Java语言：使用EasyPOI导出文件

1、pom.xml中导入依赖包

springboot项目在pom.xml中导入依赖，maven进行更新，加载jar包。

        
            cn.afterturn
            easypoi-base
            3.0.3
        
        
            cn.afterturn
            easypoi-web
            3.0.3
        
        
            cn.afterturn
            easypoi-annotation
            3.0.3
        

 2、实体类中，在需要导出的成员变量上方加@Excel注解

package com.domain;

import cn.afterturn.easypoi.excel.annotation.Excel;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import java.io.Serializable;
import lombok.Data;

/**
 * 
 * @TableName person
 */
@TableName(value ="person")
@Data
public class Person implements Serializable {
    /**
     * 主键
     */
    @TableId(type = IdType.AUTO)
    @Excel(name="主键")
    private Long id;

    /**
     * 名字
     */
    @Excel(name="姓名")
    private String name;

    /**
     * 性别
     */
    @Excel(name="性别")
    private String sex;

    /**
     * 地址
     */
    private String adress;

    @TableField(exist = false)
    private static final long serialVersionUID = 1L;
}

 3、添加配置类（工具类）

public class ExcelUtil {
    /**
     * 导出： 常用导出模板
     */
    public static void exportExcel(List list, String title, String sheetName, Class pojoClass, String fileName, HttpServletResponse response) {
        defaultExport(list, pojoClass, fileName, response, new ExportParams(title, sheetName));
    }

    /**
     * 导出：创建表头的模板
     */
    public static void exportExcel(List list, String title, String sheetName, Class pojoClass, String fileName, boolean isCreateHeader, HttpServletResponse response) {
        ExportParams exportParams = new ExportParams(title, sheetName);
        exportParams.setCreateHeadRows(isCreateHeader);
        defaultExport(list, pojoClass, fileName, response, exportParams);
    }

    /**
     * 使用Map作为参数导出  不推荐使用
     */
    public static void exportExcel(List> list, String fileName, HttpServletResponse response) {
        defaultExport(list, fileName, response);
    }

    private static void defaultExport(List list, Class pojoClass, String fileName, HttpServletResponse response, ExportParams exportParams) {
        Workbook workbook = ExcelExportUtil.exportExcel(exportParams, pojoClass, list);
        downLoadExcel(fileName, response, workbook);
    }
    private static void defaultExport(List> list, String fileName, HttpServletResponse response) {
        Workbook workbook = ExcelExportUtil.exportExcel(list, ExcelType.HSSF);
        downLoadExcel(fileName, response, workbook);
    }
    private static void downLoadExcel(String fileName, HttpServletResponse response, Workbook workbook) {
        try {
            response.setCharacterEncoding("UTF-8");
            response.setHeader("content-Type", "application/vnd.ms-excel");
            response.setHeader("Content-Disposition",
                    "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8"));
            workbook.write(response.getOutputStream());
        } catch (IOException e) {
            throw new RuntimeException(e.getMessage());
        }
    }


    /**
     * 导入： 常用导入模板
     * @param titleRows 标题行数
     * @param headerRows 表头行数
     */
    public static  List importExcel(MultipartFile file, Integer titleRows, Integer headerRows, Class pojoClass) {
        if (file == null) {
            return null;
        }
        ImportParams params = new ImportParams();
        params.setTitleRows(titleRows);
        params.setHeadRows(headerRows);
        List list = null;
        try {
            list = ExcelImportUtil.importExcel(file.getInputStream(), pojoClass, params);
        } catch (NoSuchElementException e) {
            e.printStackTrace();
            throw new RuntimeException("excel文件不能为空");
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e.getMessage());
        }
        return list;
    }
    /**
     * excel 导入 默认 1行标题 1行表头
     */
    public static  List importExcel(MultipartFile file, Class pojoClass) throws IOException {
        return importExcel(file, 1, 1, pojoClass);
    }

    public static  List importExcel(String filePath, Integer titleRows, Integer headerRows, Class pojoClass) {
        if (StringUtils.isBlank(filePath)) {
            return null;
        }
        ImportParams params = new ImportParams();
        params.setTitleRows(titleRows);
        params.setHeadRows(headerRows);
        List list = null;
        try {
            list = ExcelImportUtil.importExcel(new File(filePath), pojoClass, params);
        } catch (NoSuchElementException e) {
            throw new RuntimeException("模板不能为空");
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e.getMessage());
        }
        return list;
    }
}

4、控制层写方法并调用工具类中的方法

@RestController
@RequestMapping("person")
public class PersonController {
    @Autowired
    PersonMapper personMapper;
    @RequestMapping("excel")
    public boolean excel(HttpServletResponse response){
        List list = personMapper.selectList(null);
        ExcelUtil.exportExcel(list,"标题","标签",Person.class,"Person.xls",response);
        return true;
    }

HttpServletResponse response 是Java的核心接口，前后台的交互模式是请求回应式的。前端向后台发请求，会被后台封装成一个请求对象。后台把数据响应给前端，就会有一个响应对象 response

5、使用网页测试

 弹窗—>保存文件—>Excel

6、导出Excel文件