最近工作遇到一个需求,需要下载excel模板,编辑后上传解析存储到数据库。因此为了更好的理解公司框架,我就自己先用spring mvc实现了一个样例。
基础框架
之前曾经介绍过一个最简单的spring mvc的项目如何搭建,传送门在这里。
这次就基于这个工程,继续实现上传下载的小例子。需要做下面的事情:
1 增加index.html,添加form提交文件
2 引入commons-fileupload、commons-io、jxl等工具包
3 创建upload download接口
4 注入multipartResolver bean
5 在upload中使用HttpServletRequest获取文件流,通过WorkBook进行解析
6 在download中通过HttpServerResponse返回文件流,实现下载
页面
页面很简单,其实就是一个form标签,需要注意的是:
- form中enctype="multipart/form-data"
- action指定访问的url
- input中需要设置name属性,这样后端才能获取到文件对象
- <form role="form" action="/upload" method="POST" enctype="multipart/form-data">
- <div class="form-group">
- <label for="file">上传文件</label>
- <input type="file" id="file" name="file">
- </div>
- <button type="submit" class="btn btn-default">提交</button>
- </form>
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引入commons-fileupload、jxl等工具包
涉及的jar包有:
- commons-fileupload 用于获取上传文件
- jxl 用于解析excel
- <!-- springframework begins -->
- <dependency>
- <groupId>org.springframework</groupId>
- <artifactId>spring-webmvc</artifactId>
- <version>4.2.4.RELEASE</version>
- </dependency>
- <dependency>
- <groupId>org.springframework</groupId>
- <artifactId>spring-context</artifactId>
- <version>4.2.4.RELEASE</version>
- </dependency>
- <dependency>
- <groupId>javax.servlet</groupId>
- <artifactId>javax.servlet-api</artifactId>
- <version>4.0.0-b01</version>
- </dependency>
- <!-- https://mvnrepository.com/artifact/commons-io/commons-io -->
- <dependency>
- <groupId>commons-io</groupId>
- <artifactId>commons-io</artifactId>
- <version>2.5</version>
- </dependency>
- <!-- https://mvnrepository.com/artifact/commons-fileupload/commons-fileupload -->
- <dependency>
- <groupId>commons-fileupload</groupId>
- <artifactId>commons-fileupload</artifactId>
- <version>1.3.2</version>
- </dependency>
- <!-- https://mvnrepository.com/artifact/jexcelapi/jxl -->
- <dependency>
- <groupId>jexcelapi</groupId>
- <artifactId>jxl</artifactId>
- <version>2.6</version>
- </dependency>
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Xml的配置
在web.xml中需要配置默认的访问页面,因为之前已经设置过拦截的请求是/,因此如果不设置所有的静态页面都会被拦截下来。
- <welcome-file-list>
- <welcome-file>index.html</welcome-file>
- </welcome-file-list>
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在spring的配置文件中,加入CommonsMultipartResolver的bean。
- <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
- <!-- set the max upload size100MB -->
- <property name="maxUploadSize">
- <value>104857600</value>
- </property>
- <property name="maxInMemorySize">
- <value>4096</value>
- </property>
- </bean>
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上传代码
- @RequestMapping("upload")
- public void upload(HttpServletRequest request, HttpServletResponse response) throws IOException, BiffException, WriteException {
- MultipartHttpServletRequest mRequest = (MultipartHttpServletRequest) request;
- MultipartFile file = mRequest.getFile("file");
- Workbook workbook = Workbook.getWorkbook(file.getInputStream());
- //遍历Sheet页
- Arrays.stream(workbook.getSheets())
- .forEach(sheet -> {
- int size = sheet.getRows();
- for(int i=0; i<size; i++){
- //遍历每一行,读取每列信息
- Arrays.stream(sheet.getRow(i)).forEach(cell -> System.out.println(cell.getContents().equals("")?'空':cell.getContents()));
- }
- });
- response.setHeader("Content-Disposition", "attachment; filename=return.xls");
- WritableWorkbook writableWorkbook = ExcelUtils.createTemplate(response.getOutputStream());
- writableWorkbook.write();
- writableWorkbook.close();
- }
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下载代码
- @RequestMapping("download")
- public void download(HttpServletRequest request, HttpServletResponse response) throws IOException, BiffException, WriteException {
- response.setHeader("Content-Disposition", "attachment; filename=template.xls");
- WritableWorkbook writableWorkbook = ExcelUtils.createTemplate(response.getOutputStream());
- writableWorkbook.write();
- writableWorkbook.close();
- }
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模板类
- static class ExcelUtils {
- public static WritableWorkbook createTemplate(OutputStream output) throws IOException, WriteException {
- WritableWorkbook writableWorkbook= Workbook.createWorkbook(output);
- WritableSheet wsheet = writableWorkbook.createSheet("测试title", 0);
- CellFormat cf = writableWorkbook.getSheet(0).getCell(1, 0).getCellFormat();
- WritableCellFormat wc = new WritableCellFormat();
- // 设置居中
- wc.setAlignment(Alignment.CENTRE);
- // 设置边框线
- // wc.setBorder(Border.ALL, BorderLineStyle.THIN);
- wc.setBackground(jxl.format.Colour.GREEN);
- Label nc0 = new Label(0, 0, "标题1",wc);//Label(x,y,z)其中x代表单元格的第x+1列,第y+1行, 单元格的内容是z
- Label nc1 = new Label(1, 0, "标题2",wc);
- Label nc2 = new Label(2, 0, "标题3",wc);
- Label nc3 = new Label(0, 1, "dddd");
- Label nc4 = new Label(1, 1, "ffff");
- wsheet.addCell(nc0);
- wsheet.addCell(nc1);
- wsheet.addCell(nc2);
- wsheet.addCell(nc3);
- wsheet.addCell(nc4);
- return writableWorkbook;
- }
- }
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最后贡献下相关的代码
有需要的可以拿去参考
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