基於Spring Mvc實現的Excel文件上傳下載

最近工作遇到一個需求，需要下載excel模板，編輯后上傳解析存儲到數據庫。因此為了更好的理解公司框架，我就自己先用spring mvc實現了一個樣例。

基礎框架

之前曾經介紹過一個最簡單的spring mvc的項目如何搭建，傳送門在這里。

這次就基於這個工程，繼續實現上傳下載的小例子。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 創建upload download接口
• 4 注入multipartResolver bean
• 5 在upload中使用HttpServletRequest獲取文件流，通過WorkBook進行解析
• 6 在download中通過HttpServerResponse返回文件流，實現下載

頁面

頁面很簡單，其實就是一個form標簽，需要注意的是：

• form中enctype="multipart/form-data"
• action指定訪問的url
• input中需要設置name屬性，這樣后端才能獲取到文件對象

<form role="form" action="/upload" method="POST" enctype="multipart/form-data">
    <div class="form-group">
        <label for="file">上傳文件</label>
        <input type="file" id="file" name="file">
    </div>
    <button type="submit" class="btn btn-default">提交</button>
</form>

引入commons-fileupload、jxl等工具包

涉及的jar包有：

• commons-fileupload 用於獲取上傳文件
• jxl 用於解析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>

Xml的配置

在web.xml中需要配置默認的訪問頁面，因為之前已經設置過攔截的請求是/，因此如果不設置所有的靜態頁面都會被攔截下來。

<welcome-file-list>
	<welcome-file>index.html</welcome-file>
</welcome-file-list>

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>

上傳代碼

@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());
        //遍歷Sheet頁
        Arrays.stream(workbook.getSheets())
                .forEach(sheet -> {
                    int size = sheet.getRows();
                    for(int i=0; i<size; i++){
                        //遍歷每一行，讀取每列信息
                        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();
    }

下載代碼

@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();
    }

模板類

static class ExcelUtils {
        public static WritableWorkbook createTemplate(OutputStream output) throws IOException, WriteException {
            WritableWorkbook writableWorkbook= Workbook.createWorkbook(output);
            WritableSheet wsheet = writableWorkbook.createSheet("測試title", 0);


            CellFormat cf = writableWorkbook.getSheet(0).getCell(1, 0).getCellFormat();
            WritableCellFormat wc = new WritableCellFormat();
            // 設置居中
            wc.setAlignment(Alignment.CENTRE);
            // 設置邊框線
//        wc.setBorder(Border.ALL, BorderLineStyle.THIN);
            wc.setBackground(jxl.format.Colour.GREEN);

            Label nc0 = new Label(0, 0, "標題1",wc);//Label(x,y,z)其中x代表單元格的第x+1列，第y+1行, 單元格的內容是z
            Label nc1 = new Label(1, 0, "標題2",wc);
            Label nc2 = new Label(2, 0, "標題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;
        }
    }

最后貢獻下相關的代碼

有需要的可以拿去參考

網盤下載鏈接