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Diffstat (limited to 'branches/sca-java-integration/sca/kernel/core/src/main/java/org/apache/tuscany/core/databinding/impl/MediatorImpl.java')
-rw-r--r-- | branches/sca-java-integration/sca/kernel/core/src/main/java/org/apache/tuscany/core/databinding/impl/MediatorImpl.java | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/branches/sca-java-integration/sca/kernel/core/src/main/java/org/apache/tuscany/core/databinding/impl/MediatorImpl.java b/branches/sca-java-integration/sca/kernel/core/src/main/java/org/apache/tuscany/core/databinding/impl/MediatorImpl.java new file mode 100644 index 0000000000..2b6d871472 --- /dev/null +++ b/branches/sca-java-integration/sca/kernel/core/src/main/java/org/apache/tuscany/core/databinding/impl/MediatorImpl.java @@ -0,0 +1,185 @@ +/* + * 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.core.databinding.impl; + +import java.util.List; +import java.util.Map; + +import org.apache.tuscany.spi.annotation.Autowire; +import org.apache.tuscany.spi.databinding.DataBindingRegistry; +import org.apache.tuscany.spi.databinding.DataPipe; +import org.apache.tuscany.spi.databinding.Mediator; +import org.apache.tuscany.spi.databinding.PullTransformer; +import org.apache.tuscany.spi.databinding.PushTransformer; +import org.apache.tuscany.spi.databinding.TransformationContext; +import org.apache.tuscany.spi.databinding.TransformationException; +import org.apache.tuscany.spi.databinding.Transformer; +import org.apache.tuscany.spi.databinding.TransformerRegistry; +import org.apache.tuscany.spi.model.DataType; +import org.osoa.sca.annotations.Scope; + +/** + * Default Mediator implementation + */ +@Scope("COMPOSITE") +public class MediatorImpl implements Mediator { + + private DataBindingRegistry dataBindingRegistry; + + private TransformerRegistry transformerRegistry; + + @Autowire + public void setTransformerRegistry(TransformerRegistry transformerRegistry) { + this.transformerRegistry = transformerRegistry; + } + + /** + * @param dataBindingRegistry the dataBindingRegistry to set + */ + @Autowire + public void setDataBindingRegistry(DataBindingRegistry dataBindingRegistry) { + this.dataBindingRegistry = dataBindingRegistry; + } + + /** + * @see org.apache.tuscany.spi.databinding.Mediator#mediate(java.lang.Object, + * org.apache.tuscany.spi.model.DataType, + * org.apache.tuscany.spi.model.DataType, Map) + */ + @SuppressWarnings("unchecked") + public Object mediate(Object source, + DataType sourceDataType, + DataType targetDataType, + Map<Class<?>, Object> metadata) { + if (sourceDataType == null) { + sourceDataType = dataBindingRegistry.introspectType(source); + } + if (sourceDataType == null) { + return source; + } else if (sourceDataType.equals(targetDataType)) { + return source; + } + + List<Transformer> path = getTransformerChain(sourceDataType, targetDataType); + + Object result = source; + int size = path.size(); + int i = 0; + while (i < size) { + Transformer transformer = path.get(i); + TransformationContext context = + createTransformationContext(sourceDataType, targetDataType, size, i, transformer, metadata); + // the source and target type + if (transformer instanceof PullTransformer) { + // For intermediate node, set data type to null + result = ((PullTransformer)transformer).transform(result, context); + } else if (transformer instanceof PushTransformer) { + DataPipe dataPipe = (i < size - 1) ? (DataPipe)path.get(++i) : null; + ((PushTransformer)transformer).transform(result, dataPipe.getSink(), context); + result = dataPipe.getResult(); + } + i++; + } + + return result; + } + + private TransformationContext createTransformationContext(DataType sourceDataType, + DataType targetDataType, + int size, + int index, + Transformer transformer, + Map<Class<?>, Object> metadata) { + DataType sourceType = + (index == 0) ? sourceDataType : new DataType<Object>(transformer.getSourceDataBinding(), + Object.class, null); + DataType targetType = + (index == size - 1) ? targetDataType : new DataType<Object>(transformer.getTargetDataBinding(), + Object.class, null); + ClassLoader classLoader = Thread.currentThread().getContextClassLoader(); + TransformationContext context = + new TransformationContextImpl(sourceType, targetType, classLoader, metadata); + return context; + } + + @SuppressWarnings("unchecked") + public void mediate(Object source, + Object target, + DataType sourceDataType, + DataType targetDataType, + Map<Class<?>, Object> metadata) { + if (source == null) { + // Shortcut for null value + return; + } + if (sourceDataType == null) { + sourceDataType = dataBindingRegistry.introspectType(source); + } + if (sourceDataType == null) { + return; + } else if (sourceDataType.equals(targetDataType)) { + return; + } + + List<Transformer> path = getTransformerChain(sourceDataType, targetDataType); + Object result = source; + int size = path.size(); + for (int i = 0; i < size; i++) { + Transformer transformer = path.get(i); + TransformationContext context = + createTransformationContext(sourceDataType, targetDataType, size, i, transformer, metadata); + + if (transformer instanceof PullTransformer) { + result = ((PullTransformer)transformer).transform(result, context); + } else if (transformer instanceof PushTransformer) { + DataPipe dataPipe = (i < size - 1) ? (DataPipe)path.get(++i) : null; + Object sink = dataPipe != null ? dataPipe.getSink() : target; + ((PushTransformer)transformer).transform(result, sink, context); + result = (dataPipe != null) ? dataPipe.getResult() : null; + } + } + } + + private List<Transformer> getTransformerChain(DataType sourceDataType, DataType targetDataType) { + String sourceId = sourceDataType.getDataBinding(); + String targetId = targetDataType.getDataBinding(); + List<Transformer> path = transformerRegistry.getTransformerChain(sourceId, targetId); + if (path == null) { + TransformationException ex = new TransformationException("No path found for the transformation"); + ex.addContextName("Source: " + sourceId); + ex.addContextName("Target: " + targetId); + throw ex; + } + return path; + } + + /** + * @return the dataBindingRegistry + */ + public DataBindingRegistry getDataBindingRegistry() { + return dataBindingRegistry; + } + + /** + * @return the transformerRegistry + */ + public TransformerRegistry getTransformerRegistry() { + return transformerRegistry; + } +} |