diff options
Diffstat (limited to 'sandbox/ant/sca/branches/tb7/modules/databinding/src/main/java/org/apache/tuscany/sca/databinding/impl/MediatorImpl.java')
| -rw-r--r-- | sandbox/ant/sca/branches/tb7/modules/databinding/src/main/java/org/apache/tuscany/sca/databinding/impl/MediatorImpl.java | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/sandbox/ant/sca/branches/tb7/modules/databinding/src/main/java/org/apache/tuscany/sca/databinding/impl/MediatorImpl.java b/sandbox/ant/sca/branches/tb7/modules/databinding/src/main/java/org/apache/tuscany/sca/databinding/impl/MediatorImpl.java new file mode 100644 index 0000000000..b7ddf87a41 --- /dev/null +++ b/sandbox/ant/sca/branches/tb7/modules/databinding/src/main/java/org/apache/tuscany/sca/databinding/impl/MediatorImpl.java @@ -0,0 +1,182 @@ +/* + * 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.impl; + +import java.security.AccessController; +import java.security.PrivilegedAction; +import java.util.List; +import java.util.Map; + +import org.apache.tuscany.sca.databinding.DataBindingExtensionPoint; +import org.apache.tuscany.sca.databinding.DataPipe; +import org.apache.tuscany.sca.databinding.DataPipeTransformer; +import org.apache.tuscany.sca.databinding.Mediator; +import org.apache.tuscany.sca.databinding.PullTransformer; +import org.apache.tuscany.sca.databinding.PushTransformer; +import org.apache.tuscany.sca.databinding.TransformationContext; +import org.apache.tuscany.sca.databinding.TransformationException; +import org.apache.tuscany.sca.databinding.Transformer; +import org.apache.tuscany.sca.databinding.TransformerExtensionPoint; +import org.apache.tuscany.sca.interfacedef.DataType; +import org.apache.tuscany.sca.interfacedef.Operation; +import org.apache.tuscany.sca.interfacedef.impl.DataTypeImpl; + +/** + * Default Mediator implementation + * + * @version $Rev$ $Date$ + */ +public class MediatorImpl implements Mediator { + + private DataBindingExtensionPoint dataBindings; + private TransformerExtensionPoint transformers; + + public MediatorImpl(DataBindingExtensionPoint dataBindings, TransformerExtensionPoint transformers) { + this.dataBindings = dataBindings; + this.transformers = transformers; + } + + @SuppressWarnings("unchecked") + public Object mediate(Object source, DataType sourceDataType, DataType targetDataType, Map<String, Object> metadata) { + if (sourceDataType == null || sourceDataType.getDataBinding() == null) { + if (source != null) { + Operation operation = (Operation) metadata.get("source.operation"); + sourceDataType = dataBindings.introspectType(source, operation); + } + } + if (sourceDataType == null || targetDataType == 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) { + DataPipeTransformer dataPipeFactory = (i < size - 1) ? (DataPipeTransformer)path.get(++i) : null; + DataPipe dataPipe = dataPipeFactory == null ? null : dataPipeFactory.newInstance(); + ((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<String, Object> metadata) { + DataType sourceType = + (index == 0) ? sourceDataType : new DataTypeImpl<Object>(transformer.getSourceDataBinding(), Object.class, + sourceDataType.getLogical()); + DataType targetType = + (index == size - 1) ? targetDataType : new DataTypeImpl<Object>(transformer.getTargetDataBinding(), + Object.class, targetDataType.getLogical()); + + //FIXME The ClassLoader should be passed in + // Allow privileged access to get ClassLoader. Requires RuntimePermission in security + // policy. + ClassLoader classLoader = AccessController.doPrivileged(new PrivilegedAction<ClassLoader>() { + public ClassLoader run() { + return 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<String, Object> metadata) { + if (source == null) { + // Shortcut for null value + return; + } + if (sourceDataType == null || sourceDataType.getDataBinding() == null) { + Operation operation = (Operation) metadata.get("source.operation"); + sourceDataType = dataBindings.introspectType(source, operation); + } + 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) { + DataPipeTransformer dataPipeFactory = (i < size - 1) ? (DataPipeTransformer)path.get(++i) : null; + DataPipe dataPipe = dataPipeFactory == null ? null : dataPipeFactory.newInstance(); + 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 = transformers.getTransformerChain(sourceId, targetId); + if (path == null) { + TransformationException ex = + new TransformationException("No path found for the transformation: " + sourceId + "->" + targetId); + ex.setSourceDataBinding(sourceId); + ex.setTargetDataBinding(targetId); + throw ex; + } + return path; + } + + public DataBindingExtensionPoint getDataBindings() { + return dataBindings; + } + + public TransformerExtensionPoint getTransformers() { + return transformers; + } + +} |