Get "^M" but "\n" when transfer Return Character from XML format to JSON format in wso2esb - json

Question

I got the problem as title said when transferring Return Character from XML format to JSON format in wso2esb.
In ML format, the string is "1234
123", and when using the following code to transfer,
<payloadFactory media-type="json">
<format>
$1
</format>
<args>
<arg evaluator="json" expression="$.text"/>
</args>
</payloadFactory>
<property name="messageType" scope="axis2" type="STRING" value="application/json"/>
I got the result of "1234^M123". But in fact, it should be '\n', otherwise, the next Java application cannot wrapper the json message to object.(Exception: Illegal unquoted character ((CTRL-CHAR, code 13)): has to be escaped using backslash to be included in string value).
Here's the payload info just before "payloadFactory" as follows, and mentioned problem occurred for "comment" field:
INFO {org.apache.synapse.mediators.builtin.LogMediator} - To: , From: mailto:mail#dev.dev, WSAction: urn:mediate, SOAPAction: urn:mediate, MessageID: <1709772976.1.1481784107877#localhost>, Direction: request, Envelope: <?xml version='1.0' encoding='utf-8'?><soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><soapenv:Body><text xmlns="http://ws.apache.org/commons/ns/payload">{"source":"test", "refNo":"202591", "comments":"1234
123" }
</text></soapenv:Body></soapenv:Envelope>
Could anybody help to the problem please?