为什么我的unmarshaller要等到使用XMLStreamReader返回以下start元素后才返回?

I have a Python script and Java test running side-by-side. They both attempt to do the exact same thing - open a socket, receive a never-ending stream of XML, and parse the XML as it is received. The Python script is using Expat, while the Java test is using XMLStreamReader and an Unmarshaller.I have a Python script and Java test running si