POI--初探

1. POI版本：poi-3.9-20121203
2. 创建XLS文件
   

   Workbook wb = new HSSFWorkbook();
   FileOutputStream fileOut = new FileOutputStream("e:/poi/demo.xls");
   wb.write(fileOut);
   fileOut.close();

3. 创建XLSX文件
   

   Workbook wb = new XSSFWorkbook();
   FileOutputStream fileOut = new FileOutputStream("e:/poi/demo.xlsx");
   wb.write(fileOut);
   fileOut.close();

4. 创建Sheet
   

   Workbook wb = new HSSFWorkbook();
   
   // Excel 工作表名称不能超过31个字符，并且不能包含以下字符：
   // 0x0000
   // 0x0003
   // colon (:)
   // backslash (\)
   // asterisk (*)
   // question mark (?)
   // forward slash (/)
   // opening square bracket ([)
   // closing square bracket (])
   Sheet sheet1 = wb.createSheet("new sheet");
   Sheet sheet2 = wb.createSheet("second sheet");
   
   //使用安全模式创建Excel工作表名称，即使用空格替代特殊字符
   String name = WorkbookUtil.createSafeSheetName("wei[]demo");
   Sheet sheet3 = wb.createSheet(name);
   
   FileOutputStream fileOut = new FileOutputStream("e:/poi/demo3.xls");
   wb.write(fileOut);
   fileOut.close();

5. 创建单元格
   

   Workbook wb = new HSSFWorkbook();
   //CreationHelper helper = wb.getCreationHelper();
   Sheet sheet = wb.createSheet("demo");
   
   //创建行，行号是以0为起始
   Row row = sheet.createRow(0);
   //创建单元格
   Cell cell = row.createCell(0);
   //添加数据
   cell.setCellValue(1);
   
   row.createCell(1).setCellValue(1.2);
   row.createCell(2).setCellValue("This is a String");
   row.createCell(3).setCellValue(true);
   
   FileOutputStream fileOut = new FileOutputStream("e:/poi/demo4.xls");
   wb.write(fileOut);fileOut.close();

6. 在单元格内添加日期类型
   

   Workbook wb = new HSSFWorkbook();
   CreationHelper helper = wb.getCreationHelper();
   Sheet sheet = wb.createSheet("new sheet");
   
   Row row = sheet.createRow(0);
   
   //创建一个单元格
   Cell cell = row.createCell(0);
   cell.setCellValue(new Date());
   //创建一个单元格的样式, 并设置默认样式
   CellStyle cellStyle = wb.createCellStyle();
   cellStyle.setDataFormat(
                       helper.createDataFormat().getFormat("yyyy-MM-dd hh:mm:ss")
                   );
   //创建第二个单元格
   cell = row.createCell(1);
   cell.setCellValue(new Date());
   cell.setCellStyle(cellStyle);    //绑定该单元格的样式
   
   cell = row.createCell(2);
           cell.setCellValue(Calendar.getInstance());
   cell.setCellStyle(cellStyle);
   
   FileOutputStream fileOut = new FileOutputStream("e:/poi/demo5.xls");
   wb.write(fileOut);
   fileOut.close();

7. 在单元格内添加不同类型的数据
   

   Workbook wb = new HSSFWorkbook();
   Sheet sheet = wb.createSheet("new sheet");
   
   Row row = sheet.createRow(2);
           row.createCell(0).setCellValue(1.1);    //double/float
           row.createCell(1).setCellValue(new Date()); //date
           row.createCell(2).setCellValue(Calendar.getInstance()); //Calendar
           row.createCell(3).setCellValue("This is String"); //String
           row.createCell(4).setCellValue(true); //boolean
           row.createCell(5).setCellType(Cell.CELL_TYPE_ERROR); //int
   
   FileOutputStream fileOut = new FileOutputStream("e:/poi/demo6.xls");
   wb.write(fileOut);
   fileOut.close()