Export Excel spreadsheet using the POI

一, Apache POI

        Apache POI is a free open source can have on in the Microsoft Office the Java API for reading and writing functions format. It supports read and write Microsoft Office files in various formats, but in practical application, we are using the most commonly used POI import and export to Excel spreadsheets.

        So this article will mainly talk about how to use the POI export Excel spreadsheets, and export dynamic data.

Second, it must import the jar package

        If we only need to import and export Excel spreadsheets, you only need to import the following three jar package: poi.jar; poi-ooxml.jar; poi-ooxml-schemas.jar.

        poi-3.9_Excel form required jar package download

Third, the simple export Excel spreadsheet example

public void exportExcel(HttpServletRequest request, HttpServletResponse response) throws IOException{
	/**  创建excel表格  */
	// 1.创建HSSFWorkbook对象(excel的文档对象)
	HSSFWorkbook wb = new HSSFWorkbook();
	// 2.建立新的sheet对象（excel的表单）
	HSSFSheet sheet = wb.createSheet("测试导出表格");
   
	sheet.setDefaultColumnWidth(20);         //设置缺省列宽
	sheet.setDefaultRowHeight((short)22);    // 设置缺省行高
	sheet.setDefaultRowHeightInPoints(22);
	
	/** 添加样式 */
	HSSFCellStyle cellDefStyle = wb.createCellStyle();   // 创建单元格样式
	cellDefStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);   // 设置左右居中
	cellDefStyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);    // 设置水平居中
	// 设置单元格边框（四周都有边框线）
	cellDefStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);    // HSSFCellStyle.BORDER_NONE:无边框线
	cellDefStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
	cellDefStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
	cellDefStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
	cellDefStyle.setWrapText(true);  // 自动换行
	// 设置文字样式
	HSSFFont fontDef = wb.createFont();
	fontDef.setFontName("宋体");    // 设置字体类型
	fontDef.setFontHeightInPoints((short)12);    // 设置字体大小
	fontDef.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);   // 设置字体加粗（fontDef.setBold(true)同样有用）
	fontDef.setUnderline(HSSFFont.U_SINGLE);    // 设置下划线
	cellDefStyle.setFont(fontDef);
  
	
	/** 设置标题  */
	// 1.在sheet里创建第一行，参数为行索引(excel的行)，可以是0～65535之间的任何一个
	int rowIndex = 0;    // 记录行号
	HSSFRow titleRow = sheet.createRow(rowIndex);
	titleRow.setHeightInPoints(30);    // 设置此行的行高
	// 2.创建单元格（excel的单元格，参数为列索引，可以是0～255之间的任何一个
	HSSFCell cell = titleRow.createCell(0);
	cell.setCellValue("测试导出Excel表格");    // 设置单元格内容
	// 3.设置单元格样式
	cell.setCellStyle(cellDefStyle);
	// 4.合并单元格CellRangeAddress构造参数依次表示起始行，截至行，起始列， 截至列
	sheet.addMergedRegion(new CellRangeAddress(rowIndex, rowIndex, 0, 5));
	++ rowIndex;
	
	/** 设置表格内容  */
	// 1.获取要填入表格的数据(根据自己实际情况获取数据)
	List<T> datas = 。。。
	for (T obj : datas) {
		HSSFRow contentRow = sheet.createRow(rowIndex);
		cell = contentRow.createCell(0);
		cell.setCellValue(obj.getName());
		cell.setCellStyle(cellDefStyle);
		cell = contentRow.createCell(1);
		cell.setCellValue(obj.getSex());
		cell.setCellStyle(cellDefStyle);
		sheet.setColumnWidth(colIndex -1,  256 * 20);    // 设置列宽(第一个参数是列号, 第二个参数是宽度)(setColumnWidth这个方法宽度的单位是字符数的256分之一)
		cell = contentRow.createCell(2);
		cell.setCellValue(obj.getAge());
		cell.setCellStyle(cellcontentStyle);
		sheet.setColumnWidth(colIndex - 1,  256 * 80);
		sheet.addMergedRegion(new CellRangeAddress(rowIndex, rowIndex, 2, 5));    // 合并单元格CellRangeAddress构造参数依次表示起始行，截至行，起始列，截止列
		++ rowIndex;
	}
	
	
	/** 设置行高（前面设置了默认行高，这里只需设置非默认部分，） */
	for (int i = 2; i < rowIndex - 1; i++) {
		HSSFRow row = sheet.getRow(i);
		row.setHeightInPoints(22);
	}
	
	/** 画表格对角线(表格中常有需要画对角线) */
	HSSFPatriarch patriarch = sheet.createDrawingPatriarch();
	HSSFClientAnchor anchor = new HSSFClientAnchor();   // 建立锚点（startRow, startCol, startX, startY, endRow, endCol, endX, endY）
	anchor.setAnchor((short) 1, 5, 0, 0, (short) 3, 6, 0, 0);
	HSSFSimpleShape line = patriarch.createSimpleShape(anchor);    // 建立一个简单的图形
	line.setShapeType(HSSFSimpleShape.OBJECT_TYPE_LINE);    // 线
	line.setLineStyle(HSSFShape.LINESTYLE_SOLID);    // 实线
	line.setLineWidth(HSSFShape.LINEWIDTH_ONE_PT);   // 设置线条粗细(HSSFShape.LINEWIDTH_ONE_PT表示1pt)
	
	//输出Excel文件
	OutputStream output = response.getOutputStream();
	response.reset();
	response.setCharacterEncoding("UTF-8");        
	String fileName = "导出Excel表格测试文件.xls";
	response.setContentType("application/vnd.ms-excel");
	response.setHeader("Content-disposition", "attachment; filename=" + dealFileName(request, fileName) );
	wb.write(output);
	output.close();
}

/** 处理导出文件名乱码的问题 */ 
public String dealFileName(HttpServletRequest request, String fileName) {
	String returnFileName = "";
	try {
		String userAgent = request.getHeader("USER-AGENT");
		if (userAgent != null && (userAgent.indexOf("MSIE") != -1 || userAgent.indexOf("Trident") != -1) {    // IE浏览器
			returnFileName = java.net.URLEncoder.encode(fileName, "UTF8");
		} else if (userAgent != null && userAgent.indexOf("Mozilla") != -1) {    // 火狐,chrome浏览器等
			returnFileName = new String(fileName.getBytes("UTF-8"), "iso-8859-1");
		}
	} catch (Exception e) {
		e.printStackTrace();
	}
	return returnFileName;
}

Fourth, the simple example of dynamic data derived

        When we want to export the data format is the same, we can create each row of data in the form of an object by object data list to dynamically export all data tables.

public String exportExcel() {
    try {
        // arg0：数据的集合
        List<?> data = getUserList();
        // arg1：集合中的数据的类型
        Class<?> clazz = User.class;
			
        // 创建工作本
        HSSFWorkbook workbook = new HSSFWorkbook();
        // 创建工作表
        HSSFSheet sheet = workbook.createSheet("Sheet1");
        // 创建第1行
        HSSFRow row = sheet.createRow(0);
			
        // 获取数据的字段列表
        Field[] fields = clazz.getDeclaredFields();
			
        // 创建?个单元格
        for (int i = 0; i < fields.length; i++) {
            // 设置当前字段可见
            fields[i].setAccessible(true);
            // 创建单元格
            HSSFCell cell = row.createCell((short) i);
            // 设计各单元格的数据类型（非必要）
            if ("java.lang.Integer".equals(fields[i].getType().getName())) {
                cell.setCellType(HSSFCell.CELL_TYPE_NUMERIC);
            } else {
                cell.setCellType(HSSFCell.CELL_TYPE_STRING);
            }
            // 添加数据
            cell.setCellValue(fields[i].getName());
        }
	
        // 循环添加数据
        for (int i = 0; i < data.size(); i++) {
            // 创建第?行
            row = sheet.createRow(i + 1);
            // 循环创建?个单元格
            for (int c = 0; c < fields.length; c++) {
                // 创建单元格
                HSSFCell cell = row.createCell((short) c);
                // 设计各单元格的数据类型（非必要）
                if ("java.lang.Integer".equals(fields[c].getType().getName())) {
                    cell.setCellType(HSSFCell.CELL_TYPE_NUMERIC);
                } else {
                    cell.setCellType(HSSFCell.CELL_TYPE_STRING);
                }
                // 添加数据
                cell.setCellValue(fields[c].get(data.get(i)).toString());
            }
        }
	
        // 将数据写到输出流对象中
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        workbook.write(out);
        // 通过输出流得到数据的byte[]
        byte[] bytes = out.toByteArray();
        // 关闭流
        out.close(); // 连接型资源都需要close()
        // 基于byte[]创建输入流对象，以返回给客户端
        setExcelStream(new ByteArrayInputStream(bytes));
        // 返回
        return "success";
    } catch (Exception e) {
        e.printStackTrace();
    }
    return "error";
}

Note: We can also custom annotation, whether to obtain each field of Chinese column name, and the field to be exported.