Now basing the implementation on a component graph.

[utils] / system / general / src / main / java / org / wamblee / system / graph / component / LinkVisitor.java

diff --git a/system/general/src/main/java/org/wamblee/system/graph/component/LinkVisitor.java b/system/general/src/main/java/org/wamblee/system/graph/component/LinkVisitor.java
new file mode 100644 (file)
index 0000000..088f058
--- /dev/null
+++ b/system/general/src/main/java/org/wamblee/system/graph/component/LinkVisitor.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright 2008 the original author or authors.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.wamblee.system.graph.component;
+
+import org.wamblee.system.core.ProvidedInterface;
+import org.wamblee.system.core.SystemAssemblyException;
+import org.wamblee.system.graph.DefaultEdge;
+import org.wamblee.system.graph.Edge;
+import org.wamblee.system.graph.Node;
+import org.wamblee.system.graph.Visitor;
+
+/**
+ * Visitor that creates links between required and provided interfaces as
+ * described by the edges in the graph.
+ * 
+ * @author Erik Brakkee
+ * 
+ */
+public class LinkVisitor implements Visitor {
+
+    @Override
+    public void visitEdge(Edge aEdge) {
+        Node from = aEdge.getFrom();
+        Node to = aEdge.getTo();
+        if (from instanceof RequiredInterfaceNode) {
+            RequiredInterfaceNode required = (RequiredInterfaceNode) from;
+            if (to instanceof ProvidedInterfaceNode) {
+
+                ProvidedInterfaceNode provided = (ProvidedInterfaceNode) to;
+                required.getRequired().setProvider(provided.getProvided());
+
+            } else if (to instanceof ExternalRequiredInterfaceNode) {
+                ExternalRequiredInterfaceNode external = (ExternalRequiredInterfaceNode) to;
+                ProvidedInterface provider = external.getRequired()
+                        .getProvider();
+                if (provider == null && !required.getRequired().isOptional()) {
+                    throw new SystemAssemblyException("Mandatory interface '"
+                            + from + "' is not provided.");
+                }
+                if ( provider != null ) { 
+                    required.getRequired().setProvider(provider);
+                }
+            }
+        } else if (from instanceof ProvidedInterfaceNode) {
+            // Provided interfaces can only be published after the system has
+            // started.
+        }
+    }
+
+    @Override
+    public void visitNode(Node aNode) {
+        // Empty.
+    }
+
+}