JSP第六次作业

package dao;

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

import javabean.User;
import utils.JDBCUtils;

public class UsersDao {
    //增加数据
    public boolean insert(User user){
        Connection con=null;
        Statement state=null;
        try {
            con=JDBCUtils.getCon();
            state=con.createStatement();
            java.util.Date birthday=user.getBirthDay();
            String sqlBirthday=String.format("%tF", birthday);
            String sql="insert into user(id,username,password,email,birthday) "
                    + "values('"+user.getId()+"','"
                    +user.getUsername()+"','"
                    +user.getPassword()+"','"
                    +user.getEmail()+"','"
                    +sqlBirthday+"')";
            int row=state.executeUpdate(sql);
            if(row>0){
                return true;
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            JDBCUtils.realse(null,state,con);
        }
        return false;
    }
    
    
    
    //查询全部数据
    public List<User> findAllUser(){
        Connection con=null;
        Statement state=null;
        ResultSet rs=null;
        try {
            con=JDBCUtils.getCon();
            state=con.createStatement();
            String sql="select * from user";
            rs=state.executeQuery(sql);
            List<User> list=new ArrayList<User>();
            while(rs.next()){
                User user=new User();
                user.setId(rs.getInt("id"));
                user.setUsername(rs.getString("username"));
                user.setPassword(rs.getString("password"));
                user.setEmail(rs.getString("email"));
                java.sql.Date birthDay=rs.getDate("birthday");
                user.setBirthDay(birthDay);
                list.add(user);
            }
            return list;
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            JDBCUtils.realse(rs,state,con);
        }
        return null;
    }
    
    
    
    //根据ID查询记录
    public User findById(int id){
        Connection con=null;
        PreparedStatement prs=null;
        ResultSet rs=null;
        try {
            con=JDBCUtils.getCon();
            String sql="select * from user where id=?";
            prs=con.prepareStatement(sql);
            prs.setInt(1, id);
            rs=prs.executeQuery();
            if(rs.next()){
                User user=new User();
                user.setId(rs.getInt("id"));
                user.setUsername(rs.getString("username"));
                user.setPassword(rs.getString("password"));
                user.setEmail(rs.getString("email"));
                java.sql.Date birthDay=rs.getDate("birthday");
                user.setBirthDay(birthDay);
                return user;
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            JDBCUtils.realse(rs,prs,con);
        }
        return null;
    }
    
    
    //根据ID修改
    public boolean update(User user){
        Connection con=null;
        PreparedStatement prs=null;
        try {
            con=JDBCUtils.getCon();
            String sql="update user set username=?,password=? where id=?";
            prs=con.prepareStatement(sql);
            prs.setString(1, user.getUsername());
            prs.setString(2, user.getPassword());
            prs.setInt(3, user.getId());
            int row=prs.executeUpdate();
            if(row>0){
                return true;
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            JDBCUtils.realse(null,prs,con);
        }
        return false;
        
    }
    
    
    //删除根据Id
    public boolean deleteById(int id){
        Connection con=null;
        PreparedStatement prs=null;
        try {
            con=JDBCUtils.getCon();
            String sql="delete from user where id=?";
            prs=con.prepareStatement(sql);
            prs.setInt(1, id);
            int row=prs.executeUpdate();
            if(row>0){
                return true;
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            JDBCUtils.realse(null,prs,con);
        }
        return false;
        
    }
    

}
package javabean;

import java.util.Date;

public class User {
    private int id;
    private String username;
    private String password;
    private String 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 String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public Date getBirthDay() {
        return birthDay;
    }
    public void setBirthDay(Date birthDay) {
        this.birthDay = birthDay;
    }
}
package utils;

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

public class JDBCUtils {
    public static Connection getCon(){
        try {
            Class.forName("com.mysql.jdbc.Driver");
            Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/jdbc","root","root");
            return con;
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }
    //关闭连接
    public static void realse(ResultSet rs,Statement state,Connection con){
        try {
            if(rs !=null){
                rs.close();
            }
            if(state !=null){
                state.close();
            }
            if(con !=null){
                con.close();
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
    }

}
package Test;

import java.util.Date;

import dao.UsersDao;
import javabean.User;

public class InsTest {

    public static void main(String[] args) {
        UsersDao dao=new UsersDao();
        User user=new User();
        user.setId(1);
        user.setUsername("zhaoqian");
        user.setPassword("123456");
        user.setEmail("1558938514@qq.com");
        user.setBirthDay(new Date());
        System.out.println(dao.insert(user));
    }

}
package Test;

import java.util.ArrayList;
import java.util.List;

import dao.UsersDao;
import javabean.User;

public class ShowTest {

    public static void main(String[] args) {
        UsersDao dao=new UsersDao();
        List<User> list=dao.findAllUser();
        for(int i=0;i<list.size();i++){
            System.out.println(list.get(i));
        }

    }

}
package Test;

import dao.UsersDao;
import javabean.User;

public class ShowOneTest {

    public static void main(String[] args) {
        UsersDao dao=new UsersDao();
        User u=dao.findById(1);
        System.out.println(u.getUsername());
    }

}
package Test;

import dao.UsersDao;
import javabean.User;

public class UpdateTest {

    public static void main(String[] args) {
        UsersDao dao=new UsersDao();
        User user=new User();
        user.setId(1);
        user.setUsername("zhangsan");
        user.setPassword("zhangsan123");
        System.out.println(dao.update(user));
    }

}
package Test;

import dao.UsersDao;

public class DelectTest {

    public static void main(String[] args) {
        UsersDao dao=new UsersDao();
        System.out.println(dao.deleteById(1));
    }

}

原文地址:https://www.cnblogs.com/zq542960954/p/12746145.html