EasyExcel

EasyExcel是一个基于Java的、快速、简洁、解决大文件内存溢出的Excel处理工具。
他能让你在不用考虑性能、内存的等因素的情况下，快速完成Excel的读、写等功能。

引入依赖

 	<dependency><groupId>com.alibaba</groupId><artifactId>easyexcel</artifactId><version>3.1.3</version> </dependency>

表结构

学生表

CREATE TABLE `student`  (`id` bigint UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '学生表ID',`sname` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '学生姓名',`sno` bigint NOT NULL COMMENT '学号',`sex` char(2) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '性别',`age` int NOT NULL COMMENT '年龄',`is_deleted` tinyint UNSIGNED NOT NULL DEFAULT 0 COMMENT '是否删除',PRIMARY KEY (`id`)
);

课程表

CREATE TABLE `course`  (`id` bigint UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '课程表ID',`cname` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '课程名',`cno` bigint NOT NULL COMMENT '课程号',`tno` bigint NOT NULL COMMENT '任教教师编码',`is_deleted` tinyint(1) UNSIGNED NOT NULL DEFAULT 0 COMMENT '是否删除',PRIMARY KEY (`id`)
);

教师表

CREATE TABLE `teacher`  (`id` bigint UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '教师表ID',`tname` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '教师姓名',`tno` bigint NOT NULL COMMENT '教师编号',`sex` char(2) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '性别',`age` int NOT NULL COMMENT '年龄',`is_deleted` tinyint(1) UNSIGNED NOT NULL DEFAULT 0 COMMENT '是否删除',PRIMARY KEY (`id`)
);

多sheet上传时已上传了部分数据，所以表中目前有数据

项目结构

下载模板实体类

StudentVo

@Data
public class StudentVo {/**学生姓名**/@ExcelProperty(value = "姓名",index = 0)private String sname;/**学号**/@ExcelProperty(value = "学号",index = 1)private Long sno;/**性别**/@ExcelProperty(value = "性别",index = 2)private String sex;/**年龄**/@ExcelProperty(value = "年龄",index = 3)private Integer age;}

CourseVo

@Data
public class CourseVo {/**课程名**/@ExcelProperty(value = "课程名",index = 0)private String cname;/**课程号**/@ExcelProperty(value = "课程号",index = 1)private Long cno;/**任教教师编号**/@ExcelProperty(value = "任教教师编号",index = 2)private Long tno;
}

TeacherVo

@Data
public class TeacherVo {/**教师姓名**/@ExcelProperty(value = "姓名", index = 0)private String tname;/**教师编号**/@ExcelProperty(value = "教师编号", index = 1)private Long tno;/**性别**/@ExcelProperty(value = "性别", index = 2)private String sex;/**年龄**/@ExcelProperty(value = "年龄", index = 3)private Integer age;
}

Controller

@RestController
@RequestMapping("/easyExcel")
public class EasyExcelController {@Resourceprivate IEasyExcelService easyExcelService;@PostMapping("excelExport")public void excelExport(HttpServletResponse response){easyExcelService.excelExport(response);}
}

Service

EasyExcelService

public interface IEasyExcelService {void excelExport(HttpServletResponse response);
}

StudentService

public interface IStudentService extends IService<Student> {
}

CourseService

public interface ICourseService extends IService<Course> {
}

TeacherService

public interface ITeacherService extends IService<Teacher> {
}

ServiceImpl

EasyExcelServiceImpl

@Service
public class EasyExcelServiceImpl implements IEasyExcelService {@Resourceprivate StudentMapper studentMapper;@Resourceprivate CourseMapper courseMapper;@Resourceprivate TeacherMapper teacherMapper;@Overridepublic void excelExport(HttpServletResponse response) {try {String fileName = "student";ExcelWriter excelWriter = EasyExcel.write(response.getOutputStream()).build();WriteSheet studentInfo = EasyExcel.writerSheet(0,"student").head(StudentVo.class).registerWriteHandler(new LongestMatchColumnWidthStyleStrategy()).build();WriteSheet courseInfo = EasyExcel.writerSheet(1,"course").head(CourseVo.class).registerWriteHandler(new LongestMatchColumnWidthStyleStrategy()).build();WriteSheet teacherInfo = EasyExcel.writerSheet(2,"teacher").head(TeacherVo.class).registerWriteHandler(new LongestMatchColumnWidthStyleStrategy()).build();List<Student> studentList = studentMapper.selectList(null);List<Course> courseList = courseMapper.selectList(null);List<Teacher> teacherList = teacherMapper.selectList(null);excelWriter.write(studentList,studentInfo);excelWriter.write(courseList,courseInfo);excelWriter.write(teacherList,teacherInfo);response.setContentType("application/vnd.ms-excel;charset=utf-8");response.setCharacterEncoding("UTF-8");response.setHeader("Content-Disposition","attachment;filename="+fileName+".xlsx");excelWriter.finish();}catch (IOException e){e.printStackTrace();}}

StudentServiceImpl

@Service
public class StudentServiceImpl extends ServiceImpl<StudentMapper, Student> implements IStudentService {
}

CourseServiceImpl

@Service
public class CourseServiceImpl extends ServiceImpl<CourseMapper, Course> implements ICourseService {
}

TeacherServiceImpl

@Service
public class TeacherServiceImpl extends ServiceImpl<TeacherMapper, Teacher> implements ITeacherService {
}

mapper

StudentMapper

public interface StudentMapper extends BaseMapper<Student> {
}

CourseMapper

public interface CourseMapper extends BaseMapper<Course> {
}

TeacherMapper

public interface TeacherMapper extends BaseMapper<Teacher> {
}

启动项目

测试

使用postman测试，测试方法如下


下载完成后，打开Excel表查看内容

操作完成