JSP&Servlet练习（购物小系统代码2）

dao

package dao;
import domain.Commodity;
import domain.Kind;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
public class CommodityDao {
    private String className="com.mysql.jdbc.Driver";
    private String url="jdbc:mysql://localhost:3306/shopping";
    private String password="cy414ljh212,,,";
    public Commodity selectCommodityByCid(int cid){
        Commodity commodity=null;
        try{
            Class.forName(className);
            Connection connection= DriverManager.getConnection(url,"root",password);
            String sql="SELECT KID,CID,CNAME,CBALANCE FROM COMMODITY WHERE CID = ?";
            PreparedStatement preparedStatement= connection.prepareStatement(sql);
            preparedStatement.setInt(1,cid);
            ResultSet resultSet=preparedStatement.executeQuery();
            if(resultSet.next()){
                Kind kind=new Kind();
                kind.setKid(resultSet.getInt("kid"));
                commodity=new Commodity(kind, resultSet.getInt("cid"), resultSet.getString("cname"),resultSet.getFloat("cbalance"));
            }
            resultSet.close();
            preparedStatement.close();
        }catch (Exception e){
            e.printStackTrace();
        }
        return commodity;
    }
    public ArrayList<Commodity> selectCommodity(int kid){
        ArrayList<Commodity> commodityArrayList=new ArrayList<Commodity>();
        try{
            Class.forName(className);
            Connection connection= DriverManager.getConnection(url,"root",password);
            String sql="SELECT KID,CID,CNAME,CBALANCE FROM COMMODITY WHERE KID = ?";
            PreparedStatement preparedStatement= connection.prepareStatement(sql);
            preparedStatement.setInt(1,kid);
            ResultSet resultSet=preparedStatement.executeQuery();
            while(resultSet.next()){
                Kind kind=new Kind();
                kind.setKid(resultSet.getInt("kid"));
                Commodity commodity=new Commodity(kind, resultSet.getInt("cid"), resultSet.getString("cname"),resultSet.getFloat("cbalance"));
                commodityArrayList.add(commodity);
            }
            resultSet.close();
            preparedStatement.close();
        }catch (Exception e){
            e.printStackTrace();
        }
        return commodityArrayList;
    }
}

package dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;

import domain.Kind;

public class DisplayDao {
    private String className="com.mysql.jdbc.Driver";
    private String url="jdbc:mysql://localhost:3306/shopping";
    private String password="cy414ljh212,,,";

    public ArrayList<Kind> selectAll(){
        ArrayList<Kind> kindArrayList=new ArrayList<Kind>();
        try{
            Class.forName(className);
            Connection connection= DriverManager.getConnection(url,"root",password);
            String sql="SELECT KID,KNAME FROM KIND";
            PreparedStatement preparedStatement= connection.prepareStatement(sql);
            ResultSet resultSet=preparedStatement.executeQuery();
            while(resultSet.next()){
                Kind kind=new Kind(resultSet.getInt("kid"),resultSet.getString("kname"));
                kindArrayList.add(kind);
            }
            resultSet.close();
            preparedStatement.close();
        }catch (Exception e){
            e.printStackTrace();
        }
        return kindArrayList;
    }
}

package dao;

import domain.Customer;

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

public class UserDao {
    private String className="com.mysql.jdbc.Driver";
    private String url="jdbc:mysql://localhost:3306/shopping";
    private String password="cy414ljh212,,,";

    private  final String SQL_USER="SELECT USERNAME,PASSWORD  FROM CUSTOMER WHERE USERNAME = ?";
    public Customer selectOne(String username){
        Customer customer=null;
        try{
            Class.forName(className);
            Connection connection= DriverManager.getConnection(url,"root",password);
            PreparedStatement preparedStatement= connection.prepareStatement(SQL_USER);
            preparedStatement.setString(1,username);
            ResultSet resultSet=preparedStatement.executeQuery();
            if(resultSet.next()){
                customer=new Customer();
                customer.setUsername(resultSet.getString("username"));
                customer.setPassword(resultSet.getString("password"));
                return  customer;
            }
            resultSet.close();
            preparedStatement.close();
        }catch (Exception e){
            e.printStackTrace();
        }
        return customer;
    }

}

domain

package domain;

public class Commodity {
    private Kind kind;
    private Integer cid;
    private String cname;
    private Float cbalance;

    public Commodity() {}

    public Commodity(Kind kind, Integer cid, String cname, Float cbalance) {
        this.kind = kind;
        this.cid = cid;
        this.cname = cname;
        this.cbalance = cbalance;
    }

    public Kind getKind() {
        return kind;
    }

    public Integer getCid() {
        return cid;
    }

    public String getCname() {
        return cname;
    }

    public Float getCbalance() {
        return cbalance;
    }

    public void setKind(Kind kind) {
        this.kind = kind;
    }

    public void setCid(Integer cid) {
        this.cid = cid;
    }

    public void setCname(String cname) {
        this.cname = cname;
    }

    public void setCbalance(Float cbalance) {
        this.cbalance = cbalance;
    }
}

package domain;

public class Customer {
    private String username;
    private String password;

    public Customer() {}

    public Customer(String username, String password) {
        this.username = username;
        this.password = password;
    }

    public String getUsername() {
        return username;
    }

    public String getPassword() {
        return password;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

package domain;

public class Kind {
    private Integer kid;
    private String kname;

    public Kind() {}

    public Kind(int kid, String kname) {
        this.kid = kid;
        this.kname = kname;
    }

    public int getKid() {
        return kid;
    }

    public String getKname() {
        return kname;
    }

    public void setKid(int kid) {
        this.kid = kid;
    }

    public void setKname(String kname) {
        this.kname = kname;
    }
}