cacheobjectmanager.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.utils.cache;

import com.queplix.core.error.GenericSystemException;

import javax.naming.InitialContext;
import javax.rmi.PortableRemoteObject;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

/**
 * <p>Cache Remote/Local objects</p>
 * @author Baranov Andrey [ALB]
 * @version $Revision: 1.2 $ $Date: 2006/04/03 06:47:56 $
 */

public class CacheObjectManager
    implements Serializable {

    // Contains the table of home objects.
    private transient Map __localHomeObjectTable;
    private transient Map __remoteHomeObjectTable;

    /**
     * Gets remote EJB home interface.
     * @param jndiName JNDI name
     * @param homeClass home class
     * @return remote home object
     */
    public Object getRemoteHome( String jndiName, Class homeClass ) {

        Map remoteHomeObjectTable = getRemoteHomeObjectTable();
        String key = homeClass.getName();
        Object home = remoteHomeObjectTable.get( key );
        try {
            if( home == null ) {
                synchronized( this ) {
                    if( ( home = remoteHomeObjectTable.get( key ) ) == null ) {
                        Object o = new InitialContext().lookup( jndiName );
                        home = PortableRemoteObject.narrow( o, homeClass );
                        remoteHomeObjectTable.put( key, home );
                    }
                }
            }
        } catch( Throwable t ) {
            t.printStackTrace();
            throw new GenericSystemException( "Can't get remote home object by the name '" +
                                              jndiName + "': " + t.getMessage(), t );
        }

        return home;
    }

    /**
     * Gets EJB reference.
     * @param jndiName JNDI name
     * @param homeClass home class
     * @return remote object
     */
    public Object getRemoteObject( String jndiName, Class homeClass ) {

        Object remote = null;
        String key = homeClass.getName();
        Object home = getRemoteHome( jndiName, homeClass );

        try {
            Method createMethod = homeClass.getMethod( "create", new Class[0] );
            remote = createMethod.invoke( home, (Object[]) null );

        } catch( Throwable t ) {
            t.printStackTrace();
            throw new GenericSystemException( "Can't get remote object by the name '" +
                                              jndiName + "': " + t.getMessage(), t );
        }
        return remote;
    }

    /**
     * Gets EJB local home object.
     * @param jndiName JNDI name
     * @param homeClass home class
     * @return local home object
     */
    public Object getLocalHome( String jndiName, Class homeClass ) {

        Map localHomeObjectTable = getLocalHomeObjectTable();

        String key = homeClass.getName();
        Object home = localHomeObjectTable.get( key );

        try {
            if( home == null ) {
                synchronized( this ) {
                    if( ( home = localHomeObjectTable.get( key ) ) == null ) {
                        home = new InitialContext().lookup( jndiName );
                        localHomeObjectTable.put( key, home );
                    }
                }
            }

        } catch( Throwable t ) {
            t.printStackTrace();
            throw new GenericSystemException( "Can`t get local home object by the name '" +
                                              jndiName + "': " + t.getMessage(), t );
        }
        return home;
    }

    /**
     * Gets EJB local reference.
     * @param jndiName JNDI name
     * @param homeClass home class
     * @return local object
     */
    public Object getLocalObject( String jndiName, Class homeClass ) {

        Object local = null;
        String key = homeClass.getName();
        Object home = getLocalHome( jndiName, homeClass );

        try {
            Method createMethod = homeClass.getMethod( "create", new Class[0] );
            local = createMethod.invoke( home, (Object[]) null );

        } catch( Throwable t ) {
            t.printStackTrace();
            throw new GenericSystemException( "Can`t get local object by the name '" +
                                              jndiName + "': " + t.getMessage(), t );
        }
        return local;
    }

    // ----------------------------------------------------- private methods

    private synchronized Map getLocalHomeObjectTable() {
        if( __localHomeObjectTable == null ) {
            __localHomeObjectTable = Collections.synchronizedMap( new HashMap() );
        }
        return __localHomeObjectTable;
    }

    private synchronized Map getRemoteHomeObjectTable() {
        if( __remoteHomeObjectTable == null ) {
            __remoteHomeObjectTable = Collections.synchronizedMap( new HashMap() );
        }
        return __remoteHomeObjectTable;
    }
}