使用Apache.POI中HSSFWorkbook导出到Excel

使用Apache.POI中HSSFWorkbook导出到Excel

1.引入Poi依赖（3.12）

依赖如下：

<dependency>
     <groupId>org.apache.poi</groupId>
     <artifactId>poi</artifactId>
     <version>3.12</version>
</dependency>

2.创建实体类（User.java）

package com.kd.nm.entity.pojo;

/**
 * 实体类（User）
 *
 * author 小辰哥哥
 */
public class User {
     
  // 用户编号
  private String userNo;
  // 用户名称
  private String userName;
  // 年龄
  private String age;

  // 无参构造
  public User() {
     
  }

  // 有参构造
  public User(String userNo, String userName, String age) {
     
    this.userNo = userNo;
    this.userName = userName;
    this.age = age;
  }

  // get与set方法进行封装
  public String getUserNo() {
     
    return userNo;
  }

  public void setUserNo(String userNo) {
     
    this.userNo = userNo;
  }

  public String getUserName() {
     
    return userName;
  }

  public void setUserName(String userName) {
     
    this.userName = userName;
  }

  public String getAge() {
     
    return age;
  }

  public void setAge(String age) {
     
    this.age = age;
  }

  // 重新toString方法
  @Override
  public String toString() {
     
    return "User{" +
        "userNo='" + userNo + '\'' +
        ", userName='" + userName + '\'' +
        ", age='" + age + '\'' +
        '}';
  }
}

3.Excel相关工具类（ExcelUtil、ReflectUtil）

package com.kd.nm.util;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.apache.poi.hssf.usermodel.*;

/**
 *  Description : Excel相关工具类
 *
 * @author:  小辰哥哥
 *
 */
public class ExcelUtil {
     

  /**
   * 生成excel表格
   * @param heads 表头内容
   * @param data  数据内容
   * @return
   */
  public static HSSFWorkbook creatExcel(Map<String, String> heads, List data) {
     

    // 声明一个工作薄
    HSSFWorkbook workbook = new HSSFWorkbook();
    // 生成一个表格
    HSSFSheet sheet = workbook.createSheet();

    // 生成标题行样式
    HSSFCellStyle headStyle = creatStyle(workbook, (short) 14);

    // 生成表格内容样式
    HSSFCellStyle bodyStyle = creatStyle(workbook, (short) 10);

    // 标题元素
    List<String> keys = new ArrayList<String>(heads.keySet());

    // 像素单位
    short px = 1000;
    // 设置列宽
    for (int columnIndex = 0; columnIndex < keys.size(); columnIndex++) {
     

      sheet.setColumnWidth(columnIndex, 6 * px);
    }

    // 生成表格
    for (int rowNum = 0; rowNum <= data.size(); rowNum++) {
     

      // 创建行
      HSSFRow row = sheet.createRow(rowNum);

      for (int cellNum = 0; cellNum < keys.size(); cellNum++) {
     

        // 创建列
        HSSFCell cell = row.createCell(cellNum);

        // 标题
        if (rowNum == 0) {
     

          cell.setCellStyle(headStyle);
          cell.setCellValue(heads.get(keys.get(cellNum)));
        } else {
      // 内容

          cell.setCellStyle(bodyStyle);
          // 通过反射获取
          cell.setCellValue(ReflectUtil.getValue(keys.get(cellNum), data.get(rowNum - 1)));
        }
      }
    }

    return workbook;
  }

  /**
   * 生成样式
   * @param workbook
   * @param size
   * @return
   */
  public static HSSFCellStyle creatStyle(HSSFWorkbook workbook, short size) {
     

    HSSFCellStyle style = workbook.createCellStyle();
    style.setAlignment((HSSFCellStyle.ALIGN_CENTER));
    style.setVerticalAlignment((HSSFCellStyle.VERTICAL_CENTER));
    HSSFFont font = workbook.createFont();
    font.setFontHeightInPoints(size);
    font.setFontName("微软雅黑");
    style.setFont(font);
    style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
    style.setBorderTop(HSSFCellStyle.BORDER_THIN);
    style.setBorderRight(HSSFCellStyle.BORDER_THIN);
    style.setBorderLeft(HSSFCellStyle.BORDER_THIN);

    return style;
  }
}

package com.kd.nm.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.ReflectionUtils;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;

/**
 * 反射工具包
 *
 * @author:  小辰哥哥
 */
public class ReflectUtil {
     

  private static final Logger logger = LoggerFactory.getLogger(ReflectUtil.class);

  public static String getValue(String key, Object obj) {
     

    String value = "";

    try {
     

      // 获取当前属性
      PropertyDescriptor pd = new PropertyDescriptor(key, obj.getClass());
      // 获取get方法
      Method getMd = pd.getReadMethod();
      value = getMd.invoke(obj).toString();
    } catch (Exception e) {
     

      logger.error("获取内容失败！");
      e.printStackTrace();
    }

    return value;
  }

  public static void setValue(String key, String value, Object obj) {
     

    try {
     

      // 获取当前属性
      PropertyDescriptor pd = new PropertyDescriptor(key, obj.getClass());
      // 获取set方法
      Method writeMd = pd.getWriteMethod();
      writeMd.invoke(obj, value);
    } catch (Exception e) {
     

      logger.error("设置内容失败！");
      e.printStackTrace();
    }
  }
}

4.后端控制器代码

@RequestMapping(value = "/exportExcel",method = RequestMethod.GET,produces = "application/json")
  public void exportExcel(HttpServletResponse httpServletResponse) throws IOException {
     

    // 表头内容（可在前端设置，通过参数传递进来） Key是实体类的属性值，value是表头的lable
    Map<String,String> head = new HashMap<>();
    head.put("userNo","用户编号");
    head.put("userName","用户名称");
    head.put("age","年龄");

    // 表格数据内容,模拟数据库查询出来的数据
    List<User> data = new ArrayList<>();
    data.add(new User("1","小辰哥哥","18"));
    data.add(new User("2","小猪妹妹","18"));
    data.add(new User("3","大猪哥哥","18"));
    
    
    // 生成工作薄
    HSSFWorkbook hssfWorkbook = ExcelUtil.creatExcel(head, data);

    // 定义文件名
    String fileName = "导出Excel表格";

    httpServletResponse.setHeader("Cache-Control", "max-age=0");
    httpServletResponse.setContentType("application/vnd.ms-excel");
    httpServletResponse.addHeader("Content-disposition", "attachment;filename=" + new String(fileName.getBytes("gb2312"),
        "ISO-8859-1") + ".xls");

    OutputStream outputStream = httpServletResponse.getOutputStream();

    hssfWorkbook.write(outputStream);
    outputStream.flush();
    outputStream.close();
  }

5.访问映射地址

接口访问：

http://localhost:9090/FaultTreatment/api/standard/exportExcel

---

总结

每天一个提升小技巧！！！