wamblee.org Git - utils/blob - system/general/src/main/java/org/wamblee/system/graph/component/CheckExternallyRequiredVisitor.java

   1 /*
   2  * Copyright 2008 the original author or authors.
   3  *
   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
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  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.
  15  */
  16 package org.wamblee.system.graph.component;
  17
  18 import org.apache.commons.logging.Log;
  19 import org.apache.commons.logging.LogFactory;
  20
  21 import org.wamblee.system.core.SystemAssemblyException;
  22 import org.wamblee.system.graph.Edge;
  23 import org.wamblee.system.graph.Graph;
  24 import org.wamblee.system.graph.Node;
  25 import org.wamblee.system.graph.Visitor;
  26
  27 import java.util.List;
  28
  29 /**
  30  * Visitor that checks whether all required external interfaces of the container
  31  * are provided.
  32  *
  33  * @author Erik Brakkee
  34  */
  35 public class CheckExternallyRequiredVisitor implements Visitor {
  36     private Log LOG = LogFactory.getLog(CheckExternallyRequiredVisitor.class);
  37
  38     private Graph graph;
  39
  40     /**
  41      * Creates a new CheckExternallyRequiredVisitor object.
  42      *
  43      */
  44     public CheckExternallyRequiredVisitor(Graph aGraph) {
  45         graph = aGraph;
  46     }
  47
  48     @Override
  49     public void visitEdge(Edge aEdge) {
  50         // Empty.
  51     }
  52
  53     @Override
  54     public void visitNode(Node aNode) {
  55         if (aNode instanceof ExternalRequiredInterfaceNode) {
  56             ExternalRequiredInterfaceNode required = (ExternalRequiredInterfaceNode) aNode;
  57
  58             if (!required.getRequired().isOptional() &&
  59                 (required.getRequired().getProvider() == null)) {
  60                 throw new SystemAssemblyException(aNode +
  61                     ": External required interface is not provided");
  62             }
  63
  64             List<Edge> edges = graph.findIncoming(aNode);
  65
  66             if (edges.isEmpty()) {
  67                 LOG.warn(aNode + ": Superfluous required interface");
  68             }
  69
  70             for (Edge edge : edges) {
  71                 Node from = edge.getFrom();
  72                 assert from instanceof RequiredInterfaceNode;
  73
  74                 RequiredInterfaceNode reqNode = (RequiredInterfaceNode) from;
  75
  76                 if (!reqNode.getRequired().isOptional() &&
  77                     required.getRequired().isOptional()) {
  78                     throw new SystemAssemblyException(
  79                         aNode +
  80                             ": externally required interface is optional but a corresponding internal required interface is mandatory: " +
  81                             reqNode);
  82                 }
  83             }
  84         }
  85     }
  86 }