Now basing the implementation on a component graph.

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

diff --git a/system/general/src/main/java/org/wamblee/system/graph/component/CheckStartupDependenciesVisitor.java b/system/general/src/main/java/org/wamblee/system/graph/component/CheckStartupDependenciesVisitor.java
new file mode 100644 (file)
index 0000000..5b50e09
--- /dev/null
+++ b/system/general/src/main/java/org/wamblee/system/graph/component/CheckStartupDependenciesVisitor.java
@@ -0,0 +1,57 @@
+/*
+ * 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 java.util.ArrayList;
+import java.util.List;
+
+import org.wamblee.system.core.SystemAssemblyException;
+import org.wamblee.system.graph.Edge;
+import org.wamblee.system.graph.Graph;
+import org.wamblee.system.graph.Node;
+import org.wamblee.system.graph.Visitor;
+
+public class CheckStartupDependenciesVisitor implements Visitor {
+    
+    private Graph _graph; 
+    private List<Node> _available; 
+    
+    public CheckStartupDependenciesVisitor(Graph aGraph) { 
+        _graph = aGraph; 
+        _available = new ArrayList<Node>();
+    }
+
+    @Override
+    public void visitEdge(Edge aEdge) {
+        // Empty
+    }
+
+    @Override
+    public void visitNode(Node aNode) {
+        List<Edge> edges = _graph.findOutgoing(aNode);
+        
+        // check dependencies.
+        for (Edge edge: edges) { 
+            Node dep = edge.getTo();
+            if ( !_available.contains(dep)) { 
+                throw new SystemAssemblyException(aNode + ": required dependency '" + dep + "' was not started");
+            }
+        }
+        
+        _available.add(aNode);
+    }
+
+}