JDBC_完整版

1，新建WEB项目：JDBC

2，导入驱动

将mysql-connector-java-5.0.8-bin.jar包放入web-inf目录下面的lib目录中

3，新建User类，放入entity包中

package songyan.login.etity;

import java.util.Date;

public class User {
    private int id;
    private String name;
    private String password;
    private String email;
    private Date birthday;
    
    
    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 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;
    }
    
    
    
}

4，新建dbinfo.properties

选中src，右击new--File  

File Name :dbinfo.properties

点击左下角source，写入代码

driverClass=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/day06
user=root
password=247418

5.新建Util.java 放入Util包

抽取getConnection（）和closeAll（Connection conn，Statement sta，ResultSet rs）

package songyan.login.util;

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

public class Util {
    private static String driverClass;
    private static String url;
    private static String user;
    private static String password;
    
    static{
        ResourceBundle rb= ResourceBundle.getBundle("dbinfo");
        driverClass=rb.getString("driverClass");
        url=rb.getString("url");
        user=rb.getString("user");
        password=rb.getString("password");
        try {
            Class.forName(driverClass);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
    
    public static Connection getConnection() throws SQLException
    {
        return DriverManager.getConnection(url,user,password);
    }
    
    public static  void closeAll(Connection conn,Statement sta,ResultSet rs)
    {
        if(rs!=null)
        {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            rs=null;
        }
        
        if(sta!=null)
        {
            try {
                sta.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            sta=null;
        }
        
        if(conn!=null)
        {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            conn=null;
        }
    }
}

6，新建DoLogin.java

package songyan.servlet;

import java.io.IOException;
import java.io.PrintWriter;
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 javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import songyan.login.etity.User;
import songyan.login.util.Util;

public class Dologin {
public static User findUser(String name,String password) throws SQLException
{
    User u=null;
    Connection conn;
    PreparedStatement sta;
    ResultSet rs;
    String sql="select * from users where name=? and password=?";
    
    conn=Util.getConnection();
    sta=conn.prepareStatement(sql);
    sta.setString(1, name);
    sta.setString(2, password);
    rs=sta.executeQuery();
    
    while(rs.next())
    {
        u=new User();
        u.setId(rs.getInt(1));
        u.setName(rs.getString(2));
        u.setPassword(rs.getString(3));
        u.setEmail(rs.getString(4));
        u.setBirthday(rs.getDate(5));
    }
    
    return u;
}
}

7,新建Login.java

package songyan.servlet;

import java.sql.SQLException;
import java.util.Scanner;

import songyan.login.etity.User;

public class Login
{
    public static void main(String[] args) throws SQLException
    {
        System.out.println("请输入用户名：");
        Scanner in =new Scanner(System.in);
        String name=in.next();
        System.out.println("请输入密码");
        String pass=in.next();
        
        User u=Dologin.findUser(name,pass);
        if(u==null)
        {
            System.out.println("用户名或密码不正确");
        }
        else
        {
            System.out.println("欢迎你"+name);
        }
    }
}

 8.测试：