package exceltest;

import java.io.*;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddress;

public class excel25 {
    public excel25(){
        try{

            InputStream inp = new FileInputStream("d:/temp/siyodaka.xls");
            Workbook wb = WorkbookFactory.create(inp);
            Sheet sheet = wb.getSheetAt(0);
            int x = sheet.getNumMergedRegions();
            //コピー元の4行目から43行目を10回コピーする
            for(int i = 0; i < 10; i++){
                sheet = sheetCopy(sheet, 3, 43, i, x);
            }
            FileOutputStream fileOut = new FileOutputStream("d:/temp/workbook.xls");
            wb.write(fileOut);
            fileOut.close();
        }catch(Exception e){
            System.out.println(e.toString());
        }
    }
/*
 * sheet    worksheet
 * st       コピーの開始行(start from 0)
 * en       コピーの最終行(end from 1)
 * cnt      コピーの位置
 * x        コピー元のマージの個数
 */
    public Sheet sheetCopy(Sheet sheet, int st, int en, int cnt, int x){
        Row row = null, row2 = null;
        Cell cell = null, cell2 = null;
        CellStyle cellstyle = null;
        short height = 0;
        for(int i = st; i < en; i++){
            row = sheet.getRow(i);
            height = row.getHeight();
            if (row != null){
                row2 = sheet.createRow((en - st) * cnt + i);
                row2.setHeight(height);
                for(int j = 0; j < row.getLastCellNum(); j++){
                    cell = row.getCell(j);
                    if(cell != null){
                        cell2 = row2.createCell(j);
                        cellstyle = cell.getCellStyle();
                        cell2.setCellStyle(cellstyle);
                        switch(cell.getCellType()) {
                            case Cell.CELL_TYPE_STRING:                                       cell2.setCellValue(cell.getRichStringCellValue());
                            break;
                            case Cell.CELL_TYPE_NUMERIC:
                                if(DateUtil.isCellDateFormatted(cell)) {

cell2.setCellValue(cell.getDateCellValue());
                                }else{

cell2.setCellValue(cell.getNumericCellValue());
                                }
                            break;
                            case Cell.CELL_TYPE_FORMULA:
                                cell2.setCellFormula(cell.getCellFormula());
                            break;
                            case Cell.CELL_TYPE_BOOLEAN:

cell2.setCellValue(cell.getBooleanCellValue());
                            break;
                        }
                    }
                }
            }
        }
        CellRangeAddress cra = null;
        for(int i = 0; i < x; i++){
            cra = sheet.getMergedRegion(i);
            if (cra.getFirstRow() > st){
                cra.setFirstRow(cra.getFirstRow() + (en - st) * cnt);
                cra.setLastRow(cra.getLastRow() + (en - st) * cnt);
                sheet.addMergedRegion(cra);
            }
        }
        return sheet;
    }

    public static void main(String[] args) {
        // TODO code application logic here
        new excel25();
    }

}

Attention:

      1,从cell1得到的cellStyle,赋给cell2,当cell2修改cellStyle,cell1也会跟着变动。

      2,Excel模板继承列属性，不继承行属性，为修改样式而人为添加的单个cell，应添加在模板之外的列，否而修改之后，相应的列也会发生样式变动。

      3，当sheet名或者cellvalue是String型时，需先设置编码方式，后再赋值，否则会出现乱码。

        hssBook.setSheetName(0, keyList.get(0).getSchoolName(), HSSFWorkbook.ENCODING_UTF_16);

        final HSSFCell settingNameCell = row5.createCell(colunmIndex);
        settingNameCell.setEncoding(HSSFCell.ENCODING_UTF_16);
        settingNameCell.setCellValue(String.format("%s%s", beforeName, l.getName()));

       4，自动换行功能

         HSSFCellStyle  cs=wb.createCellStyle();  
         cs.setWrapText(true);  
         cell.setCellStyle(cs);

       5，斜线       

          这个地方是用来在单元格里画斜线的， 原理是在指定的两个点之间画线，然后默认情况此线会随着单元格的变化而变化

          HSSFPatriarch patriarch = st.createDrawingPatriarch();

          HSSFClientAnchor anchor = new HSSFClientAnchor();

          anchor.setAnchor(cell.getCellNum(), row.getRowNum(), 0, 0, (short) (cell.getCellNum() + 1),row.getRowNum() + 1, 0, 0);

          patriarch.createSimpleShape(anchor);

          0，0为 x，y坐标

        6，合并单元格

           hssSheet.addMergedRegion(new Region(rowIndex1,colunmIndex1, rowIndex2, colunmIndex2));