POI进行跨行需要用到对象HSSFSheet对象,现在就当我们程序已经定义了一个HSSFSheet对象sheet。

跨第1行第1个到第2个单元格的操作为
sheet.addMergedRegion(new Region(0,(short)0,0,(short)1));

跨第1行第1个到第2行第1个单元格的操作为
sheet.addMergedRegion(new Region(0,(short)0,1,(short)0));


重点注意事项:
1.单元格CELL和ROW对象下标都是从0开始的。
2.单元格合并时Region(1,2,3,4)第1个值的行号必须要比3位置的行号小,如果大于3就不能正常合并单元格
3.合并单元格的时候要合并的单单元格必须先创建,这样方便后面再次获取这个单元格来填充数据,主要就是因为合并时不能由后向前进行合并引起的。

Java代码  poi操作excel(主要为合并单元格和导出excel)_activerecord
  1. import java.io.IOException;  
  2.   
  3. import org.apache.poi.hssf.usermodel.HSSFCell;  
  4. import org.apache.poi.hssf.usermodel.HSSFCellStyle;  
  5. import org.apache.poi.hssf.usermodel.HSSFRow;  
  6. import org.apache.poi.hssf.usermodel.HSSFSheet;  
  7. import org.apache.poi.hssf.usermodel.HSSFWorkbook;  
  8. import org.apache.poi.hssf.util.Region;  
  9.   
  10.   
  11. public class ExcelTest {      
  12.      
  13.     /**    
  14.      * @param args    
  15.      */     
  16.     public static void main(String[] args) throws IOException {      
  17.      
  18.         try {      
  19.             HSSFWorkbook wb = new HSSFWorkbook();      
  20.             HSSFSheet sheet = wb.createSheet("new   sheet");      
  21.             HSSFCellStyle style = wb.createCellStyle(); // 样式对象      
  22.      
  23.             style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);// 垂直      
  24.             style.setAlignment(HSSFCellStyle.ALIGN_CENTER);// 水平      
  25.             HSSFRow row = sheet.createRow((short0);      
  26.             HSSFRow row2 = sheet.createRow((short1);      
  27.      
  28.             sheet.addMergedRegion(new Region(0, (short01, (short0));      
  29.             HSSFCell ce = row.createCell((short0);      
  30.             ce.setEncoding(HSSFCell.ENCODING_UTF_16);// 中文处理      
  31.             ce.setCellValue("项目\\日期"); // 表格的第一行第一列显示的数据      
  32.             ce.setCellStyle(style); // 样式,居中      
  33.             int num = 0;      
  34.             for (int i = 0; i < 9; i++) { // 循环9次,每一次都要跨单元格显示      
  35.                 // 计算从那个单元格跨到那一格      
  36.                 int celln = 0;      
  37.                 int celle = 0;      
  38.                 if (i == 0) {      
  39.                     celln = 0;      
  40.                     celle = 1;      
  41.                 } else {      
  42.                     celln = (i * 2);      
  43.                     celle = (i * 2 + 1);      
  44.                 }      
  45.                 // 单元格合并      
  46.                 // 四个参数分别是:起始行,起始列,结束行,结束列      
  47.                 sheet.addMergedRegion(new Region(0, (short) (celln + 1), 0,      
  48.                         (short) (celle + 1)));      
  49.                 HSSFCell cell = row.createCell((short) (celln + 1));      
  50.                 cell.setCellValue("merging" + i); // 跨单元格显示的数据      
  51.                 cell.setCellStyle(style); // 样式      
  52.                 // 不跨单元格显示的数据,如:分两行,上一行分别两格为一格,下一行就为两格,“数量”,“金额”      
  53.                 HSSFCell cell1 = row2.createCell((short) celle);      
  54.                 HSSFCell cell2 = row2.createCell((short) (celle + 1));      
  55.                 cell1.setEncoding(HSSFCell.ENCODING_UTF_16);      
  56.                 cell1.setCellValue("数量");      
  57.                 cell1.setCellStyle(style);      
  58.                 cell2.setEncoding(HSSFCell.ENCODING_UTF_16);      
  59.                 cell2.setCellValue("金额");      
  60.                 cell2.setCellStyle(style);      
  61.                 num++;      
  62.             }      
  63.      
  64.             // 在后面加上合计百分比      
  65.      
  66.             // 合计 在最后加上,还要跨一个单元格      
  67.             sheet.addMergedRegion(new Region(0, (short) (2 * num + 1), 0,      
  68.                     (short) (2 * num + 2)));      
  69.             HSSFCell cell = row.createCell((short) (2 * num + 1));      
  70.             cell.setEncoding(HSSFCell.ENCODING_UTF_16);      
  71.             cell.setCellValue("合计");      
  72.             cell.setCellStyle(style);      
  73.             HSSFCell cell1 = row2.createCell((short) (2 * num + 1));      
  74.             HSSFCell cell2 = row2.createCell((short) (2 * num + 2));      
  75.             cell1.setEncoding(HSSFCell.ENCODING_UTF_16);      
  76.             cell1.setCellValue("数量");      
  77.             cell1.setCellStyle(style);      
  78.             cell2.setEncoding(HSSFCell.ENCODING_UTF_16);      
  79.             cell2.setCellValue("金额");      
  80.             cell2.setCellStyle(style);      
  81.      
  82.             // 百分比 同上      
  83.             sheet.addMergedRegion(new Region(0, (short) (2 * num + 3), 0,      
  84.                     (short) (2 * num + 4)));      
  85.             HSSFCell cellb = row.createCell((short) (2 * num + 3));      
  86.             cellb.setEncoding(HSSFCell.ENCODING_UTF_16);      
  87.              
  88.             cellb.setCellValue("百分比");      
  89.             cellb.setCellStyle(style);      
  90.               
  91.             HSSFCell cellb1 = row2.createCell((short) (2 * num + 3));      
  92.             HSSFCell cellb2 = row2.createCell((short) (2 * num + 4));      
  93.             cellb1.setEncoding(HSSFCell.ENCODING_UTF_16);      
  94.             cellb1.setCellValue("数量");      
  95.             cellb1.setCellStyle(style);      
  96.             cellb2.setEncoding(HSSFCell.ENCODING_UTF_16);      
  97.             cellb2.setCellValue("金额");      
  98.             cellb2.setCellStyle(style);      
  99.      
  100.             /***这里是问题的关键,将这个工作簿写入到一个流中就可以输出相应的名字,这里需要写路径就ok了。 
  101.             FileOutputStream fileOut = new FileOutputStream("workbook.xls");     
  102.             wb.write(fileOut);     
  103.             fileOut.close(); 
  104.              **/  
  105.               
  106.               
  107.             /**第二种是输出到也面中的excel名称 
  108.              * pName="栏目统计表";    
  109.     response.reset();    
  110.     response.setContentType("application/x-msdownload");    
  111.     response.setHeader("Content-Disposition","attachment; filename="+new String(pName.getBytes("gb2312"),"ISO-8859-1")+".xls");    
  112.     ServletOutputStream outStream=null;    
  113.    
  114.     try{    
  115.         outStream = response.getOutputStream();    
  116.         wb.write(outStream);    
  117.     }catch(Exception e)    
  118.     {    
  119.      e.printStackTrace();    
  120.     }finally{    
  121.         outStream.close();    
  122.     }    
  123.              * */  
  124.             System.out.print("OK");      
  125.         } catch (Exception ex) {      
  126.             ex.printStackTrace();      
  127.         }      
  128.      
  129.     }      
  130.      
  131. }  

       以上就是poi对excel的基本操作。这里主要介绍的是合并单元格和导出excel。