/*
* 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.managed.service.impl;
import org.apache.karaf.scr.examples.managed.service.ManagedGreeterService;
import org.osgi.service.component.annotations.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
/**
* An implementation of the ManagedGreeterService interface. Component configuration includes setting
* the name attribute and setting the configuration policy to required. The default is optional and when the
* component attempts to activate it will throw a RuntimeException.
*/
@Component(name = ManagedGreeterServiceImpl.COMPONENT_NAME, configurationPolicy = ConfigurationPolicy.REQUIRE)
public class ManagedGreeterServiceImpl implements ManagedGreeterService {
public static final String COMPONENT_NAME = "ManagedGreeterService";
public static final String COMPONENT_LABEL = "Managed Greeter Service";
private static final Logger LOG = LoggerFactory.getLogger(ManagedGreeterServiceImpl.class);
private ExecutorService executor = Executors.newCachedThreadPool();
private Worker worker = new Worker();
private ReadWriteLock lock = new ReentrantReadWriteLock();
/**
* Called when all of the SCR Components required dependencies have been satisfied.
*
* @param properties The activation properties.
*/
@Activate
public void activate(final Map<String, ?> properties) {
LOG.info("Activating the {}", COMPONENT_LABEL);
// just because our component has a policy of required doesn't help to ensure our properties are set
// first check that salutation is set
if (properties.containsKey("salutation")) {
try {
lock.writeLock().lock();
worker.setSalutation((String) properties.get("salutation"));
} finally {
lock.writeLock().unlock();
}
} else {
throw new IllegalArgumentException("The salutation property may not be null or empty: " + properties.get("salutation"));
}
// now verify that name is set
if (properties.containsKey("name")) {
try {
lock.writeLock().lock();
worker.setName((String) properties.get("name"));
} finally {
lock.writeLock().unlock();
}
} else {
throw new IllegalArgumentException("The name property may not be null or empty: " + properties.get("name"));
}
}
/**
* Called when any of the SCR Components required dependencies become unsatisfied.
*/
@Deactivate
public void deactivate() {
LOG.info("Deactivating the {}", COMPONENT_LABEL);
}
/**
* Called when the configuration associated with this component has been updated.
*
* @param properties The updated configuration.
*/
@Modified
public void modified(final Map<String, ?> properties) {
LOG.info("Modifying the {}", COMPONENT_LABEL);
// this time we really only need to make sure if it changed it isn't empty
if (properties.containsKey("salutation") && !properties.get("salutation").equals("")) {
try {
lock.writeLock().lock();
worker.setSalutation((String) properties.get("salutation"));
} finally {
lock.writeLock().unlock();
}
}
// same for name
if (properties.containsKey("name") && !properties.get("name").equals("")) {
try {
lock.writeLock().lock();
worker.setName((String) properties.get("name"));
} finally {
lock.writeLock().unlock();
}
}
}
public void startGreeter() {
try {
lock.writeLock().lock();
executor.execute(worker);
} finally {
lock.writeLock().unlock();
}
}
public void stopGreeter() {
try {
lock.writeLock().lock();
if (!executor.isTerminated()) {
executor.shutdownNow();
}
} finally {
lock.writeLock().unlock();
}
}
/**
* Thread worker that continuously prints a message.
*/
private class Worker implements Runnable {
private String name;
private String salutation;
public void run() {
boolean running = true;
int messageCount = 0;
while (running) {
try {
LOG.info("Message {}: {} {}", messageCount, salutation, name);
Thread.sleep(1000);
} catch (InterruptedException e) {
running = false;
LOG.info("Thread shutting down");
}
}
}
public void setName(String name) {
this.name = name;
}
public void setSalutation(String salutation) {
this.salutation = salutation;
}
}
}