/*
* 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.transform.url;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.synapse.commons.evaluators.Evaluator;
import org.apache.synapse.commons.evaluators.EvaluatorContext;
import org.apache.synapse.commons.evaluators.EvaluatorException;
import org.apache.synapse.MessageContext;
import org.apache.synapse.core.axis2.Axis2MessageContext;
import java.util.List;
import java.util.ArrayList;
import java.util.Map;
import java.util.HashMap;
import java.net.URISyntaxException;
/**
* Represents a URL rewrite rule. A rule can consist of an optional condition
* and one or more rewrite actions. If the condition is present, actions will be
* executed only when the condition evaluates to true. If the condition is not
* present, all the provided actions will be executed. If an error occurs while
* evaluating the condition, the condition is treated as evaluated to false.
* Condition evaluation is handled by Synapse evaluator framework. When executing
* multiple rewrite actions, they are executed in the specified order.
*/
public class RewriteRule {
private static final Log log = LogFactory.getLog(RewriteRule.class);
private Evaluator condition;
private List<RewriteAction> actions = new ArrayList<RewriteAction>();
public void rewrite(URIFragments fragments,
MessageContext messageContext) throws URISyntaxException {
if (condition != null) {
String uriString = fragments.toURIString();
Map<String, String> headers = getHeaders(messageContext);
EvaluatorContext ctx = new EvaluatorContext(uriString, headers);
ctx.setProperties(((Axis2MessageContext) messageContext).getProperties());
ctx.setMessageContext(((Axis2MessageContext) messageContext).getAxis2MessageContext());
if (log.isTraceEnabled()) {
log.trace("Evaluating condition with URI: " + uriString);
}
try {
if (!condition.evaluate(ctx)) {
if (log.isTraceEnabled()) {
log.trace("Condition evaluated to 'false' - Skipping the current action");
}
return;
}
if (log.isTraceEnabled()) {
log.trace("Condition evaluated to 'true' - Performing the stated action");
}
} catch (EvaluatorException e) {
log.warn("Error while evaluating the condition - Skipping the rule as it failed", e);
return;
}
}
for (RewriteAction action : actions) {
action.execute(fragments, messageContext);
}
}
private Map<String, String> getHeaders(MessageContext synCtx) {
Axis2MessageContext axis2smc = (Axis2MessageContext) synCtx;
org.apache.axis2.context.MessageContext axis2MessageCtx =
axis2smc.getAxis2MessageContext();
Object headers = axis2MessageCtx.getProperty(
org.apache.axis2.context.MessageContext.TRANSPORT_HEADERS);
Map<String, String> evaluatorHeaders = new HashMap<String, String>();
if (headers != null && headers instanceof Map) {
Map headersMap = (Map) headers;
for (Object entryObj : headersMap.entrySet()) {
Map.Entry entry = (Map.Entry) entryObj;
if (entry.getKey() instanceof String && entry.getValue() instanceof String) {
evaluatorHeaders.put((String) entry.getKey(), (String) entry.getValue());
}
}
}
return evaluatorHeaders;
}
public Evaluator getCondition() {
return condition;
}
public void setCondition(Evaluator condition) {
this.condition = condition;
}
public void addRewriteAction(RewriteAction action) {
actions.add(action);
}
public List<RewriteAction> getActions() {
return actions;
}
}