Mule2.x - expression-recipient-list-router – Dynamic Endpoint in mule

Mule2.x - expression-recipient-list-router – Dynamic Endpoint in mule

The expression recipient list router can be used to send the same message to multiple endpoints over the same endpoint or to implement routing-slip behavior where the next destination for the message is determined from message properties or the payload. It uses a list of recipient’s endpoints which are extracted from the message using an expression.

Here I will give you an example how to use the expression-recipient-list-router.

In this example I am using mule 2.2. (http://www.mulesource.org)


Mule-config.xml

Spring declaration
<spring:bean id="ExpressionHandlerBean"
class="com.javatch.expression.ExpressionHandlerBean">

actual mule configuration
<model name="test Expression">
<service name="Expression">
<inbound>
<vm:inbound-endpoint address="vm://Expression" synchronous="true" >
</vm:inbound-endpoint>
</inbound>
<component>
<spring-object bean="ExpressionHandlerBean"></spring-object>
</component>
<outbound>
<expression-recipient-list-router evaluator="header"
expression="ADDR_LIST" >
</expression-recipient-list-router>
</outbound>
</service>

<service name="TEST">
<inbound>
<vm:inbound-endpoint address="vm://TEST" synchronous="true" />
</inbound>
<outbound>
<pass-through-router>
<file:outbound-endpoint path="${some temp dir}"
transformer-refs="ValidateTheFlow" />
</pass-through-router>
</outbound>
</service>
</model>





In the component class I am adding the endpoint, here if you can any number endpoint ExpressionRecipientList.java (from Mule) will take care of functional flow. 

ExpressionHandlerBean.java

public class ExpressionHandlerBean implements Callable {

public Object onCall(MuleEventContext eventContext) throws Exception {
try {
List<String> addressList = new ArrayList<String>();
addressList.add("vm://TEST");
eventContext.getMessage().setProperty("ADDR_LIST",addressList);
}
catch( Exception ex ) {
ex.printStackTrace();
}
return null;
}

}

Setting up EhCache using Spring

Setting up EhCache using Spring

Ehcache is a pure Java cache with the following features: fast, simple, small foot print, minimal dependencies, provides memory and disk stores for scalability into gigabytes, scalable to hundreds of caches are a pluggable cache for Hibernate.

Here I am going to explain how to integrate ehcache with spring.

Following jar files are required in the class path in order to run this application J
ehcache-1.6.0-beta3.jar
spring-2.5.5.jar

We use ehcache.xml to configure all cache related information.


<ehcache>
<diskStore path="java.io.tmpdir"/>
<cache name="javatchEhcache"
maxElementsInMemory="1000"
eternal="true"
overflowToDisk="false"/>
<defaultCache
maxElementsInMemory="200"
maxElementsOnDisk="500"
eternal="false"
timeToIdleSeconds="120"
timeToLiveSeconds="120"
overflowToDisk="true"/>
</ehcache>

Back to spring configuration, we have to configure ehcache dependencies in to spring.

beans.xml:

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd">

<bean id="ecManager" class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean">
<property name="configLocation" value="classpath:ehcache.xml" />
</bean>

<bean id="mycache" class=" com.javatch.ehcache.example.EhCacheManager" init-method="setupCache">
<property name="cacheManager" ref="ecManager"/>
</bean>

</beans>

Create ehcache reference from java
EhCacheManager.java
package com.javatch.ehcache.example;

import net.sf.ehcache.Cache;
import net.sf.ehcache.CacheManager;
import net.sf.ehcache.Element;

import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.FileSystemResource;

public class EhCacheManager {

private CacheManager cacheManager;
private static Cache myCache = null;

public void setCacheManager(CacheManager cacheManager) {
this.cacheManager = cacheManager;
}

private void setupCache() {
String cacheName = "javatchEhcache";
System.out.println("cache Name [" + cacheName + "]");
myCache = cacheManager.getCache(cacheName);
}

private static Element getValues(String key){
Element value = myCache.get(key);
if(value!=null) {
System.out.println("from cache");
return value;
} else {
// DAO call goes here...
myCache.put(new Element(key, "Object"));
System.out.println("not from cache");
}
return value;
}
private static void setValuesIntoCache(){
myCache.put(new Element("OS", "OSCache"));
myCache.put(new Element("OD", "OracleDBCache"));
}
public static void main(String[] args) {

BeanFactory factory = new XmlBeanFactory(new FileSystemResource("beans.xml"));
System.out.println(factory.getBean("mycache"));
setValuesIntoCache();
getValues("NB");

}

}

Thank you 