/*
* 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.filters;
import org.apache.synapse.ManagedLifecycle;
import org.apache.synapse.MessageContext;
import org.apache.synapse.SynapseLog;
import org.apache.synapse.config.xml.SwitchCase;
import org.apache.synapse.core.SynapseEnvironment;
import org.apache.synapse.mediators.AbstractMediator;
import org.apache.synapse.util.xpath.SynapseXPath;
import java.util.ArrayList;
import java.util.List;
/**
* The switch mediator implements the functionality of the "switch" construct. It first
* evaluates the given XPath expression into a String value, and performs a match against
* the given list of cases. This is actually a list of sequences, and depending on the
* selected case, the selected sequence gets executed.
*/
public class SwitchMediator extends AbstractMediator implements ManagedLifecycle {
/** The XPath expression specifying the source element to apply the switch case expressions against */
private SynapseXPath source = null;
/** The list of switch cases */
private final List<SwitchCase> cases = new ArrayList<SwitchCase>();
/** The default switch case, if any */
private SwitchCase defaultCase = null;
public void init(SynapseEnvironment se) {
for (ManagedLifecycle swCase : cases) {
swCase.init(se);
}
if (defaultCase != null) {
defaultCase.init(se);
}
}
public void destroy() {
for (ManagedLifecycle swCase : cases) {
swCase.destroy();
}
if (defaultCase != null) {
defaultCase.destroy();
}
}
/**
* Iterate over switch cases and find match and execute selected sequence
*
* @param synCtx current context
* @return as per standard semantics
*/
public boolean mediate(MessageContext synCtx) {
SynapseLog synLog = getLog(synCtx);
if (synLog.isTraceOrDebugEnabled()) {
synLog.traceOrDebug("Start : Switch mediator");
if (synLog.isTraceTraceEnabled()) {
synLog.traceTrace("Message : " + synCtx.getEnvelope());
}
}
int parentsEffectiveTraceState = synCtx.getTracingState();
// if I have been explicitly asked to enable or disable tracing, set it to the message
// to pass it on; else, do nothing -> i.e. let the parents state flow
setEffectiveTraceState(synCtx);
String sourceText = source.stringValueOf(synCtx);
if (synLog.isTraceOrDebugEnabled()) {
synLog.traceOrDebug("XPath : " + source + " evaluates to : " + sourceText);
}
try {
if ((sourceText == null || cases.isEmpty()) && defaultCase != null) {
synLog.traceOrDebug("Source XPath evaluated to : null or no switch " +
"cases found. Executing the default case");
return defaultCase.mediate(synCtx);
} else {
for (SwitchCase swCase : cases) {
if (swCase != null) {
if (swCase.matches(sourceText)) {
if (synLog.isTraceOrDebugEnabled()) {
synLog.traceOrDebug("Matching case found : " + swCase.getRegex());
}
return swCase.mediate(synCtx);
}
}
}
if (defaultCase != null) {
// if any of the switch cases did not match
synLog.traceOrDebug("None of the switch cases matched - executing default");
return defaultCase.mediate(synCtx);
} else {
synLog.traceOrDebug("None of the switch cases matched - no default case");
}
}
} finally {
synCtx.setTracingState(parentsEffectiveTraceState);
}
synLog.traceOrDebug("End : Switch mediator");
return true;
}
/**
* Adds the given mediator (Should be a SwitchCaseMediator) to the list of cases
* of this Switch mediator
*
* @param m the SwitchCaseMediator instance to be added
*/
public void addCase(SwitchCase m) {
cases.add(m);
}
/**
* Get the list of cases
*
* @return the cases list
*/
public List<SwitchCase> getCases() {
return cases;
}
/**
* Return the source XPath expression set
*
* @return thje source XPath expression
*/
public SynapseXPath getSource() {
return source;
}
/**
* Sets the source XPath expression
*
* @param source the XPath expression to be used as the source
*/
public void setSource(SynapseXPath source) {
this.source = source;
}
/**
* Get default case
*
* @return the default csae
*/
public SwitchCase getDefaultCase() {
return defaultCase;
}
/**
* setting the default case ...which contains mediators to invoke when no case condition satisfy
* @param defaultCase A SwitchCase instance representing default case
*/
public void setDefaultCase(SwitchCase defaultCase) {
this.defaultCase = defaultCase;
}
}