[Java知识库]java导出excel文件

所需工具

采用alibaba的EasyExcel， EasyExcel是一个基于Java的简单、省内存的读写Excel的开源项目。在尽可能节约内存的情况下支持读写百M的Excel。
因为我目前用Maven来管理包，所以附上Maven导包代码

        <!--excel导出-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>easyexcel</artifactId>
            <version>1.1.2-beat1</version>
        </dependency>

生成表头

我采用在实体类写注解的方式生成表头，此处用医生的实体类来做演示，此处getter和setter方法不再赘述。需要注意两个点
1.@ExcelProperty(value,index)，其中value为列头名称，index为索引
2.需使该实体类继承BaseRowModel类

public class HDoctor extends BaseRowModel {
    @ExcelProperty(value = "编号",index = 0)
    private Integer d_id;

    @ExcelProperty(value = "姓名",index = 0)
    private String d_name;

    @ExcelProperty(value = "身份证号",index = 0)
    private String d_idCard;

    @ExcelProperty(value = "手机号码",index = 0)
    private String d_phone;

    @ExcelProperty(value = "性别",index = 0)
    private Integer d_sex;

    @ExcelProperty(value = "年龄",index = 0)
    private Integer d_age;

    @ExcelProperty(value = "科室",index = 0)
    private Integer d_keshi;

    @ExcelProperty(value = "学历",index = 0)
    private Integer d_xueli;

    @ExcelProperty(value = "个人简介",index = 0)
    private String d_desc;
    }

生成数据

因为我在写的是一个SSM项目，所以数据的导出写在Service层
此处需要注意
1.FileOutputStream()中写的是所生成.xlsx文件所在位置，我这里是直接输出到了桌面
2.Sheet sheet1 = new Sheet(1, 0, HDoctor.class);中第三个参数为实体类的类型，即继承了BaseRowModel类的那个类的名字。
3.输入数据格式为list

@Transactional(propagation = Propagation.REQUIRED,rollbackFor = {Exception.class})
    public void ToExcel(Integer[] ids){
        List<HDoctor> list = new ArrayList<>();
        for (Integer id : ids) {
            System.out.println(id);
            HDoctor doctor = doctorMapper.selectByPrimaryKey(id);
            list.add(doctor);
        }
        try (OutputStream out = new FileOutputStream("C:\\Users\\Cave\\Desktop\\Doctors.xlsx");) {
            ExcelWriter writer = new ExcelWriter(out, ExcelTypeEnum.XLSX);
            Sheet sheet1 = new Sheet(1, 0, HDoctor.class);
            sheet1.setSheetName("sheet1");
            writer.write(list, sheet1);
            writer.finish();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

生成结果