAddress = new InetSocketAddress(address, getPort());
            // Get an ephemeral port on the localhost interface
            final InetSocketAddress localAddress = new InetSocketAddress(InetAddressUtils.getLocalHostAddress(), 0);
            final ConnectFuture cf = m_connectionFactory.connect(socketAddress, localAddress, init, createDetectorHandler(detectFuture));
            cf.addListener(retryAttemptListener(detectFuture, socketAddress, init, getRetries()));
        } catch (KeyManagementException e) {
            detectFuture.setException(e);
        } catch (NoSuchAlgorithmException e) {
            detectFuture.setException(e);
        } catch (Throwable e) {
            detectFuture.setException(e);
        }

        return detectFuture;
    }

    /**
     * @return
     * @throws NoSuchAlgorithmException 
     * @throws KeyManagementException 
     */
    private static final SSLContext createClientSSLContext() throws NoSuchAlgorithmException, KeyManagementException {
        final TrustManager[] tm = { new RelaxedX509TrustManager() };
        final SSLContext sslContext = SSLContext.getInstance("SSL");
        sslContext.init(null, tm, new java.security.SecureRandom());
        return sslContext;
    }

    /**
     * Handles the retry attempts. Listens to see when the ConnectFuture is finished and checks if there was 
     * an exception thrown. If so, it then attempts a retry if there are more retries.
     * 
     * @param connector
     * @param detectFuture
     * @param address
     * @param retryAttempt
     * @return IoFutureListener<ConnectFuture>
     */
    private final IoFutureListener<ConnectFuture> retryAttemptListener(final DetectFutureMinaImpl detectFuture, final InetSocketAddress address, final IoSessionInitializer<ConnectFuture> init, final int retryAttempt) {
        return new IoFutureListener<ConnectFuture>() {

            @Override
            public void operationComplete(ConnectFuture future) {
                final Throwable cause = future.getException();
               
                if (cause instanceof IOException) {
                    if(retryAttempt == 0) {
                        LogUtils.infof(this, "Service %s detected false",getServiceName());
                        detectFuture.setServiceDetected(false);
                    }else {
                        LogUtils.infof(this, "Connection exception occurred %s for service %s, retrying attempt %d", cause, getServiceName(), retryAttempt);
                        // Get an ephemeral port on the localhost interface
                        final InetSocketAddress localAddress = new InetSocketAddress(InetAddressUtils.getLocalHostAddress(), 0);
                        future = m_connectionFactory.reConnect(address, localAddress, init, createDetectorHandler(detectFuture));
                        future.addListener(retryAttemptListener(detectFuture, address, init, retryAttempt - 1));
                    }
                }else if(cause instanceof Throwable) {
                    LogUtils.infof(this, cause, "Threw a Throwable and detection is false for service %s", getServiceName());
                    detectFuture.setServiceDetected(false);
                }
            }
            
        };
    }

    /**
     * <p>setDetectorHandler</p>
     *
     * @param detectorHandler a {@link org.opennms.netmgt.provision.support.BaseDetectorHandler} object.
     */
    protected final void setDetectorHandler(final BaseDetectorHandler<Request, Response> detectorHandler) {
        m_detectorHandler = detectorHandler;
    }
    
    /**
     * <p>createDetectorHandler</p>
     *
     * @param future a {@link org.opennms.netmgt.provision.DetectFuture} object.
     * @return a {@link org.apache.mina.core.service.IoHandler} object.
     */
    protected final IoHandler createDetectorHandler(final DetectFutureMinaImpl future) {
        m_detectorHandler.setConversation(getConversation());
        m_detectorHandler.setFuture(future);
        return m_detectorHandler;
    }

    /**
     * <p>setLoggingFilter</p>
     *
     * @param filterLogging a {@link org.apache.mina.core.filterchain.IoFilterAdapter} object.
     */
    protected final void setLoggingFilter(final IoFilterAdapter filterLogging) {
        m_filterLogging = filterLogging;
    }

    /**
     * <p>getLoggingFilter</p>
     *
     * @return a {@link org.apache.mina.core.filterchain.IoFilterAdapter} object.
     */
    protected final IoFilterAdapter getLoggingFilter() {
        return m_filterLogging;
    }

    /**
     * <p>setProtocolCodecFilter</p>
     *
     * @param protocolCodecFilter a {@link org.apache.mina.filter.codec.ProtocolCodecFilter} object.
     */
    protected final void setProtocolCodecFilter(final ProtocolCodecFilter protocolCodecFilter) {
        m_protocolCodecFilter = protocolCodecFilter;
    }

    /**
     * <p>getProtocolCodecFilter</p>
     *
     * @return a {@link org.apache.mina.filter.codec.ProtocolCodecFilter} object.
     */
    protected final ProtocolCodecFilter getProtocolCodecFilter() {
        return m_protocolCodecFilter;
    }

    /**
     * <p>getDetectorHandler</p>
     *
     * @return a {@link org.apache.mina.core.service.IoHandler} object.
     */
    protected final IoHandler getDetectorHandler() {
        return m_detectorHandler;
    }
}