Java實現Excel批量導入數據庫

springboot實現Excel批量導入數據庫

前言：項目開發中最容易碰到的需求即將Excel數據批量上傳到數據庫中存儲 -> Java實現，Excel數據表，MySQL數據庫，具體步驟如下…

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1.新建excel表，填寫測試數據

2.新建項目工程，修改pom依賴以及application.properties如下

pom.xml

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.1</version>
</dependency>
<!--java對象狀態自動映射到關係數據庫中數據上-->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-orm</artifactId>
    <version>5.0.2.RELEASE</version>
</dependency>
<!--實現類與xml之間的相互轉換-->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-oxm</artifactId>
    <version>5.0.2.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-core</artifactId>
    <version>5.2.12.Final</version>
</dependency>
<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-jpamodelgen</artifactId>
    <version>5.2.12.Final</version>
</dependency>
<dependency>
    <groupId>org.springframework.data</groupId>
    <artifactId>spring-data-jpa</artifactId>
    <version>2.2.3.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--前端頁面我這裏使用了thymeleaf模板引擎-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.12</version>
</dependency>
<!--使用POI讀取文件-->
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>3.17</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.17</version>
</dependency>

application.properties

spring.datasource.username=123456
spring.datasource.password=123456
spring.datasource.url=jdbc:mysql://localhost:3306/excel?useUnicode=true&useSSL=false&characterEncoding=UTF-8&serverTimezone=UTC
#配置通過jpa自動創建表
spring.jpa.hibernate.ddl-auto=create
#打印SQL
spring.jpa.show-sql=true

3.創建實體類，進行關係映射

啓動項目就會自動創建實體類中的表，創建完之後會發現數據庫裏的字段和實體類裏的字段順序是不一樣，是亂序狀態，是因爲hibernate源碼中用的是TreeMap存儲實體類字段，TreeMap屬性是無序的；所以解決辦法如下：

• 找到源碼文件
  
• 在本項目中創建一個和源碼類一樣的包結構和一樣名字的類，複製源碼文件所有代碼到新建的類中
  
• 將上圖標識的TreeMap 修改爲LinkedHashMap修改好之後啓動項目，會發現程序走的是新創建的類

package com.wxy.excel.entity;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
import java.io.Serializable;

@Entity
@Table(name = "excel")
public class Excel implements Serializable {
    //serialVersionUID適用於java序列化機制
    private static final long serialVersionUID = 1L;
    @Id
    @Column(length=36)
    private String id;
    @Column(length=45,nullable=false,unique=true)
    private String username;
    @Column(length=100,nullable=false,unique=true)
    private String email;
    @Column(length=45,nullable=false)
    private String password;
    @Column(length=45)
    private String role;

   //省略getter and setter 以及 constructor

4.Excel的DAO類接口，與Excel有關的持久化操作方法

package com.wxy.excel.mapper;
import com.wxy.excel.entity.Excel;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface ExcelRepository extends JpaRepository<Excel,String> {
}

5.創建service層接口

Excel的Service類接口，與Excel有關的業務邏輯方法

package com.wxy.excel.service;

import org.springframework.web.multipart.MultipartFile;

public interface ExcelService {

    boolean getExcel(MultipartFile file) throws Exception;
}

6.service層方法實現

Excel的Service類，與用戶信息有關的業務邏輯方法

package com.wxy.excel.service;
import com.wxy.excel.mapper.ExcelRepository;
import com.wxy.excel.entity.Excel;
import org.apache.poi.ss.usermodel.*;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;
import java.util.ArrayList;
import java.util.List;

@Service
public class ExcelServiceImpl implements ExcelService{
    @Autowired
    private ExcelRepository excelRepository;
    @Override
    public boolean getExcel(MultipartFile file) throws Exception {
        List<Excel> list = new ArrayList<Excel>();
        //1.得到上傳的表
        Workbook workbook2 = WorkbookFactory.create(file.getInputStream());
        //2.獲取test工作表 注意test就是excel下面的sheet名稱
        Sheet sheet2 = workbook2.getSheet("test");
        //3.獲取表的總行數
        int num = sheet2.getLastRowNum();
        //4.獲取表總列數
        int col = sheet2.getRow(0).getLastCellNum();
        //5.遍歷excel每一行
        for (int j = 0; j <= num; j++) {
            Row row1 = sheet2.getRow(j);
            // 如果單元格中有數字或者其他格式的數據，則調用setCellType()轉換爲string類型
            Cell cell1 = row1.getCell(0);
            cell1.setCellType(CellType.STRING);
            //獲取表中第i行，第2列的單元格
            Cell cell2 = row1.getCell(1);
            cell2.setCellType(CellType.STRING);
            //獲取excel表的第i行，第3列的單元格
            Cell cell3 = row1.getCell(2);
            cell3.setCellType(CellType.STRING);
            Cell cell4 = row1.getCell(3);
            cell4.setCellType(CellType.STRING);
            Cell cell5 = row1.getCell(4);
            cell5.setCellType(CellType.STRING);
            //這裏new 一個對象，用來裝填從頁面上傳的Excel數據，字段根據上傳的excel決定
            Excel excel= new Excel();
            excel.setId(cell1.getStringCellValue());
            excel.setUsername(cell2.getStringCellValue());
            excel.setEmail(cell3.getStringCellValue());
            excel.setPassword(cell4.getStringCellValue());
            excel.setRole(cell5.getStringCellValue());
            list.add(excel);
            System.out.println("excel"+excel);
        }
        excelRepository.saveAll(list);
        return true;
    }
}

7.Controller層實現

package com.wxy.excel.controller;
import com.wxy.excel.service.ExcelService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.multipart.MultipartFile;

@Controller
public class ExcelController {

    @Autowired
    private ExcelService excelService;

    @GetMapping("/upload")
    public String goUpload(){
        return "upload";
    }
    @PostMapping("/excel")
    public String upload(MultipartFile file, Model model) throws Exception {
        boolean flag = excelService.getExcel(file);
        if(flag){
            model.addAttribute("Message", "上傳成功");
        }else{
            model.addAttribute("Message", "上傳失敗");
        }
        return "upload";
    }
}

8.前端html實現

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>批量上傳</title>
</head>
<body>
    <form enctype="multipart/form-data" method="post" action="/excel">
        <input type="file" name="file" /> <input type="submit" value="上傳" />
    </form>
</body>
</html>

9.項目結構圖，以及實現文件上傳效果如下

10.項目demo已經上傳到github，下載地址

https://github.com/Wangxy9527/ExcelToDatabase

或者直接clone即可：

[email protected]/ExcelToDatabase.git

https://github.com/Wangxy9527/ExcelToDatabase.git

結語：本文主要實現功能爲將Excel數據導入到數據庫中，不懂不理解或者對以上文章有疑問的小夥伴歡迎留言…