页面请求数据,后台向页面传输请求到的数据,单独请求没问题。但是如果我请求的过程中另外一个用户请求则我会报异常,而后来的用户可以取到数据。。。。。。
在后台打印数据,数据从库里请求到了。前台页面是用的ajax 但是传输报错 使用的是: String msg= JSONObject.fromObject(r).toString();
response.getWriter().print(msg);
异常:
2017-06-20 15:23:11,825 [http-bio-8081-exec-2] DEBUG [org.springframework.web.servlet.DispatcherServlet] - Could not complete request
java.lang.NullPointerException
at org.apache.coyote.http11.InternalOutputBuffer.realWriteBytes(InternalOutputBuffer.java:215)
at org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:480)
at org.apache.tomcat.util.buf.ByteChunk.append(ByteChunk.java:366)
at org.apache.coyote.http11.InternalOutputBuffer$OutputStreamOutputBuffer.doWrite(InternalOutputBuffer.java:240)
at org.apache.coyote.http11.filters.IdentityOutputFilter.doWrite(IdentityOutputFilter.java:93)
at org.apache.coyote.http11.AbstractOutputBuffer.doWrite(AbstractOutputBuffer.java:192)
at org.apache.coyote.Response.doWrite(Response.java:499)
at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:402)
at org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:480)
at org.apache.catalina.connector.OutputBuffer.realWriteChars(OutputBuffer.java:485)
at org.apache.tomcat.util.buf.CharChunk.flushBuffer(CharChunk.java:464)
at org.apache.tomcat.util.buf.CharChunk.append(CharChunk.java:384)
at org.apache.catalina.connector.OutputBuffer.write(OutputBuffer.java:548)
at org.apache.catalina.connector.CoyoteWriter.write(CoyoteWriter.java:174)
at org.apache.catalina.connector.CoyoteWriter.write(CoyoteWriter.java:184)
at org.apache.catalina.connector.CoyoteWriter.print(CoyoteWriter.java:242)
at com.ruifight.custom.controller.ScreenController.indoor(ScreenController.java:155)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:178)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:442)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:430)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:85)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)