• jsp第六次作业


    package com.sykdl.jdbc;
    
    import java.sql.Connection;
    import java.sql.PreparedStatement;
    import java.sql.ResultSet;
    import java.sql.Statement;
    import java.util.ArrayList;
    
    //进行数据的增删改查
    public class UserDao {
    	//1  提供添加方法
    	public boolean insert(User user) {
    		Connection con = null;
    		Statement stmt = null;
    		try {
    			//1创建连接对象
    			con = JDBCUtils.getCon();
    			//2 获取执行SQL语句的对象
    			stmt = con.createStatement();
    			//3执行sql语句
    			java.util.Date birthday = user.getBirthDay();
    			String sqlBirthDay = String.format("%tF", birthday);
    			String sql = "insert into user(id,name,password,email,birthday)"+"values('"
    			           +user.getId()+"','"
    			           +user.getUsername()+"','"
    			           +user.getPassword()+"','"
    			           +user.getEmail()+"','"
    			           +sqlBirthDay+"'"
    			           +")";
    			System.out.println(sql);
    			int row = stmt.executeUpdate(sql);
    			if(row>0) {
    				return true;
    			}
    		}catch(Exception e){
    			e.printStackTrace();
    			}finally {
    			JDBCUtils.release(null, stmt, con);
    		}
    		return false;
    	}
    	// 2 提供全部查找方式
    	public ArrayList<User> findAllUser(){
    		Connection con = null;
    		Statement stmt = null;
    		ResultSet rs = null;
    		try {
    			//1创建连接对象
    			con = JDBCUtils.getCon();
    			//2 获取执行SQL语句的对象
    			stmt = con.createStatement();
    			//3执行sql语句
    			String sql = "select * from user";
    			rs = stmt.executeQuery(sql);
    			//遍历 rs
    			ArrayList<User> list = new ArrayList<User>();
    			while(rs.next()) {
    				//一行数据对应一个对象 获取每一行数据,就设置一个user对象
    				User user = new User();
    				user.setId(rs.getInt("id"));
    				user.setUsername(rs.getString("name"));
    				user.setPassword(rs.getString("password"));
    				user.setEmail(rs.getString("email"));
    				java.sql.Date birthDay = rs.getDate("birthDay");
    				user.setBirthDay(birthDay);
    				//把对象添加到集合中
    				list.add(user);
    			}
    			return list;
    		}catch(Exception e) {
    			throw new RuntimeException(e);
    		}finally {
    			JDBCUtils.release(rs, stmt, con);
    			}
    		
    	}
    	//3根据ID来查找user
    	public User findUseiId(int id) {
    		Connection con = null;
    		PreparedStatement stmt = null;
    		ResultSet rs = null;
    		try {
    			//1创建连接对象
    			con = JDBCUtils.getCon();
    			//2 获取执行SQL语句的对象
    			String sql = "select * from user where id =?";
    			stmt = con.prepareStatement(sql);
    			//3执行sql语句
    			stmt.setInt(1,id);
    			System.out.println(sql);
    			rs = stmt.executeQuery();
    			//遍历 rs
    			if(rs.next()) {
    				//一行数据对应一个对象 获取每一行数据,就设置一个user对象
    				User user = new User();
    				user.setId(rs.getInt("id"));
    				user.setUsername(rs.getString("name"));
    				user.setPassword(rs.getString("password"));
    				user.setEmail(rs.getString("email"));
    				java.sql.Date birthDay = rs.getDate("birthDay");
    				user.setBirthDay(birthDay);
    			}
    			
    		}catch(Exception e) {
    			throw new RuntimeException(e);
    		}finally {
    			JDBCUtils.release(rs, stmt, con);
    			}
    		return null;
    	}
    	// 4 根据id来修改 User
    	public boolean updateUserId(User user) {
    
    		Connection con = null;
    		PreparedStatement stmt = null;
    		try {
    			//1创建连接对象
    			con = JDBCUtils.getCon();
    			//2 获取执行SQL语句的对象
    			String sql = "update user set name=?,password=? where id =?";
    			stmt = con.prepareStatement(sql);
    			stmt.setString(1,user.getUsername());
    			stmt.setString(2,user.getPassword());
    			stmt.setInt(3,user.getId());
    			//3执行sql语句
    			int row = stmt.executeUpdate();
    			if(row>0) {
    				return true;
    			}
    		}catch(Exception e) {
    			throw new RuntimeException(e);
    		}finally {
    			JDBCUtils.release(null, stmt, con);
    			}
    		return false;
    	
    	}
    	//根据id来删除User
    	public boolean delectUser(int id) {
    
    		Connection con = null;
    		PreparedStatement stmt = null;
    		try {
    			//1创建连接对象
    			con = JDBCUtils.getCon();
    			//2 获取执行SQL语句的对象
    			String sql = "delete from user where id =?";
    			stmt = con.prepareStatement(sql);
    			stmt.setInt(1,id);
    			//3执行sql语句
    			int row = stmt.executeUpdate();
    			if(row>0) {
    				return true;
    			}
    		}catch(Exception e) {
    			throw new RuntimeException(e);
    		}finally {
    			JDBCUtils.release(null, stmt, con);
    			}
    		return false;
    	
    	}
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    	
    }
    

      

    package com.sykdl.jdbc;
    
    import java.util.Date;
    
    public class User {
    	private int id;
    	private String username;
    	private String password;
    	private String email;
    	private Date birthday;
    	@Override
    	public String toString() {
    		return "User [id=" + id + ", username=" + username + ", password=" + password + ", email=" + email
    				+ ", birthday=" + birthday + ", birthDay=" + birthDay + "]";
    	}
    	public String getEmail() {
    		return email;
    	}
    	public void setEmail(String email) {
    		this.email = email;
    	}
    	private Date birthDay;
    	public int getId() {
    		return id;
    	}
    	public void setId(int id) {
    		this.id = id;
    	}
    	public String getUsername() {
    		return username;
    	}
    	public void setUsername(String username) {
    		this.username = username;
    	}
    	public String getPassword() {
    		return password;
    	}
    	public void setPassword(String password) {
    		this.password = password;
    	}
    	public Date getBirthDay() {
    		return birthDay;
    	}
    	public void setBirthDay(Date birthDay) {
    		this.birthDay = birthDay;
    	}
    }
    

      

    package com.sykdl.jdbc;
    
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.sql.Statement;
    
    public class JDBCUtils {
    	//获取连接的方法	
    	public static Connection getCon() throws Exception {
    		//1注册和加载驱动
    		Class.forName("com.mysql.cj.jdbc.Driver");
    		//2.获取连接
    		Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/keshe?useUnicode=true&characterEncoding=UTF8&useSSL=false&serverTimezone=Asia/Shanghai", "root", "root");
    		return con;
    	}
    	//关闭资源 释放资源
    	public static void release(ResultSet rs,Statement stmt,Connection con) {
    		if(rs!=null) {
    			try {
    				rs.close();
    			} catch (SQLException e) {
    				// TODO Auto-generated catch block
    				e.printStackTrace();
    			}
    			rs = null;
    		}
    		if(stmt!=null) {
    			try {
    				stmt.close();
    			} catch (SQLException e) {
    				// TODO Auto-generated catch block
    				e.printStackTrace();
    			}
    			stmt = null;
    		}
    		if(con!=null) {
    			try {
    				con.close();
    			} catch (SQLException e) {
    				// TODO Auto-generated catch block
    				e.printStackTrace();
    			}
    			con = null;
    		}
    	}
    }
    

      

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  • 原文地址:https://www.cnblogs.com/zqxxx/p/12751390.html
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