The big thing you get with asynchronous servlets is HTTP push, where the server can fire information back to the client when it chooses to, rather than when the client asks for it. Pre-asynch servlets, this would require long-running HTTP connections which each tied up a server thread, which is very inefficient. This new model decouples the server-side processing from the connection handling.
与恶龙缠斗过久,自身亦成为恶龙；凝视深渊过久,深渊将回以凝视…
