/*
* 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.synapse.mediators.base;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.synapse.Constants;
import org.apache.synapse.Mediator;
import org.apache.synapse.MessageContext;
import org.apache.synapse.SynapseException;
import org.apache.synapse.core.axis2.Axis2MessageContext;
import org.apache.synapse.mediators.AbstractListMediator;
/**
* The Sequence mediator either refers to a named Sequence mediator instance
* or is a *Named* list/sequence of other (child) Mediators
* <p/>
* If this instance defines a sequence mediator, then the name is required, and
* an errorHandler sequence name optional. If this instance refers to another (defined)
* sequence mediator, the errorHandler will not have a meaning, and if an error in
* encountered in the reffered sequence, its errorHandler would execute.
*/
public class SequenceMediator extends AbstractListMediator {
private static final Log log = LogFactory.getLog(SequenceMediator.class);
private static final Log trace = LogFactory.getLog(Constants.TRACE_LOGGER);
private String name = null;
private String ref = null;
private String errorHandler = null;
/**
* If this mediator refers to another named Sequence, execute that. Else
* execute the list of mediators (children) contained within this. If a referenced
* named sequence mediator instance cannot be found at runtime, an exception is
* thrown. This may occur due to invalid configuration of an erroneous runtime
* change of the synapse configuration. It is the responsibility of the
* SynapseConfiguration builder to ensure that dead references are not present.
*
* @param synCtx the synapse message
* @return as per standard mediator result
*/
public boolean mediate(MessageContext synCtx) {
log.debug("Sequence mediator <" + (name == null ? "anonymous" : name) + "> :: mediate()");
boolean shouldTrace = shouldTrace(synCtx.getTracingState());
if (ref == null) {
try {
if (shouldTrace) {
trace.trace("Start : Sequence <" + (name == null ? "anonymous" : name) + ">");
}
return super.mediate(synCtx);
} catch (SynapseException e) {
if (errorHandler != null) {
if (shouldTrace) {
trace.trace("Sequence " + name + " encountered an exception. " +
"Locating error handler sequence : " + errorHandler);
}
// set exception information to message context
Axis2MessageContext.setErrorInformation(synCtx, e);
Mediator errHandler = synCtx.getConfiguration().getNamedSequence(errorHandler);
if (errHandler == null) {
if (shouldTrace) {
trace.trace("Sequence " + name + "; error handler sequence named '" +
errorHandler + "' not found");
}
handleException("Error handler sequence mediator instance named " +
errorHandler + " cannot be found");
} else {
if (shouldTrace) {
trace.trace("Sequence " + name + "; Executing error handler sequence : "
+ errorHandler);
}
return errHandler.mediate(synCtx);
}
} else {
if (shouldTrace) {
trace.trace("Sequence " + name + " encountered an exception, but does " +
"not specify an error handler");
}
throw e;
}
} finally {
if (shouldTrace) {
trace.trace("End : Sequence <" + (name == null ? "anonymous" : name) + ">");
}
}
} else {
Mediator m = synCtx.getConfiguration().getNamedSequence(ref);
if (m == null) {
if (shouldTrace) {
trace.trace("Sequence named " + ref + " cannot be found.");
}
handleException("Sequence named " + ref + " cannot be found.");
} else {
if (shouldTrace) {
trace.trace("Executing sequence named " + ref);
}
return m.mediate(synCtx);
}
}
return false;
}
private void handleException(String msg) {
log.error(msg);
throw new SynapseException(msg);
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getRef() {
return ref;
}
public void setRef(String ref) {
this.ref = ref;
}
public String getErrorHandler() {
return errorHandler;
}
public void setErrorHandler(String errorHandler) {
this.errorHandler = errorHandler;
}
}