用于excel视图解析器的spring Java配置

Question

我有一个带有 (jsp) 视图解析器的基于 Spring Java 配置的 Web 应用程序。 现在，当用户单击应用程序中的 excel 图标时，我想显示一个包含一些数据的 excel 表。 在整个互联网上，我只找到了我不熟悉的 excel 视图的基于 xml 的 spring 配置。 我在某种程度上进行了解码，并且非常接近完成我的任务。以下是我得到的。

我有类似的控制器和主页点击以下链接：

http://static.springsource.org/spring/docs/3.0.0.M3/reference/html/ch17s06.html

控制代码：

@Controller
public class ExcelController extends AbstractController {

@Override
@RequestMapping(value = "/Excel", method = RequestMethod.POST)
protected ModelAndView handleRequestInternal(HttpServletRequest request,
        HttpServletResponse response) throws Exception {
    BufferedReader in = null;
     try {
            URL oracle = new URL("example.com");
            URLConnection yc =null;
                yc = oracle.openConnection();
                  in = new BufferedReader(
                         new InputStreamReader(
                         yc.getInputStream()));
     }
     catch(Exception e){
         System.err.println(e);
     }
     Map map = new HashMap();
     map.put("input", in);

    return new ModelAndView("xl", map);
}

}

查看代码：

public class ExcelReportView extends AbstractExcelView{

@Override
protected void buildExcelDocument(Map model, HSSFWorkbook workbook,
    HttpServletRequest request, HttpServletResponse response)
    throws Exception {
        HSSFSheet sheet;
        HSSFRow row;
        HSSFCell cell;
     try {
            BufferedReader in = (BufferedReader) model.get("input");            
            sheet=workbook.createSheet("spring");

                     String inputLine;
                     int rowNum =0;
                        while ((inputLine = in.readLine()) != null) {
                             row = sheet.createRow(rowNum++);
                            String[] coloumns = inputLine.split("\t");
                            int cellNum =0;
                            for(String coloumn: coloumns){
                                    cell = row.createCell(cellNum++);
                                   cell.setCellValue(coloumn);
                            }
                            System.out.println(inputLine);
                } 
                        in.close();  
                        System.out.println("Excel written successfully..");

                } catch (IOException e) {
                    e.printStackTrace();
                }

} }

view.properties

 xl.class=package.ExcelReportView   

WebAppConfig.java

@Configuration
@EnableWebMvc
@ComponentScan(basePackages = "package")
public class WebAppContextConfig extends WebMvcConfigurerAdapter {
// Resolve logical view names to .jsp resources in /WEB-INF/views directory

@Bean
public InternalResourceViewResolver configureInternalResourceViewResolver() {
    InternalResourceViewResolver resolver = new InternalResourceViewResolver();
    resolver.setPrefix("/WEB-INF/jsp/");
    resolver.setSuffix(".jsp");
    return resolver;
}

@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
    registry.addResourceHandler("/scripts/**").addResourceLocations(
            "/scripts/");
    registry.addResourceHandler("/css/**").addResourceLocations("/css/");
    registry.addResourceHandler("/img/**").addResourceLocations("/img/");
}

}

前端代码：

 function AjaxCallForExcel(){
   $.ajax({
        type: 'POST',
        url: location.href + '/Excel',
        data: ({name:name })
        }); 
   }

以下是我在日志中看到的内容：

 DispatcherServlet with name 'appServlet' processing POST request for [/App/Excel]
 Looking up handler method for path /App/Excel
 Returning handler method [protected org.springframework.web.servlet.ModelAndView package.ExcelController.handleRequestInternal(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse) throws java.lang.Exception]
 Returning cached instance of singleton bean 'excelController'
 Invoking afterPropertiesSet() on bean with name 'xl'
 Rendering view [org.springframework.web.servlet.view.JstlView: name 'xl'; URL [**/WEB-INF/jsp/xl.jsp**]] in DispatcherServlet with name 'appServlet'
 Added model object 'org.springframework.validation.BindingResult.input' of type [org.springframework.validation.BeanPropertyBindingResult] to request in view with name 'xl'
 Added model object 'input' of type [java.io.BufferedReader] to request in view with name 'xl'
 Forwarding to resource [/WEB-INF/jsp/xl.jsp] in InternalResourceView 'xl'
 Successfully completed request

我不知道如何避免它转发到 xl.jsp。我确信视图解析器正在将其放入 jsp 视图中。有人可以指出我该如何解决它。

编辑

我在网上看到了这个 xml 等效配置。不知道如何使它成为java config：

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

我尝试用以下方式转换它：

@Bean
public XmlViewResolver configureXmlViewResolver(){
    XmlViewResolver resolver = new XmlViewResolver();
    resolver.setOrder(1);
    resolver.setLocation(**WHAT SHOULD BE HERE**);
}

我不知道该放什么位置。我不能给字符串。我没有views.xml，因为我使用的是java configs

编辑（这是我按照您所说的进行更改后的代码）

public class ExcelReportView extends AbstractExcelView{
BufferedReader in;
ExcelReportView(BufferedReader in){
this.in = in;
 }

@Override
protected void buildExcelDocument(Map model, HSSFWorkbook workbook,
    HttpServletRequest request, HttpServletResponse response)
    throws Exception {
        HSSFSheet sheet;
        HSSFRow row;
        HSSFCell cell;
        response.setHeader("Content-Type", "application/octet-stream");
        response.setHeader("Content-Disposition", "attachment; filename=MyExcelSpreadsheet.xls");

     try {
            //BufferedReader in = (BufferedReader) model.get("input");          
            sheet=workbook.createSheet("spring");

                     String inputLine;
                     int rowNum =0;
                        while ((inputLine = in.readLine()) != null) {
                             row = sheet.createRow(rowNum++);
                            String[] coloumns = inputLine.split("\t");
                            int cellNum =0;
                            for(String coloumn: coloumns){
                                    cell = row.createCell(cellNum++);
                                   cell.setCellValue(coloumn);
                            }
                            System.out.println(inputLine);
                } 
                        in.close();  
                        System.out.println("Excel written successfully..");

                } catch (IOException e) {
                    e.printStackTrace();
                }
     OutputStream outStream = null;

        try {
            outStream = response.getOutputStream();
            workbook.write(outStream);
            outStream.flush();
        } finally {
            outStream.close();
        }    
    }
    }

控制器代码：

    @Controller
    public class ExcelController    {

@RequestMapping(value = "/Excel", method = RequestMethod.POST)
protected ModelAndView generateCSV(HttpServletRequest request,
        HttpServletResponse response) throws Exception {
    BufferedReader in = null;
     try {
            URL oracle = new URL("http://service.com");
            URLConnection yc =null;
                yc = oracle.openConnection();
                  in = new BufferedReader(
                         new InputStreamReader(
                         yc.getInputStream()));
     }
     catch(Exception e){
         System.err.println(e);
     }
     ModelAndView mav = new ModelAndView();
     mav.setView(new ExcelReportView( in));
    return mav;
}
    }

日志输出：

    DispatcherServlet with name 'appServlet' processing POST request for [/App/Excel]
    Looking up handler method for path /App/Excel
    Returning handler method [protected org.springframework.web.servlet.ModelAndView com.package.ExcelController.generateCSV(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse) throws java.lang.Exception]
    Returning cached instance of singleton bean 'excelController'
    Rendering view [com.package.controllers.ExcelReportView: unnamed] in DispatcherServlet with name 'appServlet'
    Created Excel Workbook from scratch
    Title Id required
    Excel written successfully..
    Successfully completed request

编辑：

响应标头：

HTTP/1.1 200 OK
Server: Apache-Coyote/1.1
Pragma: private
Cache-Control: private, must-revalidate
Content-Disposition: attachment; filename=MyExcelSpreadsheet.xls
Content-Type: application/octet-stream;charset=ISO-8859-1
Content-Language: en-US
Transfer-Encoding: chunked
Date: Tue, 12 Mar 2013 16:36:52 GMT

Answer 1

您可以从控制器方法返回ModelAndView，将View 设置为AbstractExcelView 的实例。那么你根本不需要弄乱你的 XML。

编辑：添加一些附加信息： 我已经多次使用自定义 View 方法来处理 CSV 下载。

首先，您需要创建 AbstractExcelView 的实例化。您可以通过覆盖 buildExcelDeocument() 方法来实现。您将需要 POI 库，因为我认为它是必需的。例如：

@Override
public void buildExcelDocument(Map<String, Object> model, HSSFWorkbook workbook, 
                                HttpServletRequest request, HttpServletResponse response)
                                throws Exception {
    // Set the headers
    response.setHeader("Content-Type", "application/octet-stream");
    response.setHeader("Content-Disposition", "attachment; filename=MyExcelSpreadsheet.xls");

    // Here is where you will want to put the code to build the Excel spreadsheet

    OutputStream outStream = null;

    try {
        outStream = response.getOutputStream();
        workbook.write(outStream);
        outStream.flush();
    } finally {
        outStream.close();
    }       
}

接下来需要修改Controller方法

@RequestMapping(params = "actionMethod="+Constants.ACTION_METHOD_REPORT)
public ModelAndView generateCSV( 
        @ModelAttribute(Constants.REPORT_FORMBEAN_MODEL_ATTRIBUTE) FormBean formBean,
        ModelAndView mav,
        HttpServletRequest request, 
        HttpServletResponse response) {
    mav.setView(new MyExcelView( /* modify your constructor to pass in your data so the view can build the output */ ));

    return mav;
}

无需编辑上下文 XML、修改 bean 的连接方式、创建任何服务或任何东西。只需创建自定义视图的实例，传入构建电子表格所需的任何内容，然后在 ModelAndView 上设置视图。就这么简单。

编辑 - 您需要这样做...

您需要更改您的 AJAX 调用，以便您可以判断它是否已完成或有错误。你现在瞎了眼：

function AjaxCallForExcel(){
   $.ajax({
        type: 'POST',
        url: location.href + '/Excel',
        data: ({name:name }),
        complete: function(jqXHR,textStatus ) {
                               alert("Complete: "+textStatus );
                             },
        error: function(jqXHR,textStatus,errorThrown ) {
                             alert("Status: "+textStatus+"\nerror: "+errorThrown );
                          }
        }); 
   }