本文演示SpringBoot整合EasyExcel，并导出数据。
一、项目搭建
    新建一个SpringBoot项目，引入依赖：
    <properties>
        <java.version>1.8</java.version>
        <easyexcel.version>2.2.6</easyexcel.version>
        <lombok.version>1.16.10</lombok.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--swagger配置-->
        <dependency>
            <groupId>com.spring4all</groupId>
            <artifactId>swagger-spring-boot-starter</artifactId>
            <version>1.8.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
        </dependency>
        <!-- lombok配置 -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${lombok.version}</version>
        </dependency>
        <!-- EasyExcel配置 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>easyexcel</artifactId>
            <version>${easyexcel.version}</version>
        </dependency>
    </dependencies>
    
二、配置文件
    配置项目端口号：
server:
  port: 8899
    
三、配置类
①Swagger配置类

@Configuration
@EnableSwagger2
public class Swagger2Configure {
    @Bean
    public Docket createRestApi() {
        return new Docket(DocumentationType.SWAGGER_2).apiInfo(apiInfo()).select()
                .apis(RequestHandlerSelectors.basePackage("com.example.demo.controller"))
                .paths(PathSelectors.any()).build();
    }

    /**
    定义展示的信息，例如标题、描述、版本等
     */
private ApiInfo apiInfo() {
        return new ApiInfoBuilder().title("api文档")
                .version("1.0").build();
    }
}

②EasyExcel工具类

public class ExcelUtils {
    public static void download(HttpServletResponse response, String fileName,String sheetName,Class cls, List data) throws IOException {
        response.setContentType("application/vnd.ms-excel");
        response.setCharacterEncoding("utf-8");
        String fname = URLEncoder.encode(fileName, "utf-8");
        response.setHeader("Content-disposition","attachment;filename=" + fname + ExcelTypeEnum.XLSX.getValue());
        LongestMatchColumnWidthStyleStrategy longestMatchColumnWidthStyleStrategy = new LongestMatchColumnWidthStyleStrategy();
        EasyExcel.write(response.getOutputStream(), cls)
                .sheet(sheetName)
                .registerWriteHandler(longestMatchColumnWidthStyleStrategy)
                .doWrite(data);
        response.flushBuffer();
    }
}

③数据实体类

@Data
public class Student {

    @ExcelProperty(value = {"编号"}, index = 0)
    private Integer id;
    @ExcelProperty(value = {"姓名"}, index = 1)
    private String name;
    @ExcelProperty(value = {"年龄"}, index = 2)
    private Integer age;

    public Student(Integer id, String name, Integer age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }
}
    
四、编码实现
    ①编写Controller类及测试请求方法：
@Api(tags = "demo测试")
@RestController
@RequestMapping("/")
public class TestController {

    @PostMapping("export")
    @ApiOperation("导出学生数据")
    public void export(HttpServletResponse response) {

        List<Student> data = buildData();
        try {
            ExcelUtils.download(response, "StudentInfo", "Test", Student.class, data);
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }

    public static List<Student> buildData(){
        List<Student> data = new ArrayList<>();
        for (int i = 1; i < 51; i++) {
            data.add(new Student(i,"学生"+i,i));
        }
        return data;
    }
}

    ②启动类
@SpringBootApplication
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

}
    ③启动项目并访问http://localhost:8989/swagger-ui.html：

下载文件后验证：

测试验证OK。