sql查询结果导出到excel文件保存

    public static void exportData(String sql,String path,String fileName) throws SQLException, ClassNotFoundException, IOException {
        File file1=new File(path);
        if (!file1.exists()){
            file1.mkdir();
        }
        Connection conn1=DataUtil.getConnection();
        PreparedStatement ps=conn1.prepareStatement(sql+" limit 1");
        ResultSet rs=ps.executeQuery();
        if(!rs.next()){
            return; //没有数据结束导出
        }
        ResultSetMetaData rsmd=rs.getMetaData();
        int count=rsmd.getColumnCount();    //获取字段数
        String[] columnName=new String[count];
        for(int i=0;i<count;i++){
            columnName[i]=rsmd.getColumnName(i+1);     //获取字段名
        }
        ps.close();
        rs.close();
        String fileType="xlsx";
        Workbook wb=new SXSSFWorkbook(1000); //使用xlsx格式
        Sheet sheet1=wb.createSheet("sheet1");
        Row row1=sheet1.createRow(0);
        Cell[] cell1=new Cell[count];       //设置表头
        for (int i=0;i<count;i++){
            cell1[i]=row1.createCell(i);
            cell1[i].setCellValue(columnName[i]);
        }

        PreparedStatement ps3=conn1.prepareStatement(sql,ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);