大三下jsp作业六

User

package test21;

public class User {

    private String name;
    private String id;
    private String password;
    
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    
    public String toString() {
        return "User [name=" + name + ", id=" + id + ", password=" + password + "]";
    }
    
}

JDBCUtils

package test21;

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

public class JDBCUtils {
    private static Connection con;

    static {
        try {
            Class.forName("com.mysql.jdbc.Driver");

            String url = "jdbc:mysql://127.0.0.1:3306/mysqldb";
            String username = "root";
            String password = "admin";

            con = DriverManager.getConnection(url, username, password);
        } catch (Exception e) {

            e.printStackTrace();
        }

    }

    public static Connection getConnection() {
        return con;
    }

}

UsersDao

package test21;

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

public class UsersDao {

    public List FindAllUser() {
        Connection con = JDBCUtils.getConnection();
        PreparedStatement pst = null;
        ResultSet rs = null;
        try {
            pst = con.prepareStatement("select * from user ");
            rs = pst.executeQuery();
            List<User> list = new ArrayList<User>();
            while (rs.next()) {
                User u = new User();
                u.setName(rs.getString("name"));
                u.setPassword(rs.getString("password"));
                u.setId(rs.getString("id"));
                list.add(u);
            }
            rs.close();
            pst.close();
            con.close();
            return list;

        } catch (Exception e) {

            e.printStackTrace();
        }

        return null;
    }

    public List FindUserById() {
        Connection con = JDBCUtils.getConnection();
        PreparedStatement pst = null;
        ResultSet rs = null;
        try {
            pst = con.prepareStatement("select id from user ");
            rs = pst.executeQuery();
            List<User> list = new ArrayList<User>();
            while (rs.next()) {
                User u = new User();
                u.setId(rs.getString("id"));
                list.add(u);
            }
            rs.close();
            pst.close();
            con.close();
            return list;

        } catch (Exception e) {

            e.printStackTrace();
        }

        return null;

    }

    public void JdbcInsert() {
        Connection con = JDBCUtils.getConnection();
        PreparedStatement pst = null;
        try {
            pst = con.prepareStatement("insert into user (name,id,password) value (?,?,?) ");
            pst.setString(1, "xiaoyu");
            pst.setString(2, "0105");
            pst.setString(3, "999999");
            int row = pst.executeUpdate();
            pst.close();
            con.close();
            if (row == 1) {
                System.out.println("添加成功");
            } else {
                System.out.println("添加失败");
            }

        } catch (Exception e) {

            e.printStackTrace();
        }

    }

    public void UpdateUser() {
        Connection con = JDBCUtils.getConnection();
        PreparedStatement pst = null;
        try {
            pst = con.prepareStatement("update user set name=? where id='0105' ");
            pst.setString(1, "hahaha");
            int row = pst.executeUpdate();
            pst.close();
            con.close();
            if (row == 1) {
                System.out.println("修改成功");
            } else {
                System.out.println("修改失败");
            }

        } catch (Exception e) {

            e.printStackTrace();
        }

    }

    public void DeleteUser() {
        Connection con = JDBCUtils.getConnection();
        PreparedStatement pst = null;
        try {
            pst = con.prepareStatement("delete from user where name='hahaha'");
            int row = pst.executeUpdate();
            pst.close();
            con.close();
            if (row == 1) {
                System.out.println("删除成功");
            } else {
                System.out.println("删除失败");
            }

        } catch (Exception e) {

            e.printStackTrace();
        }

    }

}

FindAllUserTest

package test21;

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

public class FindAllUserTest {

    public static void main(String[] args) {

        UsersDao ud = new UsersDao();
        List<User> list = ud.FindAllUser();
        System.out.println(list.size());
        testlist(list);
    }

    public static void testlist(List list) {
        Iterator i = list.iterator();
        while (i.hasNext()) {
            System.out.println(i.next());
        }
    }
}

 

 

 FindUserByIdTest

package test21;

import java.util.Iterator;
import java.util.List;

public class FindUserByIdTest {

    public static void main(String[] args) {
        UsersDao ud = new UsersDao();

        List list = ud.FindUserById();
        System.out.println(list.size());
        testlist(list);
    }

    public static void testlist(List list) {
        Iterator i = list.iterator();
        while (i.hasNext()) {
            System.out.println(i.next());
        }

    }
}

 JdbcInsertTest

package test21;

public class JdbcInsertTest {

    public static void main(String[] args) {
        UsersDao ud=new UsersDao();
        ud.JdbcInsert();

    }

}

 

 UpdateUserTest

package test21;

public class UpdateUserTest {

    public static void main(String[] args) {
        UsersDao ud=new UsersDao();
        ud.UpdateUser();

    }

}

 

 DeleteUserTest

package test21;

public class DeleteUserTest {

    public static void main(String[] args) {
        UsersDao ud=new UsersDao();
        ud.DeleteUser();
    }

}