如何使用Apache POI将二维数组数据导出到Excel表格？

<dependency>
    <groupid>org.apache.poi</groupid>
    <artifactid>poi</artifactid>
    <version>3.17</version>
</dependency>
<dependency>
    <groupid>org.apache.poi</groupid>
    <artifactid>poi-ooxml</artifactid>
    <version>3.17</version>
</dependency>

xssfworkbook workbook = new xssfworkbook();
xssfsheet sheet = workbook.createsheet("worksheet");

xssfrow row = sheet.createrow(0);
for (int i = 0; i < headlist.size(); i++) {
    xssfcell cell = row.createcell(i);
    cell.setcellvalue(headlist.get(i));
}

for (int i = 0; i < contentlist.size(); i++) {
    row = sheet.createrow(i + 1);
    for (int j = 0; j < contentlist.get(i).size(); j++) {
        row.createcell(j).setcellvalue(contentlist.get(i).get(j));
    }
}

xssfworkbook workbook = new xssfworkbook();
workbook.write(new fileoutputstream(file));
workbook.close();

import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class WriteToExcel {

    public static void main(String[] args) {
        // 表头测试数据
        List<String> headList = new ArrayList<>();
        headList.add("昵称");
        headList.add("年龄");

        // 内容测试数据
        List<List<String>> contentList = getContent();

        // 创建工作簿和工作表
        XSSFWorkbook workbook = new XSSFWorkbook();
        XSSFSheet sheet = workbook.createSheet("WorkSheet");

        // 设置表头
        XSSFRow row = sheet.createRow(0);
        for (int i = 0; i < headList.size(); i++) {
            XSSFCell cell = row.createCell(i);
            cell.setCellValue(headList.get(i));
        }

        // 设置内容
        for (int i = 0; i < contentList.size(); i++) {
            row = sheet.createRow(i + 1);
            for (int j = 0; j < contentList.get(i).size(); j++) {
                row.createCell(j).setCellValue(contentList.get(i).get(j));
            }
        }

        // 保存文件
        try {
            workbook.write(new FileOutputStream("D://work.xls"));
            workbook.close();
            System.out.println("写入成功");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    protected static List<List<String>> getContent() {
        List<List<String>> contentList = new ArrayList<>();
        List<String> content1 = new ArrayList<>();
        content1.add("张三");
        content1.add("18");
        List<String> content2 = new ArrayList<>();
        content2.add("李四");
        content2.add("20");
        contentList.add(content1);
        contentList.add(content2);
        return contentList;
    }
}