在java web应用程序中-使用Jxls导出Excel时出现问题
我无法导出包含查询数据的excel文件。我正在使用java、spring、hibernate和Jxls。 想法很简单，使用按钮导出表中的所有数据。当我点击按钮生成文件时，这是我得到的响应： org.springframework.web.util.NestedServletException:请求处理失败；嵌套异常为java.lang.NullPointerException 我的控制器代码：在java web应用程序中-使用Jxls导出Excel时出现问题,java,spring,hibernate,jxls,Java,Spring,Hibernate,Jxls,我无法导出包含查询数据的excel文件。我正在使用java、spring、hibernate和Jxls。 想法很简单，使用按钮导出表中的所有数据。当我点击按钮生成文件时，这是我得到的响应： org.springframework.web.util.NestedServletException:请求处理失败；嵌套异常为java.lang.NullPointerException 我的控制器代码： /* * To change this license header, choose License
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package Controladores;
import Modelos.HibernateUtil;
import Modelos.Venta;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;
import javax.servlet.http.HttpServletResponse;
import org.hibernate.Session;
import org.jxls.template.SimpleExporter;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
@Controller
@RequestMapping("/reporte.htm")
public class CReporte {
@RequestMapping(method = RequestMethod.GET)
public String metodoGet(HttpServletResponse response) {
return "vReporte";
}
@RequestMapping(method = RequestMethod.POST)
public String exportar(HttpServletResponse response) {
System.out.println("entro en funcion");
List<Venta> venta = obtenerVentas();
System.out.println("obtener ventas: "+ venta);
List<String> headers = Arrays.asList("PRODUCTO Nro", "ID DE TRANSACCION", "MONTO", "FECHA DE VENTA");
System.out.println("headers: "+ headers);
try {
response.addHeader("Content-disposition", "attachment; filename=Ventas.xlsx");
response.setContentType("application/vnd.ms-excel");
new SimpleExporter().gridExport(headers, venta, "idProducto, idVenta,mont,fechaVenta ", response.getOutputStream());
response.flushBuffer();
return "inicio";
} catch (IOException e) {
return "error";
}
}
private List obtenerVentas() {
try {
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction();
List result = session.createQuery("from Venta").list();
session.getTransaction().commit();
session.close();
return result;
} catch (Exception e) {
e.printStackTrace();
System.out.println("aca en exception?");
return null;
}
}
}
/*
*要更改此许可证标题，请在“项目属性”中选择“许可证标题”。
*要更改此模板文件，请选择工具|模板
*然后在编辑器中打开模板。
*/
包装控制崇拜；
导入Modelos.HibernateUtil；
进口Modelos.Venta；
导入java.io.IOException；
导入java.util.array；
导入java.util.List；
导入javax.servlet.http.HttpServletResponse；
导入org.hibernate.Session；
导入org.jxls.template.SimpleExporter；
导入org.springframework.stereotype.Controller；
导入org.springframework.web.bind.annotation.RequestMapping；
导入org.springframework.web.bind.annotation.RequestMethod；
@控制器
@请求映射（“/reporte.htm”）
公共舱室{
@RequestMapping（method=RequestMethod.GET）
公共字符串metodoGet（HttpServletResponse）{
返回“vReporte”；
}
@RequestMapping（method=RequestMethod.POST）
公共字符串导出器（HttpServletResponse）{
System.out.println（“entro en function”）；
List venta=obtenerVentas（）；
系统输出打印项次（“obtener-ventas:+venta”）；
列表头=Arrays.asList（“PRODUCTO Nro”、“ID DE TRANSACCION”、“MONTO”、“FECHA DE VENTA”）；
System.out.println（“标题：“+标题”）；
试一试{
addHeader（“内容处置”、“附件；文件名=Ventas.xlsx”）；
response.setContentType（“application/vnd.ms excel”）；
新的SimpleExporter（）.gridExport（headers，venta，“idProducto，idVenta，mont，fechaVenta”，response.getOutputStream（））；
response.flushBuffer（）；
返回“inicio”；
}捕获（IOE异常）{
返回“错误”；
}
}
私有列表obtenerVentas（）{
试一试{
Session Session=HibernateUtil.getSessionFactory（）.openSession（）；
session.beginTransaction（）；
列表结果=session.createQuery（“来自Venta”）.List（）；
session.getTransaction（）.commit（）；
session.close（）；
返回结果；
}捕获（例外e）{
e、 printStackTrace（）；
System.out.println（“aca-en异常？”）；
返回null；
}
}
}
<%--
Document : vReporte
Created on : 23/02/2020, 13:00:11
Author : jsabate
--%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Reporte</title>
</head>
<body>
<br></br>
<form action="reporte.htm" method="POST">
<br></br>
<br>
<tr>
<td>
<input type="submit" name="generate" value="Generar">
<input type="button" name="back" value="Inicio"onclick="window.location.href='inicio.htm'" />
</td>
</tr>
</br>
</form>
</body>
</html>
报告
Información: HHH000041: Configured SessionFactory: null
WARN: HHH000402: Using Hibernate built-in connection pool (not for production use!)
Información: HHH000401: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://localhost:3306/proyecto_bd]
Información: HHH000046: Connection properties: {user=root}
Información: HHH000006: Autocommit mode: false
Información: HHH000115: Hibernate connection pool size: 20 (min=1)
Información: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect
Información: HHH000399: Using default transaction strategy (direct JDBC transactions)
Información: HHH000397: Using ASTQueryTranslatorFactory
Información: obtener ventas: [Modelos.Venta@8f2c0c, Modelos.Venta@2d497dc0, Modelos.Venta@4db620b7, Modelos.Venta@28b400f6]
Información: headers: [PRODUCTO Nro, ID DE TRANSACCION, MONTO, FECHA DE VENTA]
Grave: 6 [http-listener-1(5)] INFO org.jxls.util.TransformerFactory - Loading transformer by class org.jxls.transform.poi.PoiTransformer
Grave: 113 [http-listener-1(5)] ERROR org.jxls.util.TransformerFactory - Method createTransformer of org.jxls.transform.poi.PoiTransformer class thrown an Exception
Grave: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.jxls.util.TransformerFactory.createTransformer(TransformerFactory.java:43)
at org.jxls.template.SimpleExporter.gridExport(SimpleExporter.java:56)
at Controladores.CReporte.exportar(CReporte.java:42)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:175)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:446)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:434)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:344)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at org.glassfish.tyrus.servlet.TyrusServletFilter.doFilter(TyrusServletFilter.java:305)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:316)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:416)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NoClassDefFoundError: org/apache/commons/math3/util/ArithmeticUtils
at org.apache.poi.poifs.property.RootProperty.setSize(RootProperty.java:59)
at org.apache.poi.poifs.property.DirectoryProperty.<init>(DirectoryProperty.java:52)
at org.apache.poi.poifs.property.RootProperty.<init>(RootProperty.java:31)
at org.apache.poi.poifs.property.PropertyTable.<init>(PropertyTable.java:58)
at org.apache.poi.poifs.filesystem.POIFSFileSystem.<init>(POIFSFileSystem.java:102)
at org.apache.poi.poifs.filesystem.POIFSFileSystem.<init>(POIFSFileSystem.java:274)
at org.apache.poi.ss.usermodel.WorkbookFactory.create(WorkbookFactory.java:252)
at org.apache.poi.ss.usermodel.WorkbookFactory.create(WorkbookFactory.java:221)
at org.jxls.transform.poi.PoiTransformer.createTransformer(PoiTransformer.java:134)
at org.jxls.transform.poi.PoiTransformer.createTransformer(PoiTransformer.java:120)
... 54 more
Caused by: java.lang.ClassNotFoundException: org.apache.commons.math3.util.ArithmeticUtils
at org.glassfish.web.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1783)
at org.glassfish.web.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1633)
... 64 more
Advertencia: StandardWrapperValve[dispatcher]: Servlet.service() for servlet dispatcher threw exception
java.lang.NullPointerException
at org.jxls.builder.xls.XlsCommentAreaBuilder.build(XlsCommentAreaBuilder.java:167)
at org.jxls.template.SimpleExporter.gridExport(SimpleExporter.java:58)
at Controladores.CReporte.exportar(CReporte.java:42)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:175)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:446)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:434)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:344)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at org.glassfish.tyrus.servlet.TyrusServletFilter.doFilter(TyrusServletFilter.java:305)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:316)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:416)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
at java.lang.Thread.run(Thread.java:745)
Información:hh000041:配置的会话工厂：null
警告：HH000402:使用Hibernate内置连接池（不用于生产！）
Información:hh000401：在URL[jdbc:mysql://localhost:3306/proyecto_bd]
Información:hh000046:连接属性：{user=root}
Información:hh000006:自动提交模式：false
Información:HH000115:休眠连接池大小：20（最小值=1）
Información:hh000400:使用方言：org.hibernate.dialogue.mysqldialogue
Información:hh000399：使用默认事务策略（直接JDBC事务）
信息：HH000397：使用ASTQueryTranslatorFactory
信息：obtener ventas:[Modelos。Venta@8f2c0c，Modelos。Venta@2d497dc0，Modelos。Venta@4db620b7，Modelos。Venta@28b400f6]
Información:headers:[PRODUCTO Nro，ID DE TRANSACCION，MONTO，FECHA DE VENTA]
Grave:6[http-listener-1（5）]INFO org.jxls.util.TransformerFactory-按类org.jxls.transform.poi.poitranformer加载转换器
Grave:113[http-listener-1（5）]错误org.jxls.util.TransformerFactory-org.jxls.transform.poi.poitTransformer类的方法CreateTranformer引发异常
Grave:java.lang.reflect.InvocationTargetException
在sun.reflect.NativeMethodAccessorImpl.invoke0（本机方法）处
位于sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:62）
在sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）中
位于java.lang.reflect.Method.invoke（Method.java:498）
位于org.jxls.util.TransformerFactory.createTransformer（TransformerFactory.java:43）
位于org.jxls.template.SimpleExporter.gridExport（SimpleExporter.java:56）
在Controladores.CReporte.exportar（CReporte.java:42）
在sun.reflect.NativeMethodAccessorImpl.invoke0（本机方法）处
位于sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:62）
在sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）中
位于java.lang.reflect.Method.invoke（Method.java:498）
位于org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod（HandlerMethodInvoker.java:175）
位于org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod（AnnotationMethodHandlerAdapter.java:446）
位于org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle（AnnotationMethodHandlerAdapter.java:434）
位于org.springframework.web.servlet.DispatcherServlet.doDispatch（DispatcherServlet.java:945）
位于org.springframework.web.servlet.DispatcherServlet.doService（DispatcherServlet.java:876）
位于org.springframework.web.servlet.FrameworkServlet.processRequest（FrameworkServlet.java:961）
位于org.springframework.web.servlet.FrameworkServlet.doPost（FrameworkServlet.java:863）
位于javax.servlet.http.HttpServlet.service（HttpServlet.java:707）
位于org.springframework.web.servlet.Frame