2 * Copyright 2007 the original author or authors.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
16 package org.wamblee.system;
18 import java.util.ArrayList;
19 import java.util.Arrays;
20 import java.util.HashSet;
21 import java.util.List;
24 import org.apache.commons.logging.Log;
25 import org.apache.commons.logging.LogFactory;
28 * Abstract subsystem class making it easy to implement new subsystems.
30 public abstract class AbstractComponent implements Component {
32 private static final Log LOG = LogFactory.getLog(AbstractComponent.class);
34 private Status _status;
35 private String _context;
37 private List<ProvidedInterface> _provided;
38 private List<RequiredInterface> _required;
39 private Set<ProvidedInterface> _running;
42 * Constructs the subsystem.
51 protected AbstractComponent(String aName, ProvidedInterface[] aProvided,
52 RequiredInterface[] aRequired) {
53 _status = Status.NOT_STARTED;
56 _provided = new ArrayList<ProvidedInterface>();
57 _provided.addAll(Arrays.asList(aProvided));
58 _required = new ArrayList<RequiredInterface>();
59 _required.addAll(Arrays.asList(aRequired));
60 _running = new HashSet<ProvidedInterface>();
64 public Status getStatus() {
69 public final String getName() {
74 public String getQualifiedName() {
75 if ( _context == null ) {
78 return _context + "." + getName();
82 public final ProvidedInterface[] getProvidedServices() {
83 return _provided.toArray(new ProvidedInterface[0]);
87 public final RequiredInterface[] getRequiredServices() {
88 return _required.toArray(new RequiredInterface[0]);
92 public final void start(String aContext) {
93 LOG.info("Initializing '" + aContext + "." + _name + "'");
95 doStart(aContext + "." + getName());
96 _status = Status.RUNNING;
97 if ( _running.size() != _provided.size()) {
98 List<ProvidedInterface> remaining =
99 new ArrayList<ProvidedInterface>(_provided);
100 remaining.removeAll(_running);
101 throw new SystemAssemblyException(aContext + "." + getName() + ": not all services were started, missing " + remaining);
106 * Must be implemented for initializing the subsystem. The implementation
107 * must call {@link #addService(Service)} for each service that is started.
109 protected abstract void doStart(String aContext);
112 * Implementations must call this method to indicate that a new service has
118 protected final void addService(String aContext,
119 ProvidedInterface aDescriptor, Object aService) {
120 LOG.info(aContext + ": service '" + aService + "' started.");
121 _running.add(aDescriptor);
122 aDescriptor.publish(aService);
126 public ProvidedInterface[] getRunningServices() {
127 return _running.toArray(new ProvidedInterface[0]);
133 _status = Status.STOPPED;
136 protected abstract void doStop();
139 public String toString() {