【POI】修改Excel内容

 package com.what21.test;

 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;

 import org.apache.poi.hssf.usermodel.HSSFCell;
 import org.apache.poi.hssf.usermodel.HSSFRow;
 import org.apache.poi.hssf.usermodel.HSSFSheet;
 import org.apache.poi.hssf.usermodel.HSSFWorkbook;
 import org.apache.poi.xssf.usermodel.XSSFCell;
 import org.apache.poi.xssf.usermodel.XSSFSheet;
 import org.apache.poi.xssf.usermodel.XSSFWorkbook;

 public class TestPoi {
     public static void updateExcel(File exlFile, String sheetName, int col,
             int row, String value) throws Exception {
         FileInputStream fis = new FileInputStream(exlFile);
         HSSFWorkbook workbook = new HSSFWorkbook(fis);
         // workbook.
         HSSFSheet sheet = workbook.getSheet(sheetName);
         HSSFCell mycell = sheet.createRow(row).createCell(col);
         mycell.setCellValue(value);
         HSSFRow r = sheet.getRow(row);
         HSSFCell cell = r.getCell(col);
         // int type=cell.getCellType();
         String str1 = cell.getStringCellValue();
         // 这里假设对应单元格原来的类型也是String类型
         cell.setCellValue(value);
         System.out.println("单元格原来值为" + str1);
         System.out.println("单元格值被更新为" + value);

         fis.close();// 关闭文件输入流

         FileOutputStream fos = new FileOutputStream(exlFile);
         workbook.write(fos);
         fos.close();// 关闭文件输出流
     }

     public static void update2(String url) {
         int coloum = 2; // 比如你要获取第1列
         try {
             HSSFWorkbook workbook = new HSSFWorkbook(new FileInputStream(url));
             HSSFSheet sheet = workbook.getSheet("Sheet1");

             for (int i = 0; i <= sheet.getLastRowNum(); i++) {
                 HSSFRow row = sheet.getRow((short) i);
                 if (null == row) {
                     continue;
                 } else {
                     HSSFCell cell = row.getCell((short) coloum);
                     if (null == cell) {
                         continue;
                     } else {

                         cell.setCellValue("he1");
                     }
                 }
             }
             FileOutputStream out = null;
             try {
                 out = new FileOutputStream(url);
                 workbook.write(out);
             } catch (IOException e) {
                 e.printStackTrace();
             } finally {
                 try {
                     out.close();
                 } catch (IOException e) {
                     e.printStackTrace();
                 }
             }
         } catch (FileNotFoundException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }
     }

     public static boolean writeXlsx(String fileName, int row, int column,
             String content) {
         boolean flag = false;
         FileOutputStream out = null;
         XSSFWorkbook xwb;
         try {
             xwb = new XSSFWorkbook(new FileInputStream(fileName));
             XSSFSheet xSheet = xwb.getSheetAt(0);
             XSSFCell xCell = xSheet.createRow(row).createCell(column);
             xCell.setCellValue(content);
             out = new FileOutputStream(fileName);
             xwb.write(out);
             out.close();
             flag = true;
         } catch (IOException e) {
             e.printStackTrace();
         } catch (RuntimeException e) {
             e.printStackTrace();
         }
         return flag;
     }

     public static void main(String[] args) throws Exception {
         // TODO Auto-generated method stub
         // 下面改成你自己的xls文件进行测试，2003格式的，不能2007
         File file = new File("C:\\Users\\Administrator\\Desktop\\test.xls");
         // 下面尝试更改第一行第一列的单元格的值
         updateExcel(file, "Sheet1", 0, 0, "hehe");
         update2("C:\\Users\\Administrator\\Desktop\\test.xls");
         File file1 = new File(
                 "C:\\Users\\Administrator\\Desktop\\test - 副本.xlsx");
         writeXlsx("C:\\Users\\Administrator\\Desktop\\test - 副本.xlsx", 0, 0,
                 "1");
     }
 }

　　注意事项：如果修改的坐标对应的单元格是空，会报错。

　　建议这么写：

　　HSSFCell mycell = sheet.createRow(row).createCell(col);
　　mycell.setCellValue(value);

　　这样写有一个问题：如果定位错误，会带来不必要的麻烦。

　　通常在生成原始Excel时，最好能对空单元格赋空（强制添加空字符串），这样在使用SAXPOI或者SAX解析较大文本的Excel的时候，可以

有效的避免因为空单元格而导致列数据错位的问题。

　　上面的代码是很常见的，在网上能找到一堆。根据不同的场景可以传入一组需要修改的坐标，通过循环来修改。这样可以减少打开文件的次数，提高

效率。