001 // Copyright 2004, 2005 The Apache Software Foundation 002 // 003 // Licensed under the Apache License, Version 2.0 (the "License"); 004 // you may not use this file except in compliance with the License. 005 // You may obtain a copy of the License at 006 // 007 // http://www.apache.org/licenses/LICENSE-2.0 008 // 009 // Unless required by applicable law or agreed to in writing, software 010 // distributed under the License is distributed on an "AS IS" BASIS, 011 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012 // See the License for the specific language governing permissions and 013 // limitations under the License. 014 015 package org.apache.hivemind.internal; 016 017 import org.apache.hivemind.Occurances; 018 import org.apache.hivemind.schema.Schema; 019 020 /** 021 * Sub-interface of {@link org.apache.hivemind.internal.ExtensionPoint} that defines a service 022 * extension point. A service may have a single factory contribution, and any number of interceptor 023 * contributions. 024 * 025 * @author Howard Lewis Ship 026 */ 027 public interface ServicePoint extends ExtensionPoint 028 { 029 /** 030 * Returns the type of the service, the interface the service implements. This may be a 031 * synthetic interface when the interface for the service point is, in fact, a class. 032 */ 033 public Class getServiceInterface(); 034 035 /** 036 * Returns the interface for the service as specified in the descriptor; starting with release 037 * 1.1 it is possible to define a service in terms of a class (as the interface) and a synthetic 038 * interface is generated where appropriate. 039 * 040 * @since 1.1 041 */ 042 043 public Class getDeclaredInterface(); 044 045 /** 046 * Returns the fully qualified class name of the service interface. This is useful so that 047 * loading the actual service interface class can be deferred as late as possible. This is the 048 * value, as specified in the descriptor (except that simple names in the descriptor are 049 * prefixed with the module's package name). Starting in release 1.1, this may be the name of a 050 * ordinary class, not an interface. 051 * 052 * @since 1.1 053 */ 054 055 public String getServiceInterfaceClassName(); 056 057 /** 058 * Obtains the full service implementation for this service extension point, an object that 059 * implements the service interface. Because of the different service models, and because of the 060 * possibility of interceptors, the exact class and object returned can't be specified (and may 061 * vary at different times), but that is not relevant to client code, which is assured that it 062 * can invoke the service methods defined by the service interface. 063 * 064 * @param interfaceClass 065 * the class that the service will be cast to; a check is made that the service is 066 * assignable to the indicated interface. It does not have to, necessarily, match the 067 * service interface (it could be a super-interface, for example). 068 * @return the outermost interceptor for the service, or the core implementation if there are no 069 * interceptors. 070 * @throws org.apache.tapestry.ApplicationRuntimeException 071 * if there is any problem creating the service. 072 */ 073 public Object getService(Class interfaceClass); 074 075 /** 076 * Returns the {@link Schema} used to process any parameters passed to the service. Service 077 * implementation factories and service interceptor factories allow parameters. 078 */ 079 080 public Schema getParametersSchema(); 081 082 /** 083 * Returns the number of parameter object expected; generally this is the default of exactly one ( 084 * {@link Occurances#REQUIRED}). 085 */ 086 public Occurances getParametersCount(); 087 088 /** 089 * Forces the service to be fully instantiated immediately, rather than lazily. 090 */ 091 092 public void forceServiceInstantiation(); 093 }