自学资料总结
实现的功能：
- Java实现Excel导入数据库，如果存在就更新
- 数据库中的数据导入到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：javenforexcel
4、表名:stu
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
package com.javen.db;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;public class DBhepler { /*String driver = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; String url = "jdbc:sqlserver://127.0.0.1;DatabaseName=javenforexcel";*/ String driver = "com.mysql.jdbc.Driver"; String url = "jdbc:mysql://127.0.0.1:3306/javenforexcel"; Connection con = null; ResultSet res = null; public void DataBase() { try { Class.forName(driver); con = DriverManager.getConnection(url, "root", "root"); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block System.err.println("装载 JDBC/ODBC 驱动程序失败。" ); e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block System.err.println("无法连接数据库" ); e.printStackTrace(); } } // 查询 public ResultSet Search(String sql, String str[]) { DataBase(); try { PreparedStatement pst =con.prepareStatement(sql); if (str != null) { for (int i = 0; i < str.length; i++) { pst.setString(i + 1, str[i]); } } res = pst.executeQuery(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } return res; } // 增删修改 public int AddU(String sql, String str[]) { int a = 0; DataBase(); try { PreparedStatement pst = con.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; }}
表的实体如下
package com.javen.entity;/** * @author Javen * @Email zyw205@gmail.com * */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; } } Java实现Excel导入数据核心类 读取Excel表中所有的数据、操作数据（查询、更新）
package com.javen.service;import java.io.File;import java.sql.ResultSet;import java.sql.SQLException;import java.util.ArrayList;import java.util.List;import jxl.Sheet;import jxl.Workbook;import com.javen.db.DBhepler;import com.javen.entity.StuEntity;/** * @author Javen * @Email zyw205@gmail.com * */public class StuService { /** * 查询stu表中所有的数据 * @return */ public static List getAllByDb(){ List list=new ArrayList (); try { DBhepler db=new DBhepler(); String sql="select * from stu"; ResultSet rs= db.Search(sql, null); while (rs.next()) { int id=rs.getInt("id"); String name=rs.getString("name"); String sex=rs.getString("sex"); int num=rs.getInt("num"); //System.out.println(id+" "+name+" "+sex+ " "+num); list.add(new StuEntity(id, name, sex, num)); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return list; } /** * 查询指定目录中电子表格中所有的数据 * @param file 文件完整路径 * @return */ public static List getAllByExcel(String file){ List list=new ArrayList (); 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(); System.out.println("id:"+id+" name:"+name+" sex:"+sex+" num:"+num); list.add(new StuEntity(Integer.parseInt(id), name, sex, Integer.parseInt(num))); } } } catch (Exception 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 { DBhepler db=new DBhepler(); ResultSet rs=db.Search("select * from stu 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 all=getAllByDb(); for (StuEntity stuEntity : all) { System.out.println(stuEntity.toString()); }*/ System.out.println(isExist(1)); } } 数据的数据导入到Excel表
package com.javen.excel;import java.io.File;import java.util.List;import com.javen.entity.StuEntity;import com.javen.service.StuService;import jxl.Workbook;import jxl.write.Label;import jxl.write.WritableSheet;import jxl.write.WritableWorkbook;public class TestDbToExcel { 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 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 wwb.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } }} Excel表中的数据导入到MySql数据库
package com.javen.excel;import java.util.List;import com.javen.db.DBhepler;import com.javen.entity.StuEntity;import com.javen.service.StuService;/** * @author Javen * @Email zyw205@gmail.com * */public class TestExcelToDb { public static void main(String[] args) { //得到表格中所有的数据 List listExcel=StuService.getAllByExcel("d://book.xls"); /*//得到数据库表中所有的数据 List listDb=StuService.getAllByDb();*/ DBhepler db=new DBhepler(); for (StuEntity stuEntity : listExcel) { int id=stuEntity.getId(); if (!StuService.isExist(id)) { //不存在就添加 String sql="insert into stu (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 stu set name=?,sex=?,num=? where id=?"; String[] str=new String[]{stuEntity.getName(),stuEntity.getSex(),stuEntity.getNum()+"",id+""}; db.AddU(sql, str); } } }}
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