diff options
Diffstat (limited to 'sca-java-1.x/tags/1.4/modules/core-databinding/src/main/java/org/apache/tuscany/sca/core/databinding/wire')
3 files changed, 727 insertions, 0 deletions
diff --git a/sca-java-1.x/tags/1.4/modules/core-databinding/src/main/java/org/apache/tuscany/sca/core/databinding/wire/DataBindingRuntimeWireProcessor.java b/sca-java-1.x/tags/1.4/modules/core-databinding/src/main/java/org/apache/tuscany/sca/core/databinding/wire/DataBindingRuntimeWireProcessor.java new file mode 100644 index 0000000000..b41c7fb012 --- /dev/null +++ b/sca-java-1.x/tags/1.4/modules/core-databinding/src/main/java/org/apache/tuscany/sca/core/databinding/wire/DataBindingRuntimeWireProcessor.java @@ -0,0 +1,195 @@ +/* + * 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.core.databinding.wire; + +import java.util.List; + +import org.apache.tuscany.sca.assembly.ComponentReference; +import org.apache.tuscany.sca.databinding.DataBindingExtensionPoint; +import org.apache.tuscany.sca.databinding.Mediator; +import org.apache.tuscany.sca.interfacedef.DataType; +import org.apache.tuscany.sca.interfacedef.FaultExceptionMapper; +import org.apache.tuscany.sca.interfacedef.InterfaceContract; +import org.apache.tuscany.sca.interfacedef.Operation; +import org.apache.tuscany.sca.invocation.Interceptor; +import org.apache.tuscany.sca.invocation.InvocationChain; +import org.apache.tuscany.sca.invocation.Phase; +import org.apache.tuscany.sca.runtime.RuntimeWire; +import org.apache.tuscany.sca.runtime.RuntimeWireProcessor; + +/** + * This processor is responsible to add an interceptor to invocation chain if + * the source and target operations have different databinding requirements + * + * @version $Rev$ $Date$ + */ +public class DataBindingRuntimeWireProcessor implements RuntimeWireProcessor { + private Mediator mediator; + private DataBindingExtensionPoint dataBindings; + private FaultExceptionMapper faultExceptionMapper; + + public DataBindingRuntimeWireProcessor(Mediator mediator, + DataBindingExtensionPoint dataBindings, + FaultExceptionMapper faultExceptionMapper) { + super(); + this.mediator = mediator; + this.dataBindings = dataBindings; + this.faultExceptionMapper = faultExceptionMapper; + } + + public boolean isTransformationRequired(DataType source, DataType target) { + if (source == null || target == null) { // void return type + return false; + } + if (source == target) { + return false; + } + + // Output type can be null + if (source == null && target == null) { + return false; + } else if (source == null || target == null) { + return true; + } + String sourceDataBinding = source.getDataBinding(); + String targetDataBinding = target.getDataBinding(); + if (sourceDataBinding == targetDataBinding) { + return false; + } + if (sourceDataBinding == null || targetDataBinding == null) { + // TODO: If any of the databinding is null, then no transformation + return false; + } + return !sourceDataBinding.equals(targetDataBinding); + } + + public boolean isTransformationRequired(Operation source, Operation target) { + if (source == target) { + return false; + } + + if (source.isWrapperStyle() != target.isWrapperStyle()) { + return true; + } + + // Check output type + DataType sourceOutputType = source.getOutputType(); + DataType targetOutputType = target.getOutputType(); + + // Note the target output type is now the source for checking + // compatibility + if (isTransformationRequired(targetOutputType, sourceOutputType)) { + return true; + } + + List<DataType> sourceInputType = source.getInputType().getLogical(); + List<DataType> targetInputType = target.getInputType().getLogical(); + + int size = sourceInputType.size(); + if (size != targetInputType.size()) { + // TUSCANY-1682: The wrapper style may have different arguments + return true; + } + for (int i = 0; i < size; i++) { + if (isTransformationRequired(sourceInputType.get(i), targetInputType.get(i))) { + return true; + } + } + + return false; + } + + private boolean isTransformationRequired(InterfaceContract sourceContract, + Operation sourceOperation, + InterfaceContract targetContract, + Operation targetOperation) { + if (targetContract == null) { + targetContract = sourceContract; + } + if (sourceContract == targetContract) { + return false; + } + return isTransformationRequired(sourceOperation, targetOperation); + } + + public void process(RuntimeWire wire) { + InterfaceContract sourceContract = wire.getSource().getInterfaceContract(); + InterfaceContract targetContract = wire.getTarget().getInterfaceContract(); + if (targetContract == null) { + targetContract = sourceContract; + } + + if (!sourceContract.getInterface().isRemotable()) { + return; + } + List<InvocationChain> chains = wire.getInvocationChains(); + for (InvocationChain chain : chains) { + Operation sourceOperation = chain.getSourceOperation(); + Operation targetOperation = chain.getTargetOperation(); + + Interceptor interceptor = null; + if (isTransformationRequired(sourceContract, sourceOperation, targetContract, targetOperation)) { + // Add the interceptor to the source side because multiple + // references can be wired to the same service + interceptor = + new DataTransformationInterceptor(wire, sourceOperation, targetOperation, mediator, + faultExceptionMapper); + } else { + // assume pass-by-values copies are required if interfaces are remotable and there is no data binding + // transformation, i.e. a transformation will result in a copy so another pass-by-value copy is unnecessary + if (!isOnMessage(targetOperation) && isRemotable(chain, sourceOperation, targetOperation)) { + interceptor = + new PassByValueInterceptor(dataBindings, faultExceptionMapper, chain, targetOperation); + } + } + if (interceptor != null) { + String phase = + (wire.getSource().getContract() instanceof ComponentReference) ? Phase.REFERENCE_INTERFACE + : Phase.SERVICE_INTERFACE; + chain.addInterceptor(phase, interceptor); + } + } + + } + + /** + * FIXME: TUSCANY-2586, temporary work around till the JIRA is fixed to prevent + * the PassByValueInterceptor being used for services when the binding protocol + * doesn't need the copies done. + */ + protected boolean isOnMessage(Operation op) { + return "onMessage".equals(op.getName()); + } + + /** + * Pass-by-value copies are required if the interfaces are remotable unless the + * implementation uses the @AllowsPassByReference annotation. + */ + protected boolean isRemotable(InvocationChain chain, Operation sourceOperation, Operation targetOperation) { + if (!sourceOperation.getInterface().isRemotable()) { + return false; + } + if (!targetOperation.getInterface().isRemotable()) { + return false; + } + return true; + } + +} diff --git a/sca-java-1.x/tags/1.4/modules/core-databinding/src/main/java/org/apache/tuscany/sca/core/databinding/wire/DataTransformationInterceptor.java b/sca-java-1.x/tags/1.4/modules/core-databinding/src/main/java/org/apache/tuscany/sca/core/databinding/wire/DataTransformationInterceptor.java new file mode 100644 index 0000000000..5814f3d215 --- /dev/null +++ b/sca-java-1.x/tags/1.4/modules/core-databinding/src/main/java/org/apache/tuscany/sca/core/databinding/wire/DataTransformationInterceptor.java @@ -0,0 +1,264 @@ +/* + * 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.core.databinding.wire; + +import java.lang.reflect.InvocationTargetException; +import java.util.HashMap; +import java.util.Map; + +import javax.xml.namespace.QName; + +import org.apache.tuscany.sca.databinding.DataBinding; +import org.apache.tuscany.sca.databinding.Mediator; +import org.apache.tuscany.sca.interfacedef.DataType; +import org.apache.tuscany.sca.interfacedef.FaultExceptionMapper; +import org.apache.tuscany.sca.interfacedef.Operation; +import org.apache.tuscany.sca.interfacedef.impl.DataTypeImpl; +import org.apache.tuscany.sca.interfacedef.util.FaultException; +import org.apache.tuscany.sca.interfacedef.util.XMLType; +import org.apache.tuscany.sca.invocation.DataExchangeSemantics; +import org.apache.tuscany.sca.invocation.Interceptor; +import org.apache.tuscany.sca.invocation.Invoker; +import org.apache.tuscany.sca.invocation.Message; +import org.apache.tuscany.sca.runtime.RuntimeWire; +import org.osoa.sca.ServiceRuntimeException; + +/** + * An interceptor to transform data across databindings on the wire + * + * @version $Rev$ $Date$ + */ +public class DataTransformationInterceptor implements Interceptor, DataExchangeSemantics { + private Invoker next; + + private Operation sourceOperation; + + private Operation targetOperation; + private RuntimeWire wire; + private Mediator mediator; + private FaultExceptionMapper faultExceptionMapper; + + public DataTransformationInterceptor(RuntimeWire wire, + Operation sourceOperation, + Operation targetOperation, + Mediator mediator, + FaultExceptionMapper faultExceptionMapper) { + super(); + this.sourceOperation = sourceOperation; + this.targetOperation = targetOperation; + this.mediator = mediator; + this.wire = wire; + this.faultExceptionMapper = faultExceptionMapper; + } + + public Invoker getNext() { + return next; + } + + public Message invoke(Message msg) { + Object input = transform(msg.getBody(), sourceOperation.getInputType(), targetOperation.getInputType(), false); + msg.setBody(input); + Message resultMsg = next.invoke(msg); + Object result = resultMsg.getBody(); + if (sourceOperation.isNonBlocking()) { + // Not to reset the message body + return resultMsg; + } + + // FIXME: Should we fix the Operation model so that getOutputType + // returns DataType<DataType<T>>? + DataType<DataType> targetType = + new DataTypeImpl<DataType>(DataBinding.IDL_OUTPUT, Object.class, targetOperation.getOutputType()); + + DataType<DataType> sourceType = + new DataTypeImpl<DataType>(DataBinding.IDL_OUTPUT, Object.class, sourceOperation.getOutputType()); + + if (resultMsg.isFault()) { + + // FIXME: We need to figure out what fault type it is and then + // transform it + // back the source fault type + // throw new InvocationRuntimeException((Throwable) result); + + if ((result instanceof Exception) && !(result instanceof RuntimeException)) { + // FIXME: How to match fault data to a fault type for the + // operation? + + // If the result is from an InvocationTargetException look at + // the actual cause. + if (result instanceof InvocationTargetException) { + result = ((InvocationTargetException)result).getCause(); + } + DataType targetDataType = null; + for (DataType exType : targetOperation.getFaultTypes()) { + if (((Class)exType.getPhysical()).isInstance(result)) { + if (result instanceof FaultException) { + DataType faultType = (DataType)exType.getLogical(); + if (((FaultException)result).isMatchingType(faultType.getLogical())) { + targetDataType = exType; + break; + } + } else { + targetDataType = exType; + break; + } + } + } + + /* + if (targetDataType == null) { + // Not a business exception + return resultMsg; + } + */ + + DataType targetFaultType = getFaultType(targetDataType); + if (targetFaultType == null) { + // No matching fault type, it's a system exception + Throwable cause = (Throwable) result; + throw new ServiceRuntimeException(cause); + } + + // FIXME: How to match a source fault type to a target fault + // type? + DataType sourceDataType = null; + DataType sourceFaultType = null; + for (DataType exType : sourceOperation.getFaultTypes()) { + DataType faultType = getFaultType(exType); + // Match by the QName (XSD element) of the fault type + if (faultType != null && typesMatch(targetFaultType.getLogical(), faultType.getLogical())) { + sourceDataType = exType; + sourceFaultType = faultType; + break; + } + } + + if (sourceFaultType == null) { + // No matching fault type, it's a system exception + Throwable cause = (Throwable) result; + throw new ServiceRuntimeException(cause); + } + + Object newResult = + transformException(result, targetDataType, sourceDataType, targetFaultType, sourceFaultType); + if (newResult != result) { + resultMsg.setFaultBody(newResult); + } + } + + } else { + assert !(result instanceof Throwable) : "Expected messages that are not throwable " + result; + + Object newResult = transform(result, targetType, sourceType, true); + if (newResult != result) { + resultMsg.setBody(newResult); + } + } + + return resultMsg; + } + + private Object transform(Object source, DataType sourceType, DataType targetType, boolean isResponse) { + if (sourceType == targetType || (sourceType != null && sourceType.equals(targetType))) { + return source; + } + Map<String, Object> metadata = new HashMap<String, Object>(); + metadata.put("source.operation", isResponse ? targetOperation : sourceOperation); + metadata.put("target.operation", isResponse ? sourceOperation : targetOperation); + metadata.put("wire", wire); + return mediator.mediate(source, sourceType, targetType, metadata); + } + + private DataType getFaultType(DataType exceptionType) { + return exceptionType == null ? null : (DataType)exceptionType.getLogical(); + } + + private boolean typesMatch(Object first, Object second) { + if (first.equals(second)) { + return true; + } + if (first instanceof XMLType && second instanceof XMLType) { + XMLType t1 = (XMLType)first; + XMLType t2 = (XMLType)second; + // TUSCANY-2113, we should compare element names only + return matches(t1.getElementName(), t2.getElementName()); + } + return false; + } + + /** + * @param qn1 + * @param qn2 + */ + private boolean matches(QName qn1, QName qn2) { + if (qn1 == qn2) { + return true; + } + if (qn1 == null || qn2 == null) { + return false; + } + String ns1 = qn1.getNamespaceURI(); + String ns2 = qn2.getNamespaceURI(); + String e1 = qn1.getLocalPart(); + String e2 = qn2.getLocalPart(); + if (e1.equals(e2) && (ns1.equals(ns2) || ns1.equals(ns2 + "/") || ns2.equals(ns1 + "/"))) { + // Tolerating the trailing / which is required by JAX-WS java package --> xml ns mapping + return true; + } + return false; + } + + /** + * @param source The source exception + * @param sourceExType The data type for the source exception + * @param targetExType The data type for the target exception + * @param sourceType The fault type for the source + * @param targetType The fault type for the target + * @return + */ + private Object transformException(Object source, + DataType sourceExType, + DataType targetExType, + DataType sourceType, + DataType targetType) { + if (sourceType == targetType || (sourceType != null && sourceType.equals(targetType))) { + return source; + } + Map<String, Object> metadata = new HashMap<String, Object>(); + metadata.put("source.operation", targetOperation); + metadata.put("target.operation", sourceOperation); + metadata.put("wire", wire); + DataType<DataType> eSourceDataType = + new DataTypeImpl<DataType>("idl:fault", sourceExType.getPhysical(), sourceType); + DataType<DataType> eTargetDataType = + new DataTypeImpl<DataType>("idl:fault", targetExType.getPhysical(), targetType); + + return mediator.mediate(source, eSourceDataType, eTargetDataType, metadata); + } + + public void setNext(Invoker next) { + this.next = next; + } + + public boolean allowsPassByReference() { + return true; + } + +} diff --git a/sca-java-1.x/tags/1.4/modules/core-databinding/src/main/java/org/apache/tuscany/sca/core/databinding/wire/PassByValueInterceptor.java b/sca-java-1.x/tags/1.4/modules/core-databinding/src/main/java/org/apache/tuscany/sca/core/databinding/wire/PassByValueInterceptor.java new file mode 100644 index 0000000000..3586f54d71 --- /dev/null +++ b/sca-java-1.x/tags/1.4/modules/core-databinding/src/main/java/org/apache/tuscany/sca/core/databinding/wire/PassByValueInterceptor.java @@ -0,0 +1,268 @@ +/* + * 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.core.databinding.wire; + +import java.io.Serializable; +import java.lang.reflect.Array; +import java.lang.reflect.InvocationTargetException; +import java.lang.reflect.Method; +import java.net.URI; +import java.util.IdentityHashMap; +import java.util.List; +import java.util.Map; +import java.util.UUID; + +import javax.xml.namespace.QName; + +import org.apache.tuscany.sca.databinding.DataBinding; +import org.apache.tuscany.sca.databinding.DataBindingExtensionPoint; +import org.apache.tuscany.sca.databinding.javabeans.JavaBeansDataBinding; +import org.apache.tuscany.sca.databinding.jaxb.JAXBDataBinding; +import org.apache.tuscany.sca.interfacedef.DataType; +import org.apache.tuscany.sca.interfacedef.FaultExceptionMapper; +import org.apache.tuscany.sca.interfacedef.Operation; +import org.apache.tuscany.sca.interfacedef.impl.DataTypeImpl; +import org.apache.tuscany.sca.interfacedef.util.XMLType; +import org.apache.tuscany.sca.invocation.Interceptor; +import org.apache.tuscany.sca.invocation.InvocationChain; +import org.apache.tuscany.sca.invocation.Invoker; +import org.apache.tuscany.sca.invocation.Message; +import org.osoa.sca.ServiceRuntimeException; + +/** + * Implementation of an interceptor that enforces pass-by-value semantics + * on operation invocations by copying the operation input and output data. + * + * @version $Rev$ $Date$ + */ +public class PassByValueInterceptor implements Interceptor { + + private DataBindingExtensionPoint dataBindings; + private FaultExceptionMapper faultExceptionMapper; + + private DataBinding[] inputDataBindings; + private DataBinding outputDataBinding; + private DataBinding javaBeanDataBinding; + private DataBinding jaxbDataBinding; + private Operation operation; + private Invoker nextInvoker; + private InvocationChain chain; + + /** + * Constructs a new PassByValueInterceptor. + * @param dataBindings databinding extension point + * @param operation the intercepted operation + */ + public PassByValueInterceptor(DataBindingExtensionPoint dataBindings, + FaultExceptionMapper faultExceptionMapper, + InvocationChain chain, + Operation operation) { + this.chain = chain; + this.operation = operation; + + // Cache data bindings to use + this.dataBindings = dataBindings; + this.faultExceptionMapper = faultExceptionMapper; + + jaxbDataBinding = dataBindings.getDataBinding(JAXBDataBinding.NAME); + javaBeanDataBinding = dataBindings.getDataBinding(JavaBeansDataBinding.NAME); + + // Determine the input databindings + if (operation.getInputType() != null) { + List<DataType> inputTypes = operation.getInputType().getLogical(); + inputDataBindings = new DataBinding[inputTypes.size()]; + int i = 0; + for (DataType inputType : inputTypes) { + String id = inputType.getDataBinding(); + inputDataBindings[i++] = dataBindings.getDataBinding(id); + } + } + + // Determine the output databinding + if (operation.getOutputType() != null) { + String id = operation.getOutputType().getDataBinding(); + outputDataBinding = dataBindings.getDataBinding(id); + } + } + + public Message invoke(Message msg) { + if (chain.allowsPassByReference()) { + return nextInvoker.invoke(msg); + } + + msg.setBody(copy((Object[])msg.getBody(), inputDataBindings, operation.getInputType().getLogical())); + + Message resultMsg = nextInvoker.invoke(msg); + + if (!msg.isFault() && operation.getOutputType() != null) { + resultMsg.setBody(copy(resultMsg.getBody(), outputDataBinding, operation.getOutputType())); + } + + if (msg.isFault()) { + msg.setFaultBody(copyFault(msg.getBody())); + } + return resultMsg; + } + + private Object copyFault(Object fault) { + if (faultExceptionMapper == null) { + return fault; + } + for (DataType et : operation.getFaultTypes()) { + if (et.getPhysical().isInstance(fault)) { + Throwable ex = (Throwable)fault; + DataType<DataType> exType = + new DataTypeImpl<DataType>(ex.getClass(), new DataTypeImpl<XMLType>(ex.getClass(), XMLType.UNKNOWN)); + faultExceptionMapper.introspectFaultDataType(exType, operation, false); + DataType faultType = exType.getLogical(); + Object faultInfo = faultExceptionMapper.getFaultInfo(ex, faultType.getPhysical(), operation); + faultInfo = copy(faultInfo, dataBindings.getDataBinding(faultType.getDataBinding()), faultType); + fault = faultExceptionMapper.wrapFaultInfo(exType, ex.getMessage(), faultInfo, ex.getCause(), operation); + return fault; + } + } + return fault; + } + + /** + * Copy an array of data objects passed to an operation + * @param data array of objects to copy + * @return the copy + */ + private Object[] copy(Object[] data, DataBinding[] dataBindings, List<DataType> dataTypes) { + if (data == null) { + return null; + } + Object[] copy = new Object[data.length]; + Map<Object, Object> map = new IdentityHashMap<Object, Object>(); + for (int i = 0; i < data.length; i++) { + Object arg = data[i]; + if (arg == null) { + copy[i] = null; + } else { + Object copiedArg = map.get(arg); + if (copiedArg != null) { + copy[i] = copiedArg; + } else { + copiedArg = copy(arg, dataBindings[i], dataTypes.get(i)); + map.put(arg, copiedArg); + copy[i] = copiedArg; + } + } + } + return copy; + } + + /** + * Copy data using the specified databinding. + * @param data input data + * @param dataBinding databinding to use + * @param dataType TODO + * @return a copy of the data + */ + private Object copy(Object data, DataBinding dataBinding, DataType dataType) { + if (data == null) { + return null; + } + Class<?> clazz = data.getClass(); + if (String.class == clazz || clazz.isPrimitive() + || Number.class.isAssignableFrom(clazz) + || Boolean.class.isAssignableFrom(clazz) + || Character.class.isAssignableFrom(clazz) + || Byte.class.isAssignableFrom(clazz) + || URI.class == clazz + || UUID.class == clazz + || QName.class == clazz) { + // Immutable classes + return data; + } + // If no databinding was specified, introspect the given arg to + // determine its databinding + if (dataBinding == null) { + dataType = dataBindings.introspectType(data, operation); + if (dataType != null) { + String db = dataType.getDataBinding(); + dataBinding = dataBindings.getDataBinding(db); + if (dataBinding == null && db != null) { + return data; + } + } + if (dataBinding == null) { + + // Default to the JavaBean databinding + dataBinding = javaBeanDataBinding; + } + } + + // Use the JAXB databinding to copy non-Serializable data + if (dataBinding == javaBeanDataBinding) { + + // If the input data is an array containing non Serializable elements + // use JAXB + clazz = data.getClass(); + if (clazz.isArray()) { + if (Array.getLength(data) != 0) { + Object element = Array.get(data, 0); + if (element != null && !(element instanceof Serializable)) { + dataBinding = jaxbDataBinding; + } + } + } else { + + // If the input data is not Serializable use JAXB + if (!(data instanceof Serializable)) { + dataBinding = jaxbDataBinding; + } + + if (data instanceof Cloneable) { + Method clone; + try { + clone = data.getClass().getMethod("clone", (Class[])null); + try { + return clone.invoke(data, (Object[])null); + } catch (InvocationTargetException e) { + if (e.getTargetException() instanceof CloneNotSupportedException) { + // Ignore + } else { + throw new ServiceRuntimeException(e); + } + } catch (Exception e) { + throw new ServiceRuntimeException(e); + } + } catch (NoSuchMethodException e) { + // Ignore it + } + } + } + } + + Object copy = dataBinding.copy(data, dataType, operation); + return copy; + } + + public Invoker getNext() { + return nextInvoker; + } + + public void setNext(Invoker next) { + this.nextInvoker = next; + } + +} |