Excel导出文件

1、先导入pom.xml

<!-- https://mvnrepository.com/artifact/org.apache.poi/poi --><dependency>    <groupId>org.apache.poi</groupId>    <artifactId>poi</artifactId>    <version>3.7</version></dependency><!-- https://mvnrepository.com/artifact/org.apache.commons/commons-io --><dependency>    <groupId>org.apache.commons</groupId>    <artifactId>commons-io</artifactId>    <version>1.3.2</version></dependency>

2、java文件

public String ExcelDownload() {        List<User> userList= getAllUser();//获取信息        String filename = mercNo + "_信息_" + TimeUtil.getTime("yyyyMMddHHmmss") + ".xls";// 导出文件名        HSSFWorkbook workBook = null;        String[] cellTitle = { "账号Id", "名字 ", "密码", "权限" };        try {            workBook = new HSSFWorkbook();// 创建工作薄            HSSFSheet sheet = workBook.createSheet();            workBook.setSheetName(0, "信息");// 工作簿名称            HSSFFont font = workBook.createFont();            font.setColor(HSSFFont.COLOR_NORMAL);            font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);            HSSFCellStyle cellStyle = workBook.createCellStyle();// 创建格式            cellStyle.setFont(font);            cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);            cellStyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);            // 创建第一行标题            HSSFRow titleRow = sheet.createRow((short) 0);// 第一行标题            for (int i = 0, size = cellTitle.length; i < size; i++) {// 创建第1行标题单元格                switch (i) {                case 0:                    sheet.setColumnWidth(0, 5000);                    break;                case 1:                    sheet.setColumnWidth(1, 10000);                    break;                case 2:                    sheet.setColumnWidth(2, 9000);                    break;                case 3:                    sheet.setColumnWidth(3, 6000);                    break;                }                HSSFCell cell = titleRow.createCell(i, 0);                cell.setCellStyle(cellStyle);                cell.setCellValue(cellTitle[i]);            }            // 从第二行开始写入数据            // 注：此处如果数据过多，会抛出java.lang.IllegalStateException异常：The maximum            // number of cell styles was exceeded.            // You can define up to 4000 styles in a .xls workbook。这是是由于cell            // styles太多create造成，故一般可以把cellstyle设置放到循环外面            if (StatementList != null && !StatementList.isEmpty()) {                HSSFCellStyle style = workBook.createCellStyle();// 创建格式                for (int i = 0, size = StatementList.size(); i < size; i++) {                    User entity = userList.get(i);                    HSSFRow row = sheet.createRow((short) i + 1);                    for (int j = 0, length = cellTitle.length; j < length; j++) {                        HSSFCell cell = row.createCell(j, 0);// 在上面行索引0的位置创建单元格                        cell.setCellType(HSSFCell.CELL_TYPE_STRING);// 定义单元格为字符串类型                        switch (j) {// 在单元格中输入一些内容                        case 0:                            cell.setCellValue(entity.getId());                            style.setAlignment(HSSFCellStyle.ALIGN_CENTER);                            cell.setCellStyle(style);                            break;                        case 1:                            cell.setCellValue(entity.getUsername());                            style.setAlignment(HSSFCellStyle.ALIGN_CENTER);                            cell.setCellStyle(style);                            break;                        case 2:                            cell.setCellValue(entity.getPassword());                            style.setAlignment(HSSFCellStyle.ALIGN_CENTER);                            cell.setCellStyle(style);                            break;                        case 3:                            cell.setCellValue(entity.getPower());                            style.setAlignment(HSSFCellStyle.ALIGN_CENTER);                            cell.setCellStyle(style);                            break;                        }                    }                }            String path = "D:\\test\\";            String filepath = path + "\\" + filename;            File file = new File(filepath);            File file123 = new File(filepath);            FileOutputStream outStream = new FileOutputStream(file123);            workBook.write(outStream);            outStream.flush();            outStream.close();        } catch (Exception e) {            System.out.println("文件导出发生异常！异常原因：" + e.getMessage());            e.printStackTrace();        }        return filename;    }