1 files changed, 131 insertions, 0 deletions
diff --git a/sca-java-2.x/tags/2.0.1-RC1/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/scanner/DefaultContributionScannerExtensionPoint.java b/sca-java-2.x/tags/2.0.1-RC1/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/scanner/DefaultContributionScannerExtensionPoint.java
new file mode 100644
index 0000000000..c5aed5ccd3
--- /dev/null
+++ b/sca-java-2.x/tags/2.0.1-RC1/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/scanner/DefaultContributionScannerExtensionPoint.java
@@ -0,0 +1,131 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.tuscany.sca.contribution.scanner;
+
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.tuscany.sca.contribution.Artifact;
+import org.apache.tuscany.sca.contribution.Contribution;
+import org.apache.tuscany.sca.contribution.ContributionFactory;
+import org.apache.tuscany.sca.contribution.processor.ContributionReadException;
+import org.apache.tuscany.sca.core.ExtensionPointRegistry;
+import org.apache.tuscany.sca.core.FactoryExtensionPoint;
+import org.apache.tuscany.sca.extensibility.ServiceDeclaration;
+
+/**
+ * Default implementation of a contribution scanner extension point.
+ *
+ * @version $Rev$ $Date$
+ */
+public class DefaultContributionScannerExtensionPoint implements ContributionScannerExtensionPoint {
+
+    private Map<String, ContributionScanner> scanners = new HashMap<String, ContributionScanner>();
+    private boolean loaded;
+    private ExtensionPointRegistry registry;
+
+    public DefaultContributionScannerExtensionPoint(ExtensionPointRegistry registry) {
+        this.registry = registry;
+    }
+
+    public void addContributionScanner(ContributionScanner scanner) {
+        scanners.put(scanner.getContributionType(), scanner);
+    }
+
+    public void removeContributionScanner(ContributionScanner scanner) {
+        scanners.remove(scanner.getContributionType());
+    }
+
+    public ContributionScanner getContributionScanner(String contentType) {
+        loadScanners();
+        return scanners.get(contentType);
+    }
+
+    private synchronized void loadScanners() {
+        if (loaded)
+            return;
+
+        // Get the scanner service declarations
+        Collection<ServiceDeclaration> scannerDeclarations;
+        try {
+            scannerDeclarations = registry.getServiceDiscovery().getServiceDeclarations(ContributionScanner.class.getName());
+        } catch (IOException e) {
+            throw new IllegalStateException(e);
+        }
+
+        for (ServiceDeclaration scannerDeclaration: scannerDeclarations) {
+            Map<String, String> attributes = scannerDeclaration.getAttributes();
+
+            // Load a URL artifact scanner
+            String contributionType = attributes.get("type");
+
+            // Create a scanner wrapper and register it
+            ContributionScanner scanner = new LazyContributionScanner(registry, contributionType, scannerDeclaration);
+            addContributionScanner(scanner);
+        }
+
+        loaded = true;
+    }
+
+    /**
+     * A facade for contribution scanners.
+     */
+    private static class LazyContributionScanner implements ContributionScanner {
+        private ExtensionPointRegistry registry;
+        private ServiceDeclaration scannerDeclaration;
+        private String contributionType;
+        private ContributionScanner scanner;
+        private ContributionFactory contributionFactory;
+
+        private LazyContributionScanner(ExtensionPointRegistry registry, String contributionType, ServiceDeclaration scannerDeclaration) {
+            this.registry = registry;
+            this.scannerDeclaration = scannerDeclaration;
+            this.contributionType = contributionType;
+            
+            FactoryExtensionPoint factories = registry.getExtensionPoint(FactoryExtensionPoint.class);
+            this.contributionFactory = factories.getFactory(ContributionFactory.class);
+        }
+
+        public List<Artifact> scan(Contribution contributionSourceURL) throws ContributionReadException {
+            return getScanner().scan(contributionSourceURL);
+        }
+
+        public String getContributionType() {
+            return contributionType;
+        }
+
+        private ContributionScanner getScanner() {
+            if (scanner == null) {
+                try {
+                    Class<ContributionScanner> scannerClass = (Class<ContributionScanner>)scannerDeclaration.loadClass();
+                    Constructor<ContributionScanner> constructor = scannerClass.getConstructor(ContributionFactory.class);
+                    scanner = constructor.newInstance(contributionFactory);
+                } catch (Exception e) {
+                    throw new IllegalStateException(e);
+                }
+            }
+            return scanner;
+        }
+    }
+}