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;
18 import java.util.List;
22 * A component represents a part of a system that requires a
23 * number of interfaces and provides a number of interfaces.
25 * The component interface provides the meta-data for a component.
26 * After calling {@link #start(Scope)}, an actual runtime representation of the
27 * component can be created which is independent of this component.
28 * As a special case, the runtime representation may be identical to the
29 * component instance but in general it is not. This allows a component to be
30 * used as a factory for creating objects.
33 * @author Erik Brakkee
35 public interface Component<Type> {
37 * Gets the name of the subsystem.
39 * @return Subsystem name.
44 * Prepends the context with a super context.
46 * @param aContext DOCUMENT ME!
48 void addContext(String aContext);
53 * @return Context or null if not set.
58 * Gets the fully qualified name of the component which includes
59 * the context of the component. This method can only be used after the
60 * component has started.
62 * @return Qualified name.
64 String getQualifiedName();
69 * @return DOCUMENT ME!
74 * @return DOCUMENT ME!
77 * Gets a description of the provided interfaces.
78 * @return Provided interfaces.
80 List<ProvidedInterface> getProvidedInterfaces();
85 * @return DOCUMENT ME!
90 * @return DOCUMENT ME!
93 * Gets a description of the required interfaces.
94 * @return Required interfaces.
96 List<RequiredInterface> getRequiredInterfaces();
99 * Initialises the subsystem by starting all the services that it
100 * described as provided.
102 * @param aScope Scope with external interface implementations that are
103 * available. The component must publish its runtime and its
104 * provided interfaces in this scope.
106 * @return Gets an object representing the runtime of the component.
108 Type start(Scope aScope);
113 * @param aRuntime THe runtime part of the component.
115 void stop(Type aRuntime);