This documentation is for WSO2 Enterprise Integrator version 6.0.0 . View documentation for the latest release in the 6.x.x family and the latest release in the 7.x.x family.

All docs This doc
Skip to end of metadata
Go to start of metadata

The Class Mediator creates an instance of a custom-specified class and sets it as a mediator. The class must implement the org.apache.synapse.api.Mediator interface. If any properties are specified, the corresponding setter methods are invoked once on the class during initialization.

The Class mediator is a custom Java class, which you need to maintain by yourself. Therefore, it is recommended to use the Class mediator only for not frequently re-used custom developments and very user-specific scenarios, for which, there is no built-in mediator that already provides the required functionality. 

Your class mediator might not be picked up and updated, if you use an existing package when creating it.

For best results, use WSO2 Developer Studio for debugging Class mediators.


<class name="class-name">
   <property name="string" value="literal">

UI Configuration

Class Name: The name of the class. To load a class, enter the qualified name of the relevant class in this parameter and click Load Class


You can configure the mediator using XML. Click switch to source view in the Mediator window.


In this configuration, the EI sends the requested message to the endpoint  specified via the Send mediator . This endpoint is the Axis2server running on port 9000. The response message is passed through a Class mediator before it is sent back to the client. Two parameters named  variable1  and  variable2  are passed to the instance mediator implementation class ( SimpleClassMediator ).

<definitions xmlns="">

        <sequence name="fault">
                <code value="tns:Receiver" xmlns:tns=""/>
                <reason value="Mediation failed."/>

        <sequence name="main" onError="fault">
                    <endpoint name="stockquote">
                        <address uri="http://localhost:9000/services/SimpleStockQuoteService"/>
                <class name="samples.mediators.SimpleClassMediator">
                    <property name="variable1" value="10"/>
                    <property name="variable2" value="5"/>


See the following sample Class Mediator and note the SynapseMessageContext and the full Synapse API in there.

package samples.mediators;

    import org.apache.synapse.MessageContext;
    import org.apache.synapse.mediators.AbstractMediator;
    import org.apache.axiom.soap.SOAPFactory;
    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;

    import javax.xml.namespace.QName;

    public class SimpleClassMediator extends AbstractMediator {

        private static final Log log = LogFactory.getLog(SimpleClassMediator.class);

        private String variable1="10";

        private String variable2="10";

        private int variable3=0;

        public SimpleClassMediator(){}

        public boolean mediate(MessageContext mc) {
            // Do somthing useful..
            // Note the access to the Synapse Message context
            return true;

        public String getType() {
            return null;

        public void setTraceState(int traceState) {
            traceState = 0;

        public int getTraceState() {
            return 0;

        public void setVariable1(String newValue) {

        public String getVariable1() {
            return variable1;

        public void setVariable2(String newValue){

        public String getVariable2(){
            return variable2;


For more examples, see:

  • No labels