JDBC_面对对象的使用方式

最新推荐文章于 2025-06-13 15:30:03 发布

原创最新推荐文章于 2025-06-13 15:30:03 发布 · 339 阅读

0 ·

CC 4.0 BY-SA版权

本文介绍了一个使用Java进行数据库操作的示例项目，包括连接数据库、执行查询、更新记录等基本功能，并展示了如何通过PreparedStatement安全地执行SQL命令。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

<div>package dao;

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

public class Shujuku_luoji {
	private static final String username="root";
	private static final String password="0908";
	private static final String url="jdbc:mysql://localhost:3306/liu";
	private static final String com="com.mysql.jdbc.Driver";
	private static Connection conn=null;
	private static PreparedStatement pstmt=null;
	private static ResultSet rs=null;
	
	public static Connection getConn(){
		try {
			Class.forName(com);
			conn=DriverManager.getConnection(url, username, password);
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return conn;
	}
	
	public static ResultSet doQuery(String sql){
		try {
			pstmt=getConn().prepareStatement(sql);
			rs=pstmt.executeQuery();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return rs;
	}
	
	public static int doUpdate(String sql){
		int rs=0;
		try {
			pstmt=getConn().prepareStatement(sql);
			rs=pstmt.executeUpdate();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return rs;
	}
	
	public static void colse(){
		try {
			if(rs!=null){rs.close();}
			if(pstmt!=null){pstmt.close();}
			if(conn!=null){conn.close();}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

</div><div>

package dao;

import java.util.List;

import dto.Denglu_bean;
import dto.Student_bean;

public interface Jieko {
	public List Query();
	public Denglu_bean select(Denglu_bean gs);
	public boolean add(Denglu_bean gs);
	public boolean delete(int id);
	public boolean update(Student_bean gs);

}

</div><div>

package dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import dto.Denglu_bean;
import dto.Student_bean;

public class Jiekoshixian implements Jieko {

	@Override
	public List Query() {
		//查全表
		String sql="select * from student";
		List listtu=new ArrayList();
		Connection conn=Shujuku_luoji.getConn();
		try {
			PreparedStatement pstmt=conn.prepareStatement(sql);
			ResultSet rs=pstmt.executeQuery();
			while(rs.next()){
				int id=rs.getInt(1);
				String name=rs.getString(2);
				String birth=rs.getString(3);
				String sex=rs.getString(4);
				String edu=rs.getString(5);
				String province=rs.getString(6);
				String address=rs.getString(7);
				String tel=rs.getString(8);
				int classid=rs.getInt(9);
				String bak=rs.getString(10);
				Student_bean b=new Student_bean(id,name,birth,sex,edu,province,address,tel,classid,bak);
				listtu.add(b);
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			Shujuku_luoji.colse();
		}
		return listtu;
	}

	@Override
	public Denglu_bean select(Denglu_bean gs) {
		//查一条，登陆
		String sql="select * from mima where username=?";
		Denglu_bean b=null;
		try {
			Connection conn=Shujuku_luoji.getConn();
			PreparedStatement pstmt=conn.prepareStatement(sql);
			pstmt.setString(1, gs.getUsername());
			ResultSet rs=pstmt.executeQuery();
				
				if(rs.next()){
					String username=rs.getString(1);
					String password=rs.getString(2);
							b=new Denglu_bean(username,password);
				}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return b;
	}

	@Override
	public boolean add(Denglu_bean gs) {	
		//加一条，注册
		boolean flan=false;
		String sql="insert into mima values(?,?)";
		int aa;
		try {
			Connection conn=Shujuku_luoji.getConn();
			PreparedStatement pstmt=conn.prepareStatement(sql);
			pstmt.setString(1,gs.getUsername());
			pstmt.setString(2,gs.getPassword());
			aa = pstmt.executeUpdate();
				if(aa>0){
					flan=true;
				}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return flan;
	}

	@Override
	public boolean delete(int id) {
		//删一条
		boolean flan=false;
		String sql="delete from student where id=?";
		try {
			Connection conn=Shujuku_luoji.getConn();
			PreparedStatement pstmt=conn.prepareStatement(sql);
			pstmt.setInt(1,id);
			pstmt.executeQuery();
			flan=true;
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			Shujuku_luoji.colse();
		}
		return flan;
	}

	@Override
	public boolean update(Student_bean gs) {
		//改一条
		boolean flan=false;
		String sql="update student set password=? where id=?";
		try {
			Connection conn=Shujuku_luoji.getConn();
			PreparedStatement pstmt=conn.prepareStatement(sql);
			pstmt.setInt(1, gs.getId());
			pstmt.setString(2,gs.getName());
			pstmt.setString(3, gs.getBirth());
			pstmt.setString(4, gs.getSex());
			pstmt.setString(5, gs.getEdu());
			pstmt.setString(6, gs.getProvince());
			pstmt.setString(7, gs.getAddress());
			pstmt.setString(8, gs.getTel());
			pstmt.setInt(9, gs.getClassid());
			pstmt.setString(10, gs.getBak());
			int aa=pstmt.executeUpdate();
			if(aa>0){
				flan=true;
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return flan;
	}

}

</div>