SpringBoot导入导出数据实现方法详解

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2023-06-28
Java限流实现的几种方法详解
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标签   SpringBoot

今天给大家带来的是一个 SpringBoot导入导出数据

首先我们先创建项目 注意：创建SpringBoot项目时一定要联网不然会报错

项目创建好后我们首先对 application.yml 进行编译

server:
 port: 8081
# mysql
spring:
 datasource:
  driver-class-name: com.mysql.cj.jdbc.Driver
  url: jdbc:mysql://127.0.0.1:3306/dvd?characterEncoding=utf-8&&severTimezone=utc
  username: root
  password: root
 thymeleaf:
  mode: HTML5
  cache: false
  suffix: .html
  prefix: classpath:/
mybatis:
 mapperLocations: classpath:mapper/**/*.xml
 configuration:
  map-underscore-to-camel-case: true
pagehelper:
 helper-dialect: mysql
 offset-as-page-num: true
 params: count=countSql
 reasonable: true
 row-bounds-with-count: true
 support-methods-arguments: true

注意：在 ：后一定要空格，这是他的语法，不空格就会运行报错

接下来我们进行对项目的构建 创建好如下几个包 可根据自己实际需要创建其他的工具包之类的

mapper：用于存放dao层接口

pojo：用于存放实体类

service：用于存放service层接口，以及service层实现类

controller：用于存放controller控制层

接下来我们开始编写代码

首先是实体类

package com.bdqn.springbootexcel.pojo;
import lombok.Data;
import java.io.Serializable;
import java.util.List;
@Data
public class ExcelData implements Serializable{
    //文件名称
    private String fileName;
    //表头数据
    private String[] head;
    //数据
    private List<String[]> data;
}

然后是service层

package com.bdqn.springbootexcel.service;
import com.bdqn.springbootexcel.pojo.User;
import org.apache.ibatis.annotations.Select;
import javax.servlet.http.HttpServletResponse;
import java.util.List;
public interface ExcelService {
    Boolean exportExcel(HttpServletResponse response, String fileName, Integer pageNum, Integer pageSize);
    Boolean importExcel(String fileName);
    List<User> find();
}
package com.bdqn.springbootexcel.service;
import com.bdqn.springbootexcel.mapper.UserMapper;
import com.bdqn.springbootexcel.pojo.ExcelData;
import com.bdqn.springbootexcel.pojo.User;
import com.bdqn.springbootexcel.util.ExcelUtil;
import lombok.extern.slfj.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import javax.servlet.http.HttpServletResponse;
import java.util.ArrayList;
import java.util.List;
@Slfj
@Service
public class ExcelServiceImpl implements ExcelService {
    @Autowired
    private UserMapper userMapper;
    @Override
    public Boolean exportExcel(HttpServletResponse response, String fileName, Integer pageNum, Integer pageSize) {
        log.info("导出数据开始。。。。。。");
        //查询数据并赋值给ExcelData
        List<User> userList = userMapper.find();
        List<String[]> list = new ArrayList<String[]>();
        for (User user : userList) {
            String[] arrs = new String[userList.size()];
            arrs[] = String.valueOf(user.getId());
            arrs[] = String.valueOf(user.getName());
            arrs[] = String.valueOf(user.getAge());
            arrs[] = String.valueOf(user.getSex());
            list.add(arrs);
        }
        //表头赋值
        String[] head = {"序列", "名字", "年龄", "性别"};
        ExcelData data = new ExcelData();
        data.setHead(head);
        data.setData(list);
        data.setFileName(fileName);
        //实现导出
        try {
            ExcelUtil.exportExcel(response, data);
            log.info("导出数据结束。。。。。。");
            return true;
        } catch (Exception e) {
            log.info("导出数据失败。。。。。。");
            return false;
        }
    }
    @Override
    public Boolean importExcel(String fileName) {
        log.info("导入数据开始。。。。。。");
        try {
            List<Object[]> list = ExcelUtil.importExcel(fileName);
            System.out.println(list.toString());
            for (int i =; i < list.size(); i++) {
                User user = new User();
                user.setName((String) list.get(i)[]);
                user.setAge((String) list.get(i)[]);
                user.setSex((String) list.get(i)[]);
                userMapper.add(user);
            }
            log.info("导入数据结束。。。。。。");
            return true;
        } catch (Exception e) {
            log.info("导入数据失败。。。。。。");
            e.printStackTrace();
        }
        return false;
    }
    @Override
    public List<User> find() {
        return userMapper.find();
    }
}

工具类

package com.bdqn.springbootexcel.util;
import com.bdqn.springbootexcel.pojo.ExcelData;
import com.bdqn.springbootexcel.pojo.User;
import lombok.extern.slfj.Slf4j;
import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.ss.usermodel.*;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import static org.apache.poi.ss.usermodel.CellType.*;
@Slfj
public class ExcelUtil {
    public static void exportExcel(HttpServletResponse response, ExcelData data) {
        log.info("导出解析开始，fileName:{}",data.getFileName());
        try {
            //实例化HSSFWorkbook
            HSSFWorkbook workbook = new HSSFWorkbook();
            //创建一个Excel表单，参数为sheet的名字
            HSSFSheet sheet = workbook.createSheet("sheet");
            //设置表头
            setTitle(workbook, sheet, data.getHead());
            //设置单元格并赋值
            setData(sheet, data.getData());
            //设置浏览器下载
            setBrowser(response, workbook, data.getFileName());
            log.info("导出解析成功!");
        } catch (Exception e) {
            log.info("导出解析失败!");
            e.printStackTrace();
        }
    }
    private static void setTitle(HSSFWorkbook workbook, HSSFSheet sheet, String[] str) {
        try {
            HSSFRow row = sheet.createRow();
            //设置列宽，setColumnWidth的第二个参数要乘以，这个参数的单位是1/256个字符宽度
            for (int i =; i <= str.length; i++) {
                sheet.setColumnWidth(i, * 256);
            }
            //设置为居中加粗,格式化时间格式
            HSSFCellStyle style = workbook.createCellStyle();
            HSSFFont font = workbook.createFont();
            font.setBold(true);
            style.setFont(font);
            style.setDataFormat(HSSFDataFormat.getBuiltinFormat("m/d/yy h:mm"));
            //创建表头名称
            HSSFCell cell;
            for (int j =; j < str.length; j++) {
                cell = row.createCell(j);
                cell.setCellValue(str[j]);
                cell.setCellStyle(style);
            }
        } catch (Exception e) {
            log.info("导出时设置表头失败！");
            e.printStackTrace();
        }
    }
    private static void setData(HSSFSheet sheet, List<String[]> data) {
        try{
            int rowNum =;
            for (int i =; i < data.size(); i++) {
                HSSFRow row = sheet.createRow(rowNum);
                for (int j =; j < data.get(i).length; j++) {
                    row.createCell(j).setCellValue(data.get(i)[j]);
                }
                rowNum++;
            }
            log.info("表格赋值成功！");
        }catch (Exception e){
            log.info("表格赋值失败！");
            e.printStackTrace();
        }
    }
    private static void setBrowser(HttpServletResponse response, HSSFWorkbook workbook, String fileName) {
        try {
            //清空response
            response.reset();
            //设置response的Header
            response.addHeader("Content-Disposition", "attachment;filename=" + fileName);
            OutputStream os = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/vnd.ms-excel;charset=gb");
            //将excel写入到输出流中
            workbook.write(os);
            os.flush();
            os.close();
            log.info("设置浏览器下载成功！");
        } catch (Exception e) {
            log.info("设置浏览器下载失败！");
            e.printStackTrace();
        }
    }
    public static List<Object[]> importExcel(String fileName) {
        log.info("导入解析开始，fileName:{}",fileName);
        try {
            List<Object[]> list = new ArrayList<>();
            InputStream inputStream = new FileInputStream(fileName);
            Workbook workbook = WorkbookFactory.create(inputStream);
            Sheet sheet = workbook.getSheetAt();
            //获取sheet的行数
            int rows = sheet.getPhysicalNumberOfRows();
            for (int i =; i < rows; i++) {
                //过滤表头行
                if (i ==) {
                    continue;
                }
                //获取当前行的数据
                Row row = sheet.getRow(i);
                Object[] objects = new Object[row.getPhysicalNumberOfCells()];
                int index =;
                for (Cell cell : row) {
                    if (cell.getCellType().equals(NUMERIC)) {
                        objects[index] = (int) cell.getNumericCellValue();
                    }
                    if (cell.getCellType().equals(STRING)) {
                        objects[index] = cell.getStringCellValue();
                    }
                    if (cell.getCellType().equals(BOOLEAN)) {
                        objects[index] = cell.getBooleanCellValue();
                    }
                    if (cell.getCellType().equals(ERROR)) {
                        objects[index] = cell.getErrorCellValue();
                    }
                    index++;
                }
                list.add(objects);
            }
            log.info("导入文件解析成功！");
            return list;
        }catch (Exception e){
            log.info("导入文件解析失败！");
            e.printStackTrace();
        }
        return null;
    }
    //测试导入
    public static void main(String[] args) {
        try {
            String fileName = "G:/test.xlsx";
            List<Object[]> list = importExcel(fileName);
            for (int i =; i < list.size(); i++) {
                User user = new User();
                user.setName((String) list.get(i)[]);
                user.setAge((String) list.get(i)[]);
                user.setSex((String) list.get(i)[]);
                System.out.println(user.toString());
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

最后是controller层

package com.bdqn.springbootexcel.controller;
import com.bdqn.springbootexcel.pojo.User;
import com.bdqn.springbootexcel.service.ExcelService;
import lombok.extern.slfj.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import javax.servlet.http.HttpServletResponse;
import java.util.List;
@Slfj
@RestController
public class ExcelController {
    @Autowired
    private ExcelService excelService;
    @GetMapping("/export")
    public String exportExcel(HttpServletResponse response, String fileName, Integer pageNum, Integer pageSize) {
        fileName = "test.xlsx";
        if (fileName == null || "".equals(fileName)) {
            return "文件名不能为空！";
        } else {
            if (fileName.endsWith("xls") || fileName.endsWith("xlsx")) {
                Boolean isOk = excelService.exportExcel(response, fileName,, 10);
                if (isOk) {
                    return "导出成功！";
                } else {
                    return "导出失败！";
                }
            }
            return "文件格式有误！";
        }
    }
    @GetMapping("/import")
    public String importExcel(String fileName) {
        fileName = "G:/test.xlsx";
        if (fileName == null && "".equals(fileName)) {
            return "文件名不能为空！";
        } else {
            if (fileName.endsWith("xls") || fileName.endsWith("xlsx")) {
                Boolean isOk = excelService.importExcel(fileName);
                if (isOk) {
                    return "导入成功！";
                } else {
                    return "导入失败！";
                }
            }
            return "文件格式错误！";
        }
    }
    //饼状图的数据查询
    //@ResponseBody
    @RequestMapping("/pojos_bing")
    public List<User> gotoIndex() {
        List<User> pojos = excelService.find();
        return pojos;
    }
}

到现在为止我们的后端代码就已经完全搞定了，前端页面如下

写了一个简单前端用于测试

index.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<html lang="en">
<head>
    <meta charset="UTF-">
    <title>Title</title>
</head>
<body>
    <div align="center">
        <a th:href="@{'/export'}" rel="external nofollow" >导出</a>
        <a th:href="@{'/import'}" rel="external nofollow" >导入</a>
    </div>
</body>
</html>

当我们点击导出按钮时浏览器会自动下载

当我们点击导入按钮时会往数据库中添加表格数据

Java限流实现的几种方法详解
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在实际操作过程中如何避免出现SQL注入漏洞
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