JAVA读取数据库数据保存到Excel中

1.jar包选择

2.数据库表

3.JDBC连接数据库工具类

package Test;

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

public class DBhepler {
	String url ="jdbc:mysql://192.168.0.109:3306/javenforexcel?useUnicode=true&characterEncoding=utf-8";

	String user="root";
	String pwd="123456";
	Connection conn=null;
	ResultSet rs=null;
	
	public void DataBase() {
		try {
			Class.forName("com.mysql.jdbc.Driver");
			conn=DriverManager.getConnection(url, user, pwd);
		} catch (ClassNotFoundException e) {
			System.out.println("装载JDBC 驱动程序失败");
			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 = 0; i < str.length; i++) {
					pst.setString(i+1, str[i]);
				}
				
			}
			
			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;
		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: handle exception
		}
		
		return a;
		
		
	}
	
}

4.查询数据库数据表的工具类

package service;

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

import Test.DBhepler;
import entity.StuEntity;

public class StuService {
	//查询表中所有的数据
	public static List<StuEntity> getAllByDb(){
		List<StuEntity>list=new ArrayList<StuEntity>();
		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");
				StuEntity entity=new StuEntity();
				entity.setId(id);
				entity.setName(name);
				entity.setSex(sex);
				entity.setNum(num);
			list.add(entity);
			}
		} catch (Exception e) {
			// TODO: handle exception
		}
		return list;
	}
	
	

}

5.建立Excel表，并将读取到的数据库表的数据写入到表格中

package excel;

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

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

public class TestDbToExcel {
	
	public static void main(String[] args) {
		try {
			WritableWorkbook wwb=null;
			//创建可写入的Excel工作薄
			
			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<StuEntity> 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）");
			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();
			System.out.println("数据写入成功");
			//关闭Excel工作簿对象
			
			wwb.close();
			
		} catch (Exception e) {
			
			System.out.println("数据写入失败");
			e.printStackTrace();
		}
	}

}