Pomxml
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>3.9</version>
</dependency>
</dependencies>application.properties
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.url=jdbc:mysql://localhost:3306/cn?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT%2B8&useSSL=false
spring.datasource.driver-class-name=com.mysql.cj.jdbc.DriverPoIExcelUtils
package com.hc.controller;
import com.hc.model.User;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.util.CellRangeAddress;
//import org.slf4j.Logger;
//import org.slf4j.LoggerFactory;
import java.io.*;
//import java.lang.reflect.Method;
//import java.text.SimpleDateFormat;
//import java.util.Date;
import java.util.ArrayList;
import java.util.List;
//import java.util.Map;
//import java.util.UUID;
public final class PoIExcelUtils {
// private static Logger log = LoggerFactory.getLogger(Obj2ExcelUtils.class);
// private static final String LOGPRE = "Obj2ExcelUtils:";
/***
* 构造方法
*/
private PoIExcelUtils() {
}
/***
* 工作簿
*/
private static HSSFWorkbook workbook;
/***
* sheet
*/
private static HSSFSheet sheet;
/***
* 标题行开始位置
*/
private static final int TITLE_START_POSITION = 1;
/***
* 时间行开始位置
*/
// private static final int DATEHEAD_START_POSITION = 1;
/***
* 表头行开始位置
*/
private static final int HEAD_START_POSITION = 0;//从0行开始
/***
* 文本行开始位置
*/
private static final int CONTENT_START_POSITION = 1;//报表从第一行开始
// /**
// * @param //dataList 对象集合
// * @param //titleMap 表头信息（对象属性名称->要显示的标题值)[按顺序添加]
// * @param //sheetName sheet名称和表头值
// */
/**
* @param dataList
*/
public static void excelExport(List<User> dataList) {
// 初始化
List<String> titleMap = new ArrayList<>();
titleMap.add("编号");
titleMap.add("名称");
titleMap.add("日期");
titleMap.add("说明");
String sheetName = "用户信息";
// 初始化workbook
initHSSFWorkbook(sheetName);
// 标题行
createTitleRow(titleMap, sheetName);//userSize 对象几个属性
// 时间行
// createDateHeadRow(titleMap);
// 表头行
createHeadRow(titleMap);
// 文本行
createContentRow(dataList, titleMap.size());
//设置自动伸缩
// autoSizeColumn(titleMap.size());
// 写入处理结果
try {
//生成UUID文件名称
// UUID uuid = UUID.randomUUID();
String fileDisplay = System.currentTimeMillis() + ".xls";
//如果web项目，1、设置下载框的弹出（设置response相关参数)；
// 2、通过httpServletResponse.getOutputStream()获取
OutputStream out = new FileOutputStream("D:\\" + fileDisplay);
workbook.write(out);
out.close();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* web项目下载
*
// * @param dataList 对象集合
// * @param titleMap 表头信息（对象属性名称->要显示的标题值)[按顺序添加]
// * @param sheetName sheet名称和表头值
*/
// public static InputStream excelExportWeb(List<?> dataList, Map<String, String> titleMap,
// String sheetName) {
// // 初始化workbook
// initHSSFWorkbook(sheetName);
// // 标题行
// createTitleRow(titleMap, sheetName);
// // 时间行
//// createDateHeadRow(titleMap);
// // 表头行
// createHeadRow(titleMap);
// // 文本行
// createContentRow(dataList, titleMap);
// //设置自动伸缩
//// autoSizeColumn(titleMap.size());
// // 写入处理结果
// ByteArrayOutputStream os = null;
// try {
// if (workbook == null) {
//// log.error(LOGPRE + "HSSFWorkbook为空");
// return null;
// }
// // 将文件存到流中
// os = new ByteArrayOutputStream();
// workbook.write(os);
// byte[] fileContent = os.toByteArray();
// return new ByteArrayInputStream(fileContent);
// } catch (Exception e) {
// e.printStackTrace();
// } finally {
// if (os != null) {
// try {
// os.close();
// } catch (IOException e) {
//// log.error(LOGPRE + e.getMessage(), e);
// }
// }
// if (workbook != null) {
// try {
//// workbook.close();
// } catch (Exception e) {
//// log.error(LOGPRE + e.getMessage(), e);
// }
// }
// // log.info("导出结束时间："+new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").
// format(new Date(System.currentTimeMillis())));
// }
// return null;
// }
/***
*
// * @param sheetName
* sheetName
*/
private static void initHSSFWorkbook(String sheetName) {
workbook = new HSSFWorkbook();
sheet = workbook.createSheet(sheetName);
}
/**
* 生成标题（第零行创建）
* <p>
* // * @param titleMap 对象属性名称->表头显示名称
* // * @param sheetName sheet名称
*/
// firstCol---3 userSize-1
private static void createTitleRow(List<String> titleMap, String sheetName) {//5 对象属性
CellRangeAddress titleRange = new CellRangeAddress(1, 1,
titleMap.size() - 1, titleMap.size() - 1);
sheet.addMergedRegion(titleRange);
HSSFRow titleRow = sheet.createRow(TITLE_START_POSITION);
HSSFCell titleCell = titleRow.createCell(0);
titleCell.setCellValue(sheetName);
}
/**
* 创建时间行（第一行创建）
*
// * @param titleMap 对象属性名称->表头显示名称
*/
// firstCol---3
/* private static void createDateHeadRow(Map<String, String> titleMap) {
CellRangeAddress dateRange = new CellRangeAddress(1, 1, 1, titleMap.size() - 1);
sheet.addMergedRegion(dateRange);
HSSFRow dateRow = sheet.createRow(DATEHEAD_START_POSITION);
HSSFCell dateCell = dateRow.createCell(0);
dateCell.setCellValue(new SimpleDateFormat("yyyy年MM月dd日").format(new Date()));
}*/
/**
* 创建表头行（第二行创建）
* <p>
* // * @param titleMap 对象属性名称->表头显示名称
*/
private static void createHeadRow(List<String> titleMap) {
// 第2行创建
HSSFRow headRow = sheet.createRow(HEAD_START_POSITION);
//不加标题和时间行，第0行创建
// HSSFRow headRow = sheet.createRow(0);
int i = 0;
for (String entry : titleMap) {
HSSFCell headCell = headRow.createCell(i);
headCell.setCellValue(entry);
i++;
}
}
/**
* // * @param dataList 对象数据集合
*
* @param //tit//leMap 表头信息
*/
private static void createContentRow(List<User> dataList, int titleSize) {
try {
int i = 0;
for (User obj : dataList) {
HSSFRow textRow = sheet.createRow(CONTENT_START_POSITION + i);
//自定义列段
for (int i1 = 0; i1 < titleSize; i1++) {
HSSFCell textcell = textRow.createCell(i1);
if (i1 == 0) {
textcell.setCellValue(obj.getUserId());
} else if (i1 == 1) {
textcell.setCellValue(obj.getUserName());
} else if (i1 == 2) {
textcell.setCellValue(obj.getUserDay());
} else if (i1 == 3) {
textcell.setCellValue(obj.getUserBase());
}
}
// 不加标题和时间行，第1行创建
// HSSFRow textRow = sheet.createRow(1 + i);
// int j = 0;
// for (String entry : titleMap.keySet()) {
// String method = "get" + entry.substring(0, 1).
// toUpperCase() + entry.substring(1);
// Method m = obj.getClass().getMethod(method, null);
// String value = m.invoke(obj, null).toString();
// HSSFCell textcell = textRow.createCell(j);
// textcell.setCellValue(value);
// j++;
// }
i++;
}
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 自动伸缩列（如非必要，请勿打开此方法，耗内存）
*
// * @param size 列数
*/
// private static void autoSizeColumn(Integer size) {
// for (int j = 0; j < size; j++) {
// sheet.autoSizeColumn(j);
// }
// }
}
User
package com.hc.model;
public class User {
private int userId;
private String userName;
private String userDay;
private String userBase;
public User() {
}
public User(String userName, String userDay, String userBase) {
this.userName = userName;
this.userDay = userDay;
this.userBase = userBase;
}
public int getUserId() {
return userId;
}
public void setUserId(int userId) {
this.userId = userId;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getUserDay() {
return userDay;
}
public void setUserDay(String userDay) {
this.userDay = userDay;
}
public String getUserBase() {
return userBase;
}
public void setUserBase(String userBase) {
this.userBase = userBase;
}
}
UserMapper
package com.hc.mapper;
import com.hc.model.User;
import org.apache.ibatis.annotations.Select;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public interface UserMapper {
@Select("select * from User")
List<User> allUser();
}
UserService
package com.hc.service;
import com.hc.model.User;
import java.util.List;
public interface UserService {
List<User> allUser();
}
UserServiceImpl
package com.hc.service.impl;
import com.hc.mapper.UserMapper;
import com.hc.model.User;
import com.hc.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class UserServiceImpl implements UserService {
@Autowired
private UserMapper userMapper;
@Override
public List<User> allUser() {
return userMapper.allUser();
}
}
UserController
package com.hc.controller;
import com.hc.model.User;
import com.hc.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import java.util.List;
@Controller
public class UserController {
@Autowired
private UserService userService;
@RequestMapping("data")
@ResponseBody
public String PoIData() {
List<User> staffs = userService.allUser();
PoIExcelUtils.excelExport(staffs);
return "yes";
}
}
DatapoiApplication
package com.hc;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.hc.mapper")
public class DatapoiApplication {
public static void main(String[] args) {
SpringApplication.run(DatapoiApplication.class, args);
}
}
Pol数据导出