Java实现将Excel导入数据库和从数据库中导出为Excel

实现的功能：

• 用Java实现从Excel导入数据库，如果存在就更新
• 将数据库中的数据导出为Excel

1、添加jxl.jar mysql-connector-java.1.7-bin.jar包到项目的lib目录下­

2、Excel文件目录:D://book.xls

3、数据库名：Stu

4、表名:student

5、编写类：连接mysql的字符串方法、插入的方法、实体类­­

表结构如下 ：

连接数据库的工具类

DBhelper.java

package com.cn.gao;
import java.sql.*;
public class DBhelper {
    Connection conn = null;
    ResultSet rs = null;
    //连接数据库
    public void connect(){
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/Stu","root","1234");
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
//            e.printStackTrace();
            System.out.println("数据库驱动加载失败！");
        } catch (SQLException e) {
            // TODO Auto-generated catch block
//            e.printStackTrace();
            System.out.println("数据库连接失败！");
        }

    }

    //查询
    public ResultSet Search(String sql, String str[]){
        connect();
        try {
            PreparedStatement pst = conn.prepareStatement(sql);
            if(str != null){
                for(int i=0;i<str.length-1;i++){
                    pst.setString(i+1, str[i]);
                }
                pst.setInt(str.length, Integer.parseInt(str[str.length-1]));
            }
            rs = pst.executeQuery();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return rs;
    }

    //增删修改
    public int AddU(String sql, String str[]){
        int a =0;
        connect();
        try {
            PreparedStatement pst = conn.prepareStatement(sql);
            if(str != null){
                for(int i=0;i<str.length-1;i++){
                    pst.setString(i+1, str[i]);
                }
                pst.setInt(str.length, Integer.parseInt(str[str.length-1]));
            }
            a = pst.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return a;
    }

}

表的实体如下

Stu.java

package com.cn.gao;
//学生实体类
public class Stu {
    private int id;
    private String name;
    private String sex;
    private int num;

    public Stu(){

    }

    public Stu(int id,String name,String sex,int num){
        this.id = id;
        this.name = name;
        this.sex = sex;
        this.num = num;
    }

    public String toString(){
        return "Stu[id="+id+", name="+name+", sex="+sex+", num="+num+"]";
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }
}

Java实现将Excel导入数据库的核心类 读取Excel表中所有的数据、操作数据（查询、更新）

StuService.java

package com.cn.gao;

import java.io.File;
import java.io.IOException;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import jxl.Sheet;
import jxl.Workbook;
import jxl.read.biff.BiffException;

//实现Excel导入数据库核心类，读取Excel表中所有的数据，操作数据（查询、更新）
public class StuService {
    /**
     * 查询数据库中Student表中所有的数据
     */
    public static List<Stu> getAllByDb(){
        List<Stu> list = new ArrayList<Stu>();
        DBhelper db = new DBhelper();
        String sql = "select * from student";
        ResultSet rs = db.Search(sql, null);
        try {
            while(rs.next()){
                int id = rs.getInt("id");
                String name = rs.getString("name");
                String sex = rs.getString("sex");
                int num = rs.getInt("num");
                list.add(new Stu(id,name,sex,num));
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return list;
    }
    /**
     * 查询指定目录中Excel表格中所有数据
     * @param file为文件完整路径
     * @return
     */
    public static List<Stu> getAllByExcel(String file){
        List<Stu> list = new ArrayList<Stu>();
            try {
                Workbook rwb = Workbook.getWorkbook(new File(file));
                Sheet rs = rwb.getSheet("Test Shee 1"); //或者rwb.getSheet(0)
                int clos=rs.getColumns();//得到所有的列
                int rows=rs.getRows();//得到所有的行
                System.out.println("clos:"+clos+" rows:"+rows);
                for(int i=1;i<rows;i++){
                    int j=0;
                    //第一个是列数，第二个是行数
                    String id=rs.getCell(j++, i).getContents();//默认最左边编号也算一列 所以这里得j++
                    String name=rs.getCell(j++, i).getContents();
                    String sex=rs.getCell(j++, i).getContents();
                    String num=rs.getCell(j++, i).getContents();

                    System.out.println("id:"+id+" name:"+name+" sex:"+sex+" num:"+num);
                    list.add(new Stu(Integer.parseInt(id), name, sex, Integer.parseInt(num)));
                }
            } catch (BiffException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return list;
    }

    /**
     * 通过id判断是否存在
     * @param id
     * @return
     */
    public static boolean isExist(int id){
        try {
            DBhelper db=new DBhelper();
            ResultSet rs=db.Search("select * from student where id=?", new String[]{id+""});
            if (rs.next()) {
                return true;
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return false;
    }

    public static void main(String[] args) {
        /*List<Stu> all=getAllByDb();
        for (Stu stuEntity : all) {
            System.out.println(stuEntity.toString());
        }*/

        System.out.println(isExist(1));

    }
}

将数据库中的数据导出到Excel表

FromDbToExcel.java

package com.cn.gao;

import java.io.File;
import java.util.List;

import jxl.Workbook;
import jxl.write.Label;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;

public class FromDbToExcel {
    public static void main(String[] args) {
        try {
            WritableWorkbook wwb = null;

               // 创建可写入的Excel工作簿
               String fileName = "D://book.xls";
               File file=new File(fileName);
               if (!file.exists()) {
                   file.createNewFile();
               }
               //以fileName为文件名来创建一个Workbook
               wwb = Workbook.createWorkbook(file);

               // 创建工作表
               WritableSheet ws = wwb.createSheet("Test Shee 1", 0);

               //查询数据库中所有的数据
               List<Stu> list= StuService.getAllByDb();
               //要插入到的Excel表格的行号，默认从0开始
               Label labelId= new Label(0, 0, "编号(id)");//表示第
               Label labelName= new Label(1, 0, "姓名(name)");
               Label labelSex= new Label(2, 0, "性别(sex)");
               Label labelNum= new Label(3, 0, "薪水(num)");

               ws.addCell(labelId);
               ws.addCell(labelName);
               ws.addCell(labelSex);
               ws.addCell(labelNum);
               for (int i = 0; i < list.size(); i++) {

                   Label labelId_i= new Label(0, i+1, list.get(i).getId()+"");
                   Label labelName_i= new Label(1, i+1, list.get(i).getName());
                   Label labelSex_i= new Label(2, i+1, list.get(i).getSex());
                   Label labelNum_i= new Label(3, i+1, list.get(i).getNum()+"");
                   ws.addCell(labelId_i);
                   ws.addCell(labelName_i);
                   ws.addCell(labelSex_i);
                   ws.addCell(labelNum_i);
               }

              //写进文档
               wwb.write();
              // 关闭Excel工作簿对象
               System.out.println("数据导出成功!");
               wwb.close();

        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

将Excel表中的数据导入到MySql数据库

FromExcelToDb.java

package com.cn.gao;

import java.util.List;

public class FromExcelToDb {
    public static void main(String[] args) {
        //得到表格中所有的数据
        List<Stu> listExcel=StuService.getAllByExcel("d://book.xls");
        /*//得到数据库表中所有的数据
        List<Stu> listDb=StuService.getAllByDb();*/

        DBhelper db=new DBhelper();

        for (Stu stuEntity : listExcel) {
            int id=stuEntity.getId();
            if (!StuService.isExist(id)) {
                //不存在就添加
                String sql="insert into student (name,sex,num) values(?,?,?)";
                String[] str=new String[]{stuEntity.getName(),stuEntity.getSex(),stuEntity.getNum()+""};
                db.AddU(sql, str);
            }else {
                //存在就更新
                String sql="update student set name=?,sex=?,num=? where id=?";
                String[] str=new String[]{stuEntity.getName(),stuEntity.getSex(),stuEntity.getNum()+"",id+""};
                db.AddU(sql, str);
            }
        }
        System.out.println("数据更新成功！");
    }
}