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author | nash <nash@13f79535-47bb-0310-9956-ffa450edef68> | 2011-04-06 22:03:35 +0000 |
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committer | nash <nash@13f79535-47bb-0310-9956-ffa450edef68> | 2011-04-06 22:03:35 +0000 |
commit | 6d685c8e138af8d18bc71181ec630ccb9a17bdd9 (patch) | |
tree | 75276a59fe0a20761ea59ed312adaeb0a9006c81 /sca-java-1.x/tags/1.6.2-RC1/modules/databinding/src/main/java/org/apache/tuscany/sca/databinding/DefaultTransformerExtensionPoint.java | |
parent | a6eaa1356a4db131566cfe7f7e4c3fe81a0ad0b6 (diff) |
Tag for 1.6.2-RC1
git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@1089647 13f79535-47bb-0310-9956-ffa450edef68
Diffstat (limited to 'sca-java-1.x/tags/1.6.2-RC1/modules/databinding/src/main/java/org/apache/tuscany/sca/databinding/DefaultTransformerExtensionPoint.java')
-rw-r--r-- | sca-java-1.x/tags/1.6.2-RC1/modules/databinding/src/main/java/org/apache/tuscany/sca/databinding/DefaultTransformerExtensionPoint.java | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/sca-java-1.x/tags/1.6.2-RC1/modules/databinding/src/main/java/org/apache/tuscany/sca/databinding/DefaultTransformerExtensionPoint.java b/sca-java-1.x/tags/1.6.2-RC1/modules/databinding/src/main/java/org/apache/tuscany/sca/databinding/DefaultTransformerExtensionPoint.java new file mode 100644 index 0000000000..e99dc2e029 --- /dev/null +++ b/sca-java-1.x/tags/1.6.2-RC1/modules/databinding/src/main/java/org/apache/tuscany/sca/databinding/DefaultTransformerExtensionPoint.java @@ -0,0 +1,306 @@ +/* + * 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.databinding; + +import java.io.IOException; +import java.lang.reflect.Constructor; +import java.util.ArrayList; +import java.util.List; +import java.util.Map; +import java.util.Set; +import java.util.logging.Level; +import java.util.logging.Logger; + +import org.apache.tuscany.sca.databinding.impl.DirectedGraph; +import org.apache.tuscany.sca.extensibility.ServiceDeclaration; +import org.apache.tuscany.sca.extensibility.ServiceDiscovery; + +/** + * @version $Rev$ $Date$ + */ +public class DefaultTransformerExtensionPoint implements TransformerExtensionPoint { + private static final Logger logger = Logger.getLogger(DefaultTransformerExtensionPoint.class.getName()); + private boolean loadedTransformers; + + private final DirectedGraph<Object, Transformer> graph = new DirectedGraph<Object, Transformer>(); + + public DefaultTransformerExtensionPoint() { + } + + public void addTransformer(String sourceType, String resultType, int weight, Transformer transformer, boolean publicTransformer) { + if (logger.isLoggable(Level.FINE)) { + String className = transformer.getClass().getName(); + boolean lazy = false; + boolean pull = (transformer instanceof PullTransformer); + if (transformer instanceof LazyPullTransformer) { + className = ((LazyPullTransformer)transformer).transformerDeclaration.getClassName(); + lazy = true; + } + if (transformer instanceof LazyPushTransformer) { + className = ((LazyPushTransformer)transformer).transformerDeclaration.getClassName(); + lazy = true; + } + + logger.fine("Adding transformer: " + className + + ";source=" + + sourceType + + ",target=" + + resultType + + ",weight=" + + weight + + ",type=" + + (pull ? "pull" : "push") + + ",lazy=" + + lazy); + } + graph.addEdge(sourceType, resultType, transformer, weight, publicTransformer); + } + + public void addTransformer(Transformer transformer, boolean publicTransformer) { + addTransformer(transformer.getSourceDataBinding(), + transformer.getTargetDataBinding(), + transformer.getWeight(), + transformer, publicTransformer); + } + + public boolean removeTransformer(String sourceType, String resultType) { + return graph.removeEdge(sourceType, resultType); + } + + public Transformer getTransformer(String sourceType, String resultType) { + loadTransformers(); + + DirectedGraph<Object, Transformer>.Edge edge = graph.getEdge(sourceType, resultType); + return (edge == null) ? null : edge.getValue(); + } + + /** + * Dynamically load transformers registered under META-INF/services. + * + */ + private synchronized void loadTransformers() { + if (loadedTransformers) { + return; + } + loadedTransformers = true; + loadTransformers(PullTransformer.class); + loadTransformers(PushTransformer.class); + + } + + /** + * Dynamically load transformers registered under META-INF/services. + * + * @param transformerClass + */ + private synchronized void loadTransformers(Class<?> transformerClass) { + + // Get the transformer service declarations + Set<ServiceDeclaration> transformerDeclarations; + + try { + transformerDeclarations = ServiceDiscovery.getInstance().getServiceDeclarations(transformerClass); + + } catch (IOException e) { + throw new IllegalStateException(e); + } + + // Load transformers + for (ServiceDeclaration transformerDeclaration : transformerDeclarations) { + Map<String, String> attributes = transformerDeclaration.getAttributes(); + + String source = attributes.get("source"); + String target = attributes.get("target"); + int weight = Integer.valueOf(attributes.get("weight")); + String b = attributes.get("public"); + boolean pub = true; + if (b != null) { + pub = Boolean.valueOf(b); + } + + // Create a transformer wrapper and register it + Transformer transformer; + if (transformerClass == PullTransformer.class) { + transformer = new LazyPullTransformer(source, target, weight, transformerDeclaration); + } else { + transformer = new LazyPushTransformer(source, target, weight, transformerDeclaration); + } + addTransformer(transformer, pub); + } + } + + /** + * A transformer facade allowing transformers to be lazily loaded + * and initialized. + */ + private static class LazyPullTransformer implements PullTransformer<Object, Object> { + + private String source; + private String target; + private int weight; + private ServiceDeclaration transformerDeclaration; + private PullTransformer<Object, Object> transformer; + + public LazyPullTransformer(String source, String target, int weight, ServiceDeclaration transformerDeclaration) { + this.source = source; + this.target = target; + this.weight = weight; + this.transformerDeclaration = transformerDeclaration; + } + + /** + * Load and instantiate the transformer class. + * + * @return The transformer. + */ + @SuppressWarnings("unchecked") + private PullTransformer<Object, Object> getTransformer() { + if (transformer == null) { + try { + Class<PullTransformer<Object, Object>> transformerClass = + (Class<PullTransformer<Object, Object>>)transformerDeclaration.loadClass(); + Constructor<PullTransformer<Object, Object>> constructor = transformerClass.getConstructor(); + transformer = constructor.newInstance(); + } catch (Exception e) { + throw new IllegalStateException(e); + } + } + return transformer; + } + + public String getSourceDataBinding() { + return source; + } + + public String getTargetDataBinding() { + return target; + } + + public int getWeight() { + return weight; + } + + public Object transform(Object source, TransformationContext context) { + return getTransformer().transform(source, context); + } + + @Override + public String toString() { + StringBuffer sb = new StringBuffer(super.toString()); + sb.append(";className=").append(transformerDeclaration.getClassName()); + return sb.toString(); + } + } + + /** + * A transformer facade allowing transformers to be lazily loaded + * and initialized. + */ + private static class LazyPushTransformer implements PushTransformer<Object, Object> { + + private String source; + private String target; + private int weight; + private ServiceDeclaration transformerDeclaration; + private PushTransformer<Object, Object> transformer; + + public LazyPushTransformer(String source, String target, int weight, ServiceDeclaration transformerDeclaration) { + this.source = source; + this.target = target; + this.weight = weight; + this.transformerDeclaration = transformerDeclaration; + } + + /** + * Load and instantiate the transformer class. + * + * @return The transformer. + */ + @SuppressWarnings("unchecked") + private PushTransformer<Object, Object> getTransformer() { + if (transformer == null) { + try { + Class<PushTransformer<Object, Object>> transformerClass = + (Class<PushTransformer<Object, Object>>)transformerDeclaration.loadClass(); + Constructor<PushTransformer<Object, Object>> constructor = transformerClass.getConstructor(); + transformer = constructor.newInstance(); + } catch (Exception e) { + throw new IllegalStateException(e); + } + } + return transformer; + } + + public String getSourceDataBinding() { + return source; + } + + public String getTargetDataBinding() { + return target; + } + + public int getWeight() { + return weight; + } + + public void transform(Object source, Object sink, TransformationContext context) { + getTransformer().transform(source, sink, context); + } + + @Override + public String toString() { + StringBuffer sb = new StringBuffer(super.toString()); + sb.append(";className=").append(transformerDeclaration.getClassName()); + return sb.toString(); + } + } + + //FIXME The following methods should be on a different class from + // extension point + + public List<Transformer> getTransformerChain(String sourceType, String resultType) { + loadTransformers(); + + String source = sourceType; + String result = resultType; + List<Transformer> transformers = new ArrayList<Transformer>(); + // First check if there is a direct path, if yes, use it regardless of the weight + DirectedGraph<Object, Transformer>.Edge link = graph.getEdge(sourceType, resultType); + if (link != null) { + transformers.add(link.getValue()); + } else { + DirectedGraph<Object, Transformer>.Path path = graph.getShortestPath(source, result); + if (path == null) { + return null; + } + for (DirectedGraph<Object, Transformer>.Edge edge : path.getEdges()) { + transformers.add(edge.getValue()); + } + } + return transformers; + } + + @Override + public String toString() { + loadTransformers(); + + return graph.toString(); + } + +} |