用java将Excel表格导入导出数据库

创建实体类

实体类里的属性和数据库表的列保持一致

package grgbanking.entity;

public class StuEntity {

private int id;
private String name;
private String sex;
private int num;

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

@Override
public String toString() {
return "StuEntity [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;
}

}

创建连接数据库的工具类

这里采用mysql的连接，注意要标明编码格式，防止出现乱码

package grgbanking;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DbUtil {
String driver = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/study?characterEncoding=utf8";
Connection conn = null;
ResultSet res = null;
public void DataBase(){
try{
Class.forName(driver);
conn = DriverManager.getConnection(url, "root", "HUI1212");

}catch(ClassNotFoundException e){
System.out.println("驱动加载失败");
e.printStackTrace();
}catch(SQLException e){
System.out.println("无法连接数据库");
e.printStackTrace();
}
}
/*
* 查询
*/
public ResultSet Search(String sql, String str[]){
DataBase();
try{
PreparedStatement pst = conn.prepareStatement(sql);
if(str != null){
for(int i = 1; i < str.length; i++ ){
pst.setString(i+1, str[i]);
}
}
res = pst.executeQuery();
}catch(Exception e){
e.printStackTrace();
}
return res;
}
/*
* 增删查
*/
public int State(String sql, String str[]){
int a = 0;
DataBase();
try {
PreparedStatement pst = conn.prepareStatement(sql);
if (str != null) {
for (int i = 0; i < str.length; i++) {
pst.setString(i + 1, str[i]);
}
}
a = pst.executeUpdate();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return a;
}
}

创建一个service类

用于查询数据库和本地的电子表格里面的数据

package grgbanking.services;

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

import grgbanking.DbUtil;
import grgbanking.entity.StuEntity;
import jxl.Sheet;
import jxl.Workbook;

/**
*
* @author cjyun
* @category 读取Excel表中所有的数据、操作数据（查询、更新）
*/
public class StuService {
public static List<StuEntity> list = new ArrayList<StuEntity>();

/**
* 查询表中平数据
*/
public static List<StuEntity> getAllDb(){

try {
DbUtil db = new DbUtil();
String sql = "select * from stu";
ResultSet res = db.Search(sql, null);
while (res.next()){
int id = res.getInt("id");
String name = res.getString("name");
String sex = res.getString("sex");
int num = res.getInt("num");
list.add(new StuEntity(id,name,sex,num));
}
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
return list;
}
/**
* 查询电子表中的数据
*/
public static List<StuEntity> getAllByExcel(String file){

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+" rows:"+rows);
for (int i = 1; i < rows; i++) {
for (int j = 0; j < clos; j++) {
//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();
list.add(new StuEntity(Integer.parseInt(id), name, sex, Integer.parseInt(num)));
}
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return list;}
/**
* id是否存在
*/
public static boolean isExist(int id){
try {
DbUtil db = new DbUtil();
String sql = "select * from stu where id ="+id;
System.out.println(sql);
ResultSet res = db.Search(sql, new String[]{id+""});
if(res.next()){
return true;
}
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
return false;
}
public static void main(String[] args) {
/*List<StuEntity> all = getAllDb();
for(StuEntity stu:all){
System.out.println(stu.toString());
}*/
System.out.println(isExist(5));
}
}

创建控制层

从数据库导入Excel

## 新建SQLToExcel类 ##

package grgbanking.controller;

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

import grgbanking.entity.StuEntity;
import grgbanking.services.StuService;
import jxl.Workbook;
import jxl.write.Label;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;

public class SQLToExcel {
public static void main(String[] args) {
try {
WritableWorkbook wwb = null;
String fileName = "D://book.xls";
File file = new File(fileName);
if(!file.exists()){
file.createNewFile();
}
wwb = Workbook.createWorkbook(file);
WritableSheet ws = wwb.createSheet("Test Shee 1", 0);
List<StuEntity> list = StuService.getAllDb();
Label labelId = new Label(0,0,"编号{id}");
Label labelName = new Label(1,0,"编号{name}");
Label labelSex = new Label(2,0,"编号{sex}");
Label labelNum = new Label(3,0,"编号{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(0,i+1,list.get(i).getName());
Label labelSex_i= new Label(0,i+1,list.get(i).getSex());
Label labelNum_i= new Label(0,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
wwb.close();
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}
}

从Excel导入数据库

## 新建ExcelToSQL类 ##

package grgbanking.controller;

import java.util.List;

import grgbanking.DbUtil;
import grgbanking.entity.StuEntity;
import grgbanking.services.StuService;

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

DbUtil db=new DbUtil();

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

总结

不管是从Excel导入到数据库中，还是从数据库中导入到Excel。首先都要获取到表格的列和行的数据，然后再同过java的一些方法将之写入。不同的是，Excel中必须按照顺序进行写入和输出。