Question

我想生成一个excel文件：

...
<a href="<c:url value='/exportExcel' />">Export</a>
...

// inside controller :
@RequestMapping(value = "/exportExcel", method = RequestMethod.GET)
public ModelAndView exportExcel(HttpServletRequest request) {
    return new ModelAndView("excelExport");
}

servlet-context.xml ：

<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/mvc"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:beans="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->

    <!-- Enables the Spring MVC @Controller programming model -->
    <annotation-driven />

    <!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->
    <resources mapping="/resources/**" location="/resources/" />

    <beans:bean id="viewResolver1" class="org.springframework.web.servlet.view.XmlViewResolver">
        <beans:property name="order" value="1"/>
        <beans:property name="location" value="/WEB-INF/views.xml"/>
    </beans:bean>

    <!-- Resolves views selected for rendering by @Controllers to .jsp resources in the /WEB-INF/views directory -->
    <beans:bean id="viewResolver2"
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <beans:property name="order" value="2"/>
        <beans:property name="prefix" value="/WEB-INF/views/" />
        <beans:property name="suffix" value=".jsp" />
    </beans:bean>

    <beans:bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> 
        <beans:property name="maxUploadSize" value="300000000"/>
    </beans:bean>

    <context:component-scan base-package="com.ambre.pta" />

</beans:beans>

views.xml ：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

    <bean id="excelExport" class="com.ambre.pta.view.ExcelExportView" />

</beans>

ExcelExportView类：

public class ExcelExportView extends AbstractXlsxView {

    @Autowired
    private ExportationDAO exportationDao;

    @Override
    protected void buildExcelDocument(Map<String, Object> model, Workbook workbook, HttpServletRequest request, HttpServletResponse response) throws Exception {

        response.setHeader("Content-Disposition", "attachment; filename=\"export.xlsx\"");

        for(Object[] param : exportationDao.getAllParams()) {

            Sheet sheet = workbook.createSheet(String.valueOf(param[1]));
            Row header = sheet.createRow(0);
            List<DetailsParamExport> entetes = exportationDao.getAllDetailsParams(Integer.parseInt(String.valueOf(param[0])));
            int enteteIdx = 0;
            for (DetailsParamExport detail : entetes) {
                header.createCell(enteteIdx).setCellValue(detail.getEntete());
                enteteIdx++;
            }
            List<Object[]> rows = exportationDao.getSqlResults(String.valueOf(param[3]));
            int rowIdx = 1;
            for (Object[] row : rows) {
                Row excelRow = sheet.createRow(rowIdx++);
                for (int p=0; p<enteteIdx; p++) {
                    excelRow.createCell(p).setCellValue("cccccccc");
                }
            }

        }

    }

}

在运行时单击“导出”链接，然后我得到空白页面，并且不会出现下载框。那有什么不对？

Answer 1

你正在注入一个Spring bean

enum DAY           
{

sunday = 0,    
monday,     
tuesday,  
wednesday,      ****/* wednesday is associated with 3 as Sunday is 0*/****  
thursday,  
friday  

} workday;

在Spring类的非托管内部@Autowired private ExportationDAO exportationDao;。所以当你调用ExcelExportView时，你可能会得到一个空指针异常。你检查了你的日志吗？

您可以将exportationDao.getAllParams()数组从控制器传递到params，并且不要在view

中使用exportationDao

您的控制器：

ExcelExportView

您的ExcelExportView：

@Autowired
private ExportationDAO exportationDao;

@RequestMapping(value = "/exportExcel", method = RequestMethod.GET)
public ModelAndView exportExcel(HttpServletRequest request) {
    ModelAndView mv = new ModelAndView("excelExport");
    modelAndView.addObject("params", exportationDao.getAllParams());
    return mv; 
}

下载无法启动

1 个答案: