是哦的ajax请求，偶尔会出现的问题
后台架构：spring mvc 3.13
服务器 tomcat 6.0.36
HTTP Status 500 - Request processing failed; nested exception is org.apache.tomcat.jni.Error: 620015: APR does not understand this error code
type Exception report
message Request processing failed; nested exception is org.apache.tomcat.jni.Error: 620015: APR does not understand this error code
description The server encountered an internal error that prevented it from fulfilling this request.
exception
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.apache.tomcat.jni.Error: 620015: APR does not understand this error code
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:894)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:789)
javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
root cause
org.apache.tomcat.jni.Error: 620015: APR does not understand this error code
org.apache.tomcat.jni.Socket.sendbb(Native Method)
org.apache.coyote.http11.InternalAprOutputBuffer.flushBuffer(InternalAprOutputBuffer.java:711)
org.apache.coyote.http11.InternalAprOutputBuffer$SocketOutputBuffer.doWrite(InternalAprOutputBuffer.java:742)
org.apache.coyote.http11.filters.ChunkedOutputFilter.doWrite(ChunkedOutputFilter.java:126)
org.apache.coyote.http11.InternalAprOutputBuffer.doWrite(InternalAprOutputBuffer.java:552)
org.apache.coyote.Response.doWrite(Response.java:560)
org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:364)
org.apache.tomcat.util.buf.ByteChunk.append(ByteChunk.java:339)
org.apache.tomcat.util.buf.IntermediateOutputStream.write(C2BConverter.java:242)
sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:221)
sun.nio.cs.StreamEncoder.implWrite(StreamEncoder.java:282)
sun.nio.cs.StreamEncoder.write(StreamEncoder.java:125)
sun.nio.cs.StreamEncoder.write(StreamEncoder.java:135)
java.io.OutputStreamWriter.write(OutputStreamWriter.java:220)
org.apache.tomcat.util.buf.C2BConverter.convert(C2BConverter.java:87)
org.apache.catalina.connector.OutputBuffer.write(OutputBuffer.java:468)
org.apache.catalina.connector.CoyoteWriter.write(CoyoteWriter.java:162)
org.apache.catalina.connector.CoyoteWriter.write(CoyoteWriter.java:171)
com.tlearning.elearningweb.spring.WebOutput.print(WebOutput.java:269)
com.tlearning.elearningweb.spring.WebOutput.toJson(WebOutput.java:290)
com.tlearning.elearningweb.spring.ControllerHelper.ajaxControllerQuery(ControllerHelper.java:29)
com.tlearning.elearningweb.web.traincenter.TrainCenterController.findChildren(TrainCenterController.java:64)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:601)
org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:219)
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:100)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:604)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:565)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:923)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:789)
javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.36 logs.
