【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。