POI基本操作

1、读取excel文件

InputStream is = new FileInputStream(filesrc);
POIFSFileSystem fs = new POIFSFileSystem(is);
HSSFWorkbook wb = new HSSFWorkbook(fs);
HSSFSheet sheet = wb.getSheetAt(0);

2、获取全部行数

int rows = sheet.getLastRowNum();

3、创建工作簿

Workbook wb = new HSSFWorkbook();//定义一个新的工作簿
FileOutputStream fileOut = new FileOutputStream("d:\\poiDemo.xls");
wb.write(fileOut);
fileOut.close();

4、创建sheet页

Workbook wb = new HSSFWorkbook();//定义一个新的工作簿wb.createSheet("FirstSheet");//创建一个sheet页
wb.createSheet("SecondSheet");//创建第二个sheet页
FileOutputStream fileOut = new FileOutputStream("d:\\poiSheetDemo.xls");

5、创建单元格

Workbook wb = new HSSFWorkbook();
        Sheet sheet = wb.createSheet("firstSheet");
        Row row = sheet.createRow(0);//创建一行
        Cell cell = row.createCell(0);//创建一个单元格
        cell.setCellValue(1);

        row.createCell(1).setCellValue(1.2);//创建一个单元格第二列，值是1.2
        row.createCell(2).setCellValue("这是一个字符串");//创建一个单元格第三列，值是1.2

        FileOutputStream fileOut = new FileOutputStream("d:\\poiSheet.xls");
        wb.write(fileOut);
        fileOut.close();

6、遍历工作簿

public static void main(String[] args) throws Exception {
        InputStream is = new FileInputStream("d:\\遍历名单.xls");
        POIFSFileSystem fs = new POIFSFileSystem(is);
        HSSFWorkbook wb = new HSSFWorkbook(fs);
        HSSFSheet hssfSheet = wb.getSheetAt(0);
        if(hssfSheet==null){
            return;
        }
        //遍历行row
        for(int rowNum = 0;rowNum<=hssfSheet.getLastRowNum();rowNum++){
            HSSFRow hssfRow = hssfSheet.getRow(rowNum);
            if(hssfRow==null){
                continue;
            }
            //遍历裂cell
            for(int cellNum = 0;cellNum<=hssfRow.getLastCellNum();cellNum++){
                HSSFCell hssfCell = hssfRow.getCell(cellNum);
                if(hssfCell==null){
                    continue;
                }
                System.out.print(" "+getValue(hssfCell));
            }
            System.out.println();
        }

    }

    private static String getValue(HSSFCell hssfCell){
        if(hssfCell.getCellType()==HSSFCell.CELL_TYPE_BOOLEAN){
            return String.valueOf(hssfCell.getBooleanCellValue());
        }else if(hssfCell.getCellType()==HSSFCell.CELL_TYPE_NUMERIC){
            return String.valueOf(hssfCell.getNumericCellValue());
        }else{
            return String.valueOf(hssfCell.getStringCellValue());
        }
    }

7、文本提取

InputStream is = new FileInputStream("d:\\遍历名单.xls");
POIFSFileSystem fs = new POIFSFileSystem(is);
HSSFWorkbook wb = new HSSFWorkbook(fs);

ExcelExtractor excelExtractor = new ExcelExtractor(wb);
excelExtractor.setIncludeSheetNames(false);//不需要sheet页的名字
System.out.println(excelExtractor.getText());

8、单元格合并

Workbook wb = new HSSFWorkbook();
        Sheet sheet = wb.createSheet("sheet1");
        Row row = sheet.createRow(1);

        Cell cell = row.createCell(1);
        cell.setCellValue("单元格合并");

        sheet.addMergedRegion(new CellRangeAddress(1,2,1,2));//起始行，结束行，起始列，结束列

9、读取和重写工作簿

InputStream inp = new FileInputStream("d:\\demo13.xls");
        POIFSFileSystem fs = new POIFSFileSystem(inp);
        Workbook wb = new HSSFWorkbook(fs);
        Sheet sheet = wb.getSheetAt(0);//获取第一个sheet
        Row row = sheet.getRow(0);
        Cell cell =row.getCell(0);
        if(cell==null){
            cell = row.createCell(3);

        }
        cell.setCellType(Cell.CELL_TYPE_STRING);
        cell.setCellValue("测试单元格");

        FileOutputStream fileOut = new FileOutputStream("d:\\demo13.xls");
        wb.write(fileOut);
        fileOut.close();