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.core;
19 * A component represents a part of a system that requires a
20 * number of interfaces and provides a number of interfaces.
22 * The component interface provides the meta-data for a component.
23 * After calling {@link #start(Scope)}, an actual runtime representation of the
24 * component can be created which is independent of this component.
25 * As a special case, the runtime representation may be identical to the
26 * component instance but in general it is not. This allows a component to be
27 * used as a factory for creating objects.
30 * @author Erik Brakkee
32 public interface Component<Type> {
35 * Gets the name of the subsystem.
36 * @return Subsystem name.
41 * Prepends the context with a super context.
43 void addContext(String aContext);
46 * Gets the fully qualified name of the component which includes
47 * the context of the component.
48 * This method can only be used after the component has started.
49 * @return Qualified name.
51 String getQualifiedName();
54 * Gets a description of the provided interfaces.
55 * @return Provided interfaces.
57 ProvidedInterface[] getProvidedInterfaces();
60 * Gets a description of the required interfaces.
61 * @return Required interfaces.
63 RequiredInterface[] getRequiredInterfaces();
67 * Initialises the subsystem by starting all the services that
68 * it described as provided.
69 * @param aScope Scope with external interface implementations that are available. The component
70 * implementation can either oublish itself in this scope or it can decide to
71 * create a new scope with the scope passed in as a parent.
72 * @return Gets an object representing the runtime of the component.
74 Type start(Scope aScope);
78 * @param aRuntime THe runtime part of the component.
80 void stop(Type aRuntime);