本篇所有资源来自于apache官方资源

http://poi.apache.org/components/spreadsheet/quick-guide.html

话不多说，实操，本篇只介绍基础，不涉及业务

1.导入依赖，版本自己选择合适的，不同版本可能方法不同，注意看官方网站

<!--excel表格 -->
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>3.17</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.17</version>
</dependency>

2.首先写控制层

@RestController
public class ExcelController {

    @Autowired
    private ExcelService excelService;

    @RequestMapping("exportExcelMode")
    public void exportExcelMode(HttpServletResponse response) {
        OutputStream outputStream = null;
        try {
            outputStream = response.getOutputStream();
            response.setContentType("application/octet-stream");
            response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode("用户表" + ".xlsx", "utf-8"));
            excelService.exportExcelMode(outputStream);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

2.写导出方法exportExcelMode

@Service
public class ExcelService {
    public void exportExcelMode(OutputStream outputStream){
        try {
            //用来做第一行的标题行
            String[] field =new String[]{"序号","用户名","密码"};
            //建立工作区
            XSSFWorkbook workbook = new XSSFWorkbook();
            //创建工作表
            XSSFSheet sheet = workbook.createSheet("用户册");
            //创建第一行
            XSSFRow row = sheet.createRow(0);
            //创建样式
            XSSFCellStyle cellStyle = workbook.createCellStyle();
            Font font = workbook.createFont();
            font.setFontName("宋体");
            //设置字体大小
            font.setFontHeightInPoints((short) 11);
            //设置字体样式
            cellStyle.setFont(font);
            cellStyle.setBorderBottom(BorderStyle.THIN); //下边框
            cellStyle.setBorderLeft(BorderStyle.THIN);//左边框
            cellStyle.setBorderTop(BorderStyle.THIN);//上边框
            cellStyle.setBorderRight(BorderStyle.THIN);//右边框
            //垂直居中
            cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
            //更多样式去官网上看
            for (int i=0;i<field.length;i++){
                //获取列
                XSSFCell cell = row.createCell(i);
                //给该列设置值
                cell.setCellValue(field[i]);
                //设置该列的样式
                cell.setCellStyle(cellStyle);
                //设置列宽
                sheet.setColumnWidth(i,256*30);
            }
            //创建第二行
            row = sheet.createRow(1);
            //第二行第一列
            XSSFCell cell = row.createCell(0);
            cell.setCellStyle(cellStyle);
            cell.setCellValue(1);
            //第二行第二列
            cell = row.createCell(1);
            cell.setCellStyle(cellStyle);
            cell.setCellValue("zhangSan");
            //第二行第三列
            cell = row.createCell(2);
            cell.setCellStyle(cellStyle);
            cell.setCellValue("123456");
            workbook.setSheetName(0,"用户表");
            workbook.write(outputStream);
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            if(outputStream!=null){
                try {
                    outputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

3.测试

4.总结

   更多的操作，例如合并单元格什么的可以参考官方文档，http://poi.apache.org/components/spreadsheet/quick-guide.html

这部分一般采用循环生成，有数组对象，直接遍历