Ajith Vitharana's blog: Advance Mediation with WSO2 API Manager(1.9) + WSO2 ESB -3

In this use case WSO2 API Manager act as the gateway, and WSO2 ESB used to execute the mediation logic.

1. This service (http://www.webservicex.com/globalweather.asmx) provides two operations.

GetCitiesByCountry

Get all major cities by country name(full / part).

GetWeather

Get weather report for all major cities around the world.

2. Create an API in ESB to invoke the above operations using following REST operations (ESB start with port offset as 1).

http://localhost:8281/weatheresb/GetCitiesByCountry?CountryName=Romania
http://localhost:8281/weatheresb/GetCitiesByCountry?CountryName=Romania&CityName=Timisoara

Save this file as WeatherAPIESB.xml in <ESB_Home>\repository\deployment\server\synapse-configs\default\api)

<?xml version="1.0" encoding="UTF-8"?>
<api xmlns="http://ws.apache.org/ns/synapse"
     name="WeatherAPIESB"
     context="/weatheresb">
   <resource methods="GET" url-mapping="/GetCitiesByCountry">
      <inSequence>
         <payloadFactory media-type="xml">
            <format>
               <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"
                                 xmlns:web="http://www.webserviceX.NET">
                  <soapenv:Header/>
                  <soapenv:Body>
                     <web:GetCitiesByCountry><web:CountryName>$1</web:CountryName>
                     </web:GetCitiesByCountry>
                  </soapenv:Body>
               </soapenv:Envelope>
            </format>
            <args>
               <arg xmlns:m0="http://services.samples/xsd"
                    evaluator="xml"
                    expression="get-property('query.param.CountryName')"/>
            </args>
         </payloadFactory>
         <send>
            <endpoint>
               <address uri="http://www.webservicex.com/globalweather.asmx" format="soap12"/>
            </endpoint>
         </send>
      </inSequence>
      <outSequence>
         <property name="messageType" value="application/json" scope="axis2"/>
         <send/>
      </outSequence>
   </resource>
   <resource methods="GET" url-mapping="/GetWeather">
      <inSequence>
         <payloadFactory media-type="xml">
            <format>
               <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"
                                 xmlns:web="http://www.webserviceX.NET">
                  <soapenv:Header/>
                  <soapenv:Body>
                     <web:GetWeather><web:CityName>$1</web:CityName>
                        <web:CountryName>$2</web:CountryName>
                     </web:GetWeather>
                  </soapenv:Body>
               </soapenv:Envelope>
            </format>
            <args>
               <arg xmlns:m0="http://services.samples/xsd"
                    evaluator="xml"
                    expression="get-property('query.param.CityName')"/>
               <arg xmlns:m0="http://services.samples/xsd"
                    evaluator="xml"
                    expression="get-property('query.param.CountryName')"/>
            </args>
         </payloadFactory>
         <send>
            <endpoint>
               <address uri="http://www.webservicex.com/globalweather.asmx" format="soap12"/>
            </endpoint>
         </send>
      </inSequence>
      <outSequence>
         <property name="messageType" value="application/json" scope="axis2"/>
         <send/>
      </outSequence>
   </resource>
</api>

3.Create an API in API Manager considering the REST API exposed through the ESB (http://localhost:8281/weatheresb).

4. Design API with two GET resource.