Java使用Apache.POI中HSSFWorkbook导出到Excel的实现方法

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

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 + '/'' +    '}'; }}

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();  } }}

@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(); }