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Diffstat (limited to 'sca-java-2.x/branches/2.0/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/scanner/DefaultContributionScannerExtensionPoint.java')
-rw-r--r-- | sca-java-2.x/branches/2.0/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/scanner/DefaultContributionScannerExtensionPoint.java | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/sca-java-2.x/branches/2.0/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/scanner/DefaultContributionScannerExtensionPoint.java b/sca-java-2.x/branches/2.0/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/branches/2.0/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; + } + } +} |