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！");
}
}