net.sf.eBusx.monitor.MonitorUpdate Maven / Gradle / Ivy

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//
// Copyright 2012, 2013, 2016, 2019, 2020 Charles W. Rapp
//
// Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
//
// 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 net.sf.eBusx.monitor;

import java.io.Serializable;
import net.sf.eBus.messages.ENotificationMessage;
import net.sf.eBus.util.Validator;

/**
 * Reports the {@link Monitor#register(Monitorable) registration}
 * or {@link Monitor#deregister(Monitorable) deregistration} or
 * a {@link Monitorable} instance. The {@link #instance} field
 * contains the monitored object unique identifier and
 * {@link #updateFlag} is {@code true} if the object registered
 * and {@code false} if the object deregistered.
 * 
 * In order to receive this notification message, subscribe to:
 * {@code net.sf.eBusx.monitor.MonitorUpdate}:{@link Monitor#MONITOR_UPDATE_SUBJECT}.
 *
 * @see ApplicationInfo
 * @see Monitor
 *
 * @author Charles Rapp
 */

public final class MonitorUpdate
    extends ENotificationMessage
    implements Serializable
{

//---------------------------------------------------------------
// Member data.
//

    //-----------------------------------------------------------
    // Constants.
    //

    /**
     * Serialization version identifier.
     */
    private static final long serialVersionUID = 0x050200L;

    //-----------------------------------------------------------
    // Locals.
    //

    /**
     * This monitored object was either added or removed.
     */
    public final MonitorId instance;

    /**
     * {@code true} if added and {@code false} if removed.
     */
    public final boolean updateFlag;

//---------------------------------------------------------------
// Member methods.
//

    //-----------------------------------------------------------
    // Constructors.
    //

    private MonitorUpdate(final Builder builder)
    {
        super (builder);

        this.instance = builder.mInstance;
        this.updateFlag = builder.mUpdateFlag;
    } // end of MonitorUpdate(Builder)

    //
    // end of Constructors.
    //-----------------------------------------------------------

    //-----------------------------------------------------------
    // Object Method Overrides.
    //

    @Override
    public String toString()
    {
        final StringBuilder retval = new StringBuilder();

        retval.append(super.toString())
              .append("\n               instance: ")
              .append(instance)
              .append("\n                 update: ")
              .append(updateFlag);

        return (retval.toString());
    } // end of toString()

    //
    // end of Object Method Overrides.
    //-----------------------------------------------------------

    public static Builder builder()
    {
        return (new Builder());
    } // end of builder()

//---------------------------------------------------------------
// Inner classes.
//

    public static final class Builder
        extends ENotificationMessage.Builder
    {
    //-----------------------------------------------------------
    // Member data.
    //

        //-------------------------------------------------------
        // Locals.
        //

        private MonitorId mInstance;
        private boolean mUpdateFlag;

    //-----------------------------------------------------------
    // Member methods.
    //

        //-------------------------------------------------------
        // Constructors.
        //

        private Builder()
        {
            super (MonitorUpdate.class);

            this.subject(Monitor.MONITOR_UPDATE_SUBJECT);
        } // end of Builder()

        //
        // end of Constructors.
        //-------------------------------------------------------

        //-------------------------------------------------------
        // Builder Method Overrides.
        //

        @Override
        protected MonitorUpdate buildImpl()
        {
            return (new MonitorUpdate(this));
        } // end of buildImpl()

        @Override
        protected Validator validate(final Validator problems)
        {
            return (super.validate(problems)
                         .requireNotNull(mInstance, "instance"));
        } // end of validate(Validator)

        //
        // end of Builder Method Overrides.
        //-------------------------------------------------------

        //-------------------------------------------------------
        // Set Methods.
        //

        public Builder instance(final MonitorId id)
        {
            if (id == null)
            {
                throw (new NullPointerException("id is null"));
            }

            mInstance = id;

            return (this);
        } // end of instance(MonitorId)

        public Builder updateFlag(final boolean flag)
        {
            mUpdateFlag = flag;

            return (this);
        } // end of updateFlag(boolean)

        //
        // end of Set Methods.
        //-------------------------------------------------------
    } // end of class Builder
} // end of class MonitorUpdate