There are situations that we need to
convert xml payloads into JSON. WSO2 ESB provides this support and
refer http://docs.wso2.org/display/ESB481/JSON+Support for more
details.
To convert an XML payload into JSON, we
have to set the messageType property to application/json in synapse
configuration.
Here I discuss about XML to JSON
conversion when multiple attributes and elements available in the
payload.
You may receive a soap request as
follows:
SOAP Request:
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:m0="http://services.samples" xmlns:xsd="http://services.samples/xsd">
<soapenv:Header/>
<soapenv:Body>
<m0:getQuote xmlns:m0="http://services.samples" id="12345">
<person sex="female" fn:target="urn:getQuote" xmlns:fn="abcdef" id="12345">
<firstname>Anna</firstname>
<lastname id="12345678">Smith</lastname>
</person>
<m0:request>
<m0:symbol>A</m0:symbol>
</m0:request>
</m0:getQuote>
</soapenv:Body>
</soapenv:Envelope>
Person element contains multiple
attributes sex, target, namespace and id.
i.e: <person sex="female" fn:target="urn:getQuote" xmlns:fn="abcdef" id="12345">
Also, lastnname is a sub element of
person and it contains attribute as id and text content as "Smith"
i.e: <lastname id="12345678">Smith</lastname>
We will see how to covert such payload
into json and its how the response looks like.
In ESB create a proxy service with
SimpleStockQuote endpoint.
Proxy Service Configuration:
<?xml version="1.0" encoding="UTF-8"?>
<proxy xmlns="http://ws.apache.org/ns/synapse"
name="XMLtoJSON"
transports="https,http"
statistics="disable"
trace="disable"
startOnLoad="true">
<target>
<inSequence>
<property name="messageType" value="application/json" scope="axis2"/>
<log level="full"/>
<respond/>
</inSequence>
<outSequence>
<send/>
</outSequence>
<endpoint>
<address uri="http://localhost:9000/services/SimpleStockQuoteService/"/>
</endpoint>
</target>
<description/>
</proxy>
Note:
For conversion, use "<property
name="messageType" value="application/json"
scope="axis2"/>" in the configuration as discussed
above.
1. You have to start sample backend to
receove response which is provided with WSO2 ESB. (Start axis2Service
@ESB_HOME/samples/axis2Server)
2. Built SimpleStockQuote Service
@ESB_HOME/samples/axis2Server/src/SimpleStockQuoteService by running "ant" command.
3. Send the SOAP request to proxy
service using SOAP UI.
Response should be as follows:
HTTP/1.1 200 OK
Host: shashi-ThinkPad-T530:8280
SOAPAction: "urn:getQuote"
Accept-Encoding: gzip,deflate
Content-Type: application/json
Date: Fri, 24 Jan 2014 06:00:54 GMT
Server: WSO2-PassThrough-HTTP
Transfer-Encoding: chunked
Connection: Keep-Alive
{"getQuote":{"@id":"12345","person":{"@id":"12345","@sex":"female","@target":"urn:getQuote","firstname":"Anna","lastname":{"@id":"12345678","$":"Smith"}},"request":{"symbol":"A"}}}
Points to focus in response:
1. Content-Type should be 'application/json'
2.
XML:
<person sex="female" fn:target="urn:getQuote" xmlns:fn="abcdef" id="12345">
JSON:
"person":{"@id":"12345","@sex":"female","@target":"urn:getQuote"
*** Attributes displayed with prefix '@' in JSON conversion.
("@id":"12345")
When nodes has text content as well as
attributes, that text content is stored in a key with “$”
XML:
<lastname id="12345678">Smith</lastname>
JSON:
"lastname":{"@id":"12345678","$":"Smith"}
If a node has multiple children with
the same tag name, they are converted into a numerically indexed
array e.g. “person”
XML
<person>Anvar</person>
<person>Porter</person>
<person>Raj</person>
JSON
"person":["Anvar","Porter","Raj"]
SOAP request:
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:m0="http://services.samples" xmlns:xsd="http://services.samples/xsd">
<soapenv:Header/>
<soapenv:Body>
<m0:getQuote xmlns:m0="http://services.samples" id="12345">
<person>Anvar</person>
<person>Porter</person>
<person>Raj</person>
<m0:request>
<m0:symbol>A</m0:symbol>
</m0:request>
</m0:getQuote>
</soapenv:Body>
</soapenv:Envelope>
Response:
HTTP/1.1 200 OK
Host: shashi-ThinkPad-T530:8280
SOAPAction: "urn:mediate"
Accept-Encoding: gzip,deflate
Content-Type: application/json
Date: Sun, 09 Feb 2014 02:49:07 GMT
Server: WSO2-PassThrough-HTTP
Transfer-Encoding: chunked
Connection: Keep-Alive
{"getQuote":{"@id":"12345","person":["Anvar","Porter","Raj"],"request":{"symbol":"A"}}}
