jxl導入，導出

pom.xml引入包：
    <dependency>
        <groupId>net.sourceforge.jexcelapi</groupId>
        <artifactId>jxl</artifactId>
        <version>2.6.12</version>
    </dependency>

代碼：
/**
	 * 導入Excel數據

	 */
    @PostMapping("import")
	public AjaxResult importTradLine(@RequestParam(value = "file", required = false)MultipartFile file,@RequestParam String userId){
    	
    	int b=0;
    	Date date = new Date();
		DateFormat df = new SimpleDateFormat("hh:mm:ss");
		SimpleDateFormat dfs = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
		
		try {
			// 1.獲取用戶上傳的文件
			Workbook workbook = Workbook.getWorkbook(file.getInputStream());
			
			if (workbook == null) {
				return error("導入Excel爲空");
			}
			
			// 2.獲取工作簿sheet
			Sheet sheet = workbook.getSheet(0);
			// 3.獲取總行數
			int rows = sheet.getRows();
			System.out.println("rows:" + rows);
			for (int i = 1; i < rows; i++) {
//			Students students = new Students();
				//Cell oCell= oFirstSheet.getCell(j,i);//需要注意的是這裏的getCell方法的參數，第一個是指定第幾列，第二個參數纔是指定第幾行  
				TradeLine tradeLine= new TradeLine();
				String company2 = sheet.getCell(1, i).getContents();
				String c1 =company2.replaceAll("\\s", "");
				String c2 =company.replaceAll("\\s", "");
				if (!c1.equals(c2)) {
					continue;
				}
				tradeLine.setSupplier(c1);
				tradeLine.setUnloadCompany(sheet.getCell(2, i).getContents());
				tradeLine.setGoods(sheet.getCell(3, i).getContents());
				tradeLine.setCarNumber(sheet.getCell(4, i).getContents());
				tradeLine.setUnloadNumber(sheet.getCell(5, i).getContents());
				tradeLine.setPrice(Double.parseDouble(sheet.getCell(6,i).getContents()));
				tradeLine.setTon(Double.parseDouble(sheet.getCell(7, i).getContents()));
			  tradeLine.setAmounts(Double.parseDouble(sheet.getCell(8,i).getContents()));
				
				String unloadTime=sheet.getCell(9, i).getContents();
				String begin = unloadTime + " " + df.format(date);
				Date d = dfs.parse(begin);
				tradeLine.setUnloadDate(d);
				tradeLine.setCreateDate(new Date());
				// 4.添加到數據庫中
				int a =tradeLineService.insert(tradeLine);
				b++;
			}
			// 5.關閉資源
			workbook.close();
		} catch (Exception e) {
			e.printStackTrace();
		} 
		System.out.println("共導入了" + b + "條");
		return success("共成功執行了" + b + "條");
	}

	
	/**
	 * 下載導入數據模板
	 */
    @GetMapping("import/template")
    public AjaxResult exportTemplate(HttpServletRequest request,HttpServletResponse response) throws Exception {
        // 1.文件下載響應頭
        response.setContentType("application/msexcel");
        response.addHeader("Content-Disposition", "attachment; filename=" + URLEncoder.encode("模板導出.xls", "UTF-8"));
        response.setCharacterEncoding("utf-8");
        // 2.響應到瀏覽器
        WritableWorkbook workbook = Workbook.createWorkbook(response.getOutputStream());
        
        /**
		 * 定義單元格樣式
		 */
		WritableFont wf_title = new WritableFont(WritableFont.ARIAL, 12,
				WritableFont.BOLD, false, UnderlineStyle.NO_UNDERLINE,
				jxl.format.Colour.RED); // 定義格式 字體 下劃線 斜體 粗體 顏色
		WritableFont wf_head = new WritableFont(WritableFont.ARIAL, 12,
				WritableFont.BOLD, false, UnderlineStyle.NO_UNDERLINE,
				jxl.format.Colour.BLACK); // 定義格式 字體 下劃線 斜體 粗體 顏色
		WritableFont wf_table = new WritableFont(WritableFont.ARIAL, 8,
				WritableFont.BOLD, false, UnderlineStyle.NO_UNDERLINE,
				jxl.format.Colour.BLACK); // 定義格式 字體 下劃線 斜體 粗體 顏色
	
		WritableCellFormat wcf_title = new WritableCellFormat(wf_title); // 單元格定義
		wcf_title.setBackground(jxl.format.Colour.BLACK); // 設置單元格的背景顏色
		wcf_title.setAlignment(jxl.format.Alignment.CENTRE); // 設置對齊方式
	
		WritableCellFormat wcf_head = new WritableCellFormat(wf_head); 
		wcf_head.setBackground(jxl.format.Colour.BLACK);
		wcf_head.setAlignment(jxl.format.Alignment.CENTRE); 
	
		WritableCellFormat wcf_table = new WritableCellFormat(wf_table); 
		wcf_table.setBackground(jxl.format.Colour.BLACK); 
		wcf_table.setAlignment(jxl.format.Alignment.CENTRE); 
        
        
        // 創建工作簿sheet
        WritableSheet sheet = workbook.createSheet("模板", 0);
        // 3.設置column名
        sheet.addCell(new Label(0, 0, "序號",wcf_head));
        sheet.addCell(new Label(1, 0, "供應單位",wcf_head));
        sheet.addCell(new Label(2, 0, "卸貨廠家",wcf_head));
        sheet.addCell(new Label(3, 0, "貨品種類",wcf_head));
        sheet.addCell(new Label(4, 0, "車牌號碼",wcf_head));
        sheet.addCell(new Label(5, 0, "卸貨磅單",wcf_head));
        sheet.addCell(new Label(6, 0, "貨品單價(元/噸)",wcf_head));
        sheet.addCell(new Label(7, 0, "卸貨噸數",wcf_head));
        sheet.addCell(new Label(8, 0, "總金額(元)",wcf_head));
        sheet.addCell(new Label(9, 0, "卸貨日期",wcf_head));

        // 4.把覈保的數據填充到工作簿中 service調用selectExport()查詢數據庫
        System.out.println("開始導出...");
        long s1 = System.currentTimeMillis();
       
        // 5.寫入數據
        workbook.write();
        // 6.關閉資源
        workbook.close();

        long s2 = System.currentTimeMillis();
        long time = s2 - s1;
        System.out.println("導出完成！消耗時間：" + time + "毫秒");
        return null;
    }

 備註：如果是查詢數據庫數據，導出數據，在導出模板代碼塊中，加入個循環插入即可，不再重複寫代碼了。