为啥我的总是报这种错

信息: Server startup in 1693 ms

start....AsynFilter.

二月 17, 2017 4:41:36 下午 org.apache.catalina.core.StandardWrapperValve invoke

严重: Servlet.service() for servlet [AsynServlet] in context with path [/Filter] threw exception

java.lang.IllegalStateException: Not supported.

at org.apache.catalina.connector.Request.startAsync(Request.java:1676)

at org.apache.catalina.connector.Request.startAsync(Request.java:1669)

at org.apache.catalina.connector.RequestFacade.startAsync(RequestFacade.java:1024)

at com.servlet.AsynServlet.doGet(AsynServlet.java:19)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)

at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)

at com.filter3.AsynFilter.doFilter(AsynFilter.java:26)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)

at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)

at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)

at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)

at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)

at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)

at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)

at java.lang.Thread.run(Unknown Source)

servlet开始时间：Fri Feb 17 16:41:36 CST 2017