关于Excel报错
今天,用POI做一个Excel的导出时,总是报空指针错误。后来经过我仔细的查找翻阅日志才发现问题的真正所在;
报错如下:
HTTP Status 500 - Request processing failed; nested exception is java.lang.NullPointerException
type Exception report
message Request processing failed; nested exception is java.lang.NullPointerException
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 java.lang.NullPointerException org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:973) org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852) javax.servlet.http.HttpServlet.service(HttpServlet.java:624) org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) javax.servlet.http.HttpServlet.service(HttpServlet.java:731) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) com.bool.filter.RequestFilter.doFilterInternal(RequestFilter.java:37) org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108) org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108) com.bool.filter.CorsFilter.doFilter(CorsFilter.java:31)
root cause
java.lang.NullPointerException java.io.ByteArrayInputStream.<init>(ByteArrayInputStream.java:106) com.bool.controller.DetectionController.historyRecordDownkoad(DetectionController.java:264) 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:606) org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215) org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:690) org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83) org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945) org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876) org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961) org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852) javax.servlet.http.HttpServlet.service(HttpServlet.java:624) org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) javax.servlet.http.HttpServlet.service(HttpServlet.java:731) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) com.bool.filter.RequestFilter.doFilterInternal(RequestFilter.java:37) org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108) org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108) com.bool.filter.CorsFilter.doFilter(CorsFilter.java:31)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.77 logs.
但是,这不是问题的所在;当我debug的时候,发现了另一导致出错的原因;
java.lang.IllegalArgumentException: The workbook already contains a sheet with this name
工作簿已经包含一张这个名字;
好了,问题找见了。
解决方案:
修改导出模板中的sheet页名字即可;