JAVA将执行sql结果导入excel

Java实现将查询的sql结果集导入excel,用到jxl.jar包

public String queryResultToExcel(String sql,String filename,OutputStream os) {
        Connection conn = null;
        Statement sm = null;
        ResultSet rs = null;
        try {
            conn = getConnection();
            sm = conn.createStatement();
            rs = sm.executeQuery(sql);
            ResultSetMetaData rsmd = rs.getMetaData();
            WritableWorkbook wwb = Workbook.createWorkbook(os); // 建立excel文件
            WritableSheet sheet = wwb.createSheet(filename, 10); // 创建一个工作表
            // 设置单元格的文字格式
            WritableFont wf = new WritableFont(WritableFont.ARIAL, 10, WritableFont.BOLD, false, UnderlineStyle.NO_UNDERLINE, Colour.BLACK);
            WritableCellFormat wcf = new WritableCellFormat(wf);
            wcf.setVerticalAlignment(VerticalAlignment.CENTRE);
            wcf.setAlignment(Alignment.LEFT);
 
            // 格式化数据--NUMBER类型
            NumberFormat numberFormat = new NumberFormat(###0.0#######); 
            WritableCellFormat cellFormatNumber = new WritableCellFormat(numberFormat);
            cellFormatNumber.setVerticalAlignment(VerticalAlignment.CENTRE);
            cellFormatNumber.setAlignment(Alignment.RIGHT);
             
            NumberFormat numberFormat2 = new NumberFormat(###0); 
            WritableCellFormat cellFormatNumber2 = new WritableCellFormat(numberFormat2); 
            cellFormatNumber2.setVerticalAlignment(VerticalAlignment.CENTRE);
            cellFormatNumber2.setAlignment(Alignment.RIGHT);
             
            // 格式化数据--DATE类型
            DateFormat dateFormat=new DateFormat(yyyy-MM-dd);
            WritableCellFormat cellFormatDate = new WritableCellFormat(dateFormat); 
            cellFormatDate.setVerticalAlignment(VerticalAlignment.CENTRE);
            cellFormatDate.setAlignment(Alignment.CENTRE);
            // 格式化数据--文本
            WritableCellFormat  cellTextFormat = new WritableCellFormat(NumberFormats.TEXT);
            cellTextFormat.setAlignment(Alignment.CENTRE);
            cellTextFormat.setVerticalAlignment(VerticalAlignment.CENTRE);
             
            // 表体数据
            boolean flag = true;
            int r = 1;
            int c = 0;
            int columns = rsmd.getColumnCount();
            //缓存最大标题宽度
            Vector<integer> colWidth = new Vector<integer>();
            for(int i = 1; i <= columns; i++){
                colWidth.add(0);
            }
             
            while (rs.next()) {
                for (int i = 1; i <= columns; i++) {
                    //添加表头数据
                    if(flag){
                        String key = rsmd.getColumnName(i).toLowerCase();
                        sheet.setColumnView(c, key.getBytes(GBK).length + 4);
                        sheet.addCell(new Label(c, 0, key,wcf));
                        colWidth.set(i-1, key.getBytes(GBK).length); //缓存每列第一行数据的宽度
                    }
                 
                    //设置列宽--如果下一列的数据比前一列宽，则保存最大宽度
                    if(rs.getString(i) != null){
                        if(colWidth.get(i-1)<rs.getstring(i).length()){ auto-generated="" block="" c="0;" catch="" else="" filenotfoundexception="" finally="" flag="false;" if="" ioexception="" new="" pre="" return="" sqlexception="" todo="" try="" writeexception=""><p> </p></rs.getstring(i).length()){></integer></integer>