org.sglj.service.rmi.server.NotificationServiceStub.java Source code

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Here is the source code for org.sglj.service.rmi.server.NotificationServiceStub.java

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/*
 * NotificationServiceStub.java
 * 
 * Copyright (C) 2010 Leo Osvald <leo.osvald@gmail.com>
 * 
 * This file is part of SGLJ.
 * 
 * SGLJ is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * SGLJ 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 library.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.sglj.service.rmi.server;

import java.lang.reflect.Method;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import org.apache.commons.lang.reflect.MethodUtils;
import org.sglj.service.rmi.NotificationService;
import org.sglj.service.rmi.RemoteCallRequest;
import org.sglj.service.rmi.ServiceReflectionCallException;
import org.sglj.service.rmi.annotations.RemoteMethod;

/**
 * Stub implementation which delegates the call of a method to the
 * associated {@link NotificationSender}.<br> 
 * All implementing classes should just tag  method with
 * the {@link RemoteMethod} annotation and call the
 * {@link #callNotificationMethod(Object[], String, Object...)} method
 * which delegates the call to the sender.  
 *  
 * @author Leo Osvald
 *
 * @param <T> type of the info about recipients
 */
public abstract class NotificationServiceStub<T> implements NotificationService {

    private final Set<Method> remoteMethods;

    private final NotificationSender<T> sender;

    public NotificationServiceStub(NotificationSender<T> notificationSender) {
        this.sender = notificationSender;

        Method[] methods = this.getClass().getDeclaredMethods();
        Set<Method> set = new HashSet<Method>();
        for (Method m : methods) {
            if (!m.isAccessible()) {
                try {
                    m.setAccessible(true);
                } catch (SecurityException ignorable) {
                }
            }
            RemoteMethod annot = m.getAnnotation(RemoteMethod.class);
            if (annot != null && annot.value() == RemoteMethod.RemoteMethodSide.CALLER
                    && m.getReturnType() == void.class) {
                set.add(m);
            }
        }
        this.remoteMethods = Collections.unmodifiableSet(set);
    }

    protected void callNotificationMethod(T[] recipients, String methodName, Object... args)
            throws ServiceReflectionCallException {

        Class<?>[] paramTypes = new Class<?>[args == null ? 0 : args.length];
        if (args != null) {
            for (int i = 0; i < paramTypes.length; ++i) {
                paramTypes[i] = args[i].getClass();
            }
        }

        Method method;
        try {
            method = MethodUtils.getMatchingAccessibleMethod(this.getClass(), methodName, paramTypes);
        } catch (SecurityException e) {
            e.printStackTrace();
            throw new ServiceReflectionCallException(e);
        }
        if (!this.remoteMethods.contains(method)) {
            throw new ServiceReflectionCallException("No such method");
        }

        this.sender.sendNotification(recipients, new RemoteCallRequest(getId(), methodName, args));
    }

    /**
     * A convenient method for building the array of the recipients.
     * 
     * @param <T> type of the recipient info
     * @param recipients recipient info
     * @return the array of recipient info
     */
    protected static <T> T[] buildRecipientList(T... recipients) {
        return recipients;
    }

}