asyncmdb.java

CRM源码This file describes some issues that should be implemented in future and how it should be imple

/*
 * Copyright 2006-2007 Queplix Corp.
 *
 * Licensed under the Queplix Public License, Version 1.1.1 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.queplix.com/solutions/commercial-open-source/queplix-public-license/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package com.queplix.core.modules.eql.ejb;

import com.queplix.core.integrator.security.LogonSession;
import com.queplix.core.integrator.security.AccessRightsManager;
import com.queplix.core.modules.services.utils.log.impl.MailLogPublisher;
import com.queplix.core.utils.async.ASyncObject;
import com.queplix.core.utils.async.ASyncRequest;
import com.queplix.core.utils.log.AbstractLogger;
import com.queplix.core.utils.log.Log;

import javax.ejb.EJBException;
import javax.ejb.MessageDrivenBean;
import javax.ejb.MessageDrivenContext;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageListener;
import javax.jms.ObjectMessage;
import javax.transaction.UserTransaction;
import java.util.HashMap;

/**
 * Message Driven Bean for working with asynchronous requests.
 * @author [BAA] Alexander Balandin
 * @author [ONZ] Oleg N. Zhovtanyuk
 * @author [ALB] Baranov Andrey
 */

public class AsyncMDB
    implements MessageDrivenBean, MessageListener {

    // ================================================================== Constants

    public static final String OBJECT_PARAM = "object";
    public static final String REQUEST_PARAM = "request";

    // ================================================================== Fields

    /** Runtime MDB context reference. */
    protected MessageDrivenContext ctx = null;

    /** Logger. */
    private AbstractLogger logger = null;

    // ============================================================= API methods

    /**
     * Sets MDB context.
     * @param ctx MDB context
     */
    public void setMessageDrivenContext( MessageDrivenContext ctx ) {
        this.ctx = ctx;
    }

    /** Creates MDB. */
    public void ejbCreate() {
        logger = Log.getLog( getClass() );
        logger.INFO( "[+] AsyncMDB [" + hashCode() + "] created" );
    }

    /** Remove MDB. */
    public void ejbRemove() {
        logger.INFO( "[-] AsyncMDB [" + hashCode() + "] removed" );
    }

    /**
     * Gets a message.
     * @param msg message
     */
    public void onMessage( Message msg ) {

        boolean error = false;
        UserTransaction userTran = ctx.getUserTransaction();

        // Go!
        try {

            // Message type checking.
            if( ! ( msg instanceof ObjectMessage ) ) {
                logger.ERROR( "AsyncMDB [" + hashCode() + "] got unknown message: " + msg );
                return;
            }

            if( logger.getLogger().isDebugEnabled() ) {
                logger.DEBUG( "AsyncMDB [" + hashCode() + "] got message: " + msg );
            }

            //
            // Retriving HashMap with message data.
            //
            Object o = ( ( ObjectMessage ) msg ).getObject();
            if( o == null || ! ( o instanceof HashMap ) ) {
                logger.ERROR( "Can't get data hash from message: " + msg );
                return;
            }
            HashMap map = ( HashMap ) o;

            //
            // Getting the ASyncObject object.
            //
            ASyncObject obj;
            o = map.get( OBJECT_PARAM );
            if( o != null ) {
                logger.DEBUG( "Async object:" );
                logger.DEBUG( "		class: " + o.getClass().getName() );
                logger.DEBUG( "		object: " + o );
                obj = ( ASyncObject ) o;
            } else {
                logger.ERROR( "Can't get 'OBJECT_PARAM' from HashMap: " + map );
                return;
            }

            //
            // Getting the request object.
            //
            ASyncRequest request = null;
            o = map.get( REQUEST_PARAM );
            if( o != null ) {
                logger.DEBUG( "Request object class name: " + o.getClass().getName() );
                request = ( ASyncRequest ) o;
            }

            // Begin the transaction.
            userTran.begin();

            //
            // Processing request.
            //
            obj.process( request );

            // Commit.
            userTran.commit();

        } catch( JMSException ex ) {

            //
            // Caught JMS exception.
            //
            error = true;
            try {
                userTran.rollback();
            } catch( Throwable t ) {
                traceError(t);
            }

            // Tracing error.
            traceError( ex );

        } catch( Exception ex ) {

            //
            // Caught unknown exception.
            //
            error = true;
            try {
                userTran.rollback();
            } catch( Throwable t ) {
                traceError(t);
            }

            // Tracing error.
            traceError( ex );
        }

        if( logger.getLogger().isDebugEnabled() ) {
            if( error ) {
                logger.DEBUG( "AsyncMDB [" + hashCode() + "] finished with error" );
            } else {
                logger.DEBUG( "AsyncMDB [" + hashCode() + "] finished successfully" );
            }
        }

    } // onMessage()

    // ============================================================= Private methods

    //
    // Trace error.
    // Send error message from admin.
    //
    private void traceError( Throwable t ) {

        // Tracing error.
        logger.ERROR( "=================================" );
        logger.ERROR( "Caught exception in Async MDB: " + t );
        logger.ERROR( "Stack:" );
        logger.ERROR( t );
        logger.ERROR( "=================================" );

        try {
            // Get Admin logon session.
            LogonSession ls = AccessRightsManager.getSystemLogonSession();

            // Sending mail.
            new MailLogPublisher( ls, getClass() ).ERROR( getCauseException( t ) );

        } catch( Throwable t2 ) {
            t2.printStackTrace();
        }
    }

    //
    // Try to find cause exception.
    //
    private Throwable getCauseException( Throwable t ) {

        if( t == null ) {
            return null;
        }

        // if EJB exception - takes cause exception
        if( ( t instanceof EJBException ) && ( ( EJBException ) t ).getCausedByException() != null ) {
            return getCauseException( ( ( EJBException ) t ).getCausedByException() );
        } else {
            return t;
        }
    }
}