第一步：所需要的jar包

 第二步：上代码

package cn.lystudio.poi.excel;

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

import org.apache.commons.io.FileUtils;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;


/**
 * 生成excel文件
 * @author Administrator
 *
 */
public class PoiCExcel2 {
	
	public static void main(String[] args) {
		//创建一个数组，存放数据
		String[] title = {"id","name","sex"};
		
		//创建excel工作蒲
		XSSFWorkbook workbook = new XSSFWorkbook();
		
		//创建一个工作表sheet
		Sheet sheet = workbook.createSheet();
		//创建第一行
		Row row = sheet.createRow(0);
		//定义cell
		Cell cell = null;
		
		//插入第一行数据，id,name,sex
		for ( int i =0; i<title.length;i++) {
			cell = row.createCell(i);
			cell.setCellValue(title[i]);
		}
		//追加数据
		for ( int i =1; i<10;i++) {
			Row nextrow =sheet.createRow(i);
			Cell cell2  = nextrow.createCell(0);
			cell2.setCellValue("a"+i);
			
			cell2 = nextrow.createCell(1);
			cell2.setCellValue("user"+i);
			
			cell2 = nextrow.createCell(2);
			cell2.setCellValue("女生");
		}
		//创建一个文件
		File file = new File("D:/poi_test.xlsx");
		try {
			file.createNewFile();
			//将excel内容存盘
			FileOutputStream stream = FileUtils.openOutputStream(file);
			workbook.write(stream);
			stream.close();
		} catch (IOException e) {
			
			e.printStackTrace();
		}
	}
}