scr/examples/service/src/main/java/org/apache/karaf/scr/examples/service/component/GreeterComponent.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.karaf.scr.examples.service.component;

import aQute.bnd.annotation.component.Activate;
import aQute.bnd.annotation.component.Component;
import aQute.bnd.annotation.component.Deactivate;
import aQute.bnd.annotation.component.Reference;
import org.apache.karaf.scr.examples.service.GreeterService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Component(name = GreeterComponent.COMPONENT_NAME)
public class GreeterComponent {

    public static final String COMPONENT_NAME = "GreeterComponent";
    public static final String COMPONENT_LABEL = "Greeter Service Component";

    private static final Logger LOG = LoggerFactory.getLogger(GreeterComponent.class);

    private GreeterService greeterService;

    /**
     * Called when all of the SCR Components required dependencies have been satisfied.
     */
    @Activate
    public void activate() {
        LOG.info("Activating the {}", COMPONENT_LABEL);
        greeterService.printGreetings();
    }

    /**
     * Called when any of the SCR Components required dependencies become unsatisfied.
     */
    @Deactivate
    public void deactivate() {
        LOG.info("Deactivating the {}", COMPONENT_LABEL);
    }

    @Reference
    public void setGreeterService(final GreeterService greeterService) {
        this.greeterService = greeterService;
    }

    public void unsetGreeterService(final GreeterService greeterService) {
        this.greeterService = null;
    }

}