Content-Length incorrect when initializing body with this.class.getResourceAsStream

[BowenHuang80]

InputStream reqBody = RestAssuredTest.class.getResourceAsStream("requestbody.xml");

	given()
	.request()
	.body(reqBody)
	.baseUri("http://scooterlabs.com/echo")
	.header("Host", "scooterlabs.com")
	.header("Content-Type", "text/xml; charset=\"UTF-8\"")
	.header("Accept-Encoding", "gzip,deflate")
	.header("Accept", "*/*")
	.post()
	.print();

The echoed request shows the size is incorrect.

Here is the file requestbody.xml
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:tem="http://tempuri.org/">
soapenv:Header/
soapenv:Body
tem:Add
tem:intA100</tem:intA>
tem:intB356</tem:intB>
</tem:Add>
</soapenv:Body>
</soapenv:Envelope>