引入jar

 <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>easyexcel</artifactId>
            <version>3.1.0</version>
        </dependency>

代码

    public static void main(String[] args) {
        //选择存储地址
        String fileName = "/Users/qweasdzxc/Downloads/text.xlsx";

        // 创建ExcelWriterBuilder对象
        ExcelWriter excelWriter = EasyExcelFactory.write(fileName).build();

        //设置动态表头
        List<List<String>> head1 =new ArrayList<>();
        head1.add(Collections.singletonList("姓名"));
        head1.add(Collections.singletonList("年龄"));
        head1.add(Collections.singletonList("性别"));

        //填充数据
        List<List<Object>> data1 = new ArrayList<>();
        data1.add(Arrays.asList("张三", 20, "男"));
        data1.add(Arrays.asList("李四", 25, "女"));

        //放入sheet1中
        //automaticMergeHead 控制是否合并相同标题的单元格 false==不合并
        WriteSheet writeSheet = EasyExcelFactory.writerSheet(0, "学生信息1").head(head1).automaticMergeHead(false).build();
        excelWriter.write(data1, writeSheet);


        List<List<String>> head2 =new ArrayList<>();
        head2.add(Collections.singletonList("学科"));
        head2.add(Collections.singletonList("分数"));

        List<List<Object>> data2 = new ArrayList<>();
        data2.add(Arrays.asList("数学", 90));
        data2.add(Arrays.asList("英语", 85));

        //放入sheet2中
        writeSheet = EasyExcelFactory.writerSheet(1, "学生信息2").head(head2).build();
        excelWriter.write(data2, writeSheet);
        //关流
        excelWriter.finish();

    }

效果