创建DAO模式的步骤

1.建立数据库epet 2.创建实体类，和相对应的数据库是对应的 3.创建Dao的基类接口类BaseDao 4.创建Dao的实现类BaseDaoImpl 5.创建具体表的Dao类

6.创建具体表的Dao实现类 7.创建业务逻辑层级的接口类PetService 8.创建业务逻辑层的接口实现类：PetServiceImpl  9.创建测试类

 下面写一个登录的操作用DAO模式：

1.创建实体类：人的实体类

package com.beiwo.epet.entity;

import java.io.Serializable;

public class Master implements Serializable{

    private static final long serialVersionUID = -975099318646595542L;

    private int id;
    private String loginId;
    private String password;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getLoginId() {
        return loginId;
    }
    public void setLoginId(String loginId) {
        this.loginId = loginId;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public static long getSerialversionuid() {
        return serialVersionUID;
    }
    
    
    
}

2.接口类的基类：

package com.beiwo.epet.entity;

import java.io.Serializable;

public class Master implements Serializable{

    private static final long serialVersionUID = -975099318646595542L;

    private int id;
    private String loginId;
    private String password;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getLoginId() {
        return loginId;
    }
    public void setLoginId(String loginId) {
        this.loginId = loginId;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public static long getSerialversionuid() {
        return serialVersionUID;
    }
    
    
    
}







package com.beiwo.epet.dao;

import com.beiwo.epet.entity.Master;

public interface MasterDao extends BaseDao{
    
    /**
     * 
     * @param loginId 用户名
     * @param password 密码
     * @return Master  
     */
    public Master findMasterByLoginIdAndPassword(String loginId,String password);
    
}

3.接口类的基类的实现类

package com.beiwo.epet.dao;

import com.beiwo.epet.entity.Master;

public interface MasterDao extends BaseDao{
    
    /**
     * 
     * @param loginId 用户名
     * @param password 密码
     * @return Master  
     */
    public Master findMasterByLoginIdAndPassword(String loginId,String password);
    
}





package com.beiwo.epet.dao;

import com.beiwo.epet.entity.Master;

public interface MasterDao extends BaseDao{
    
    /**
     * 
     * @param loginId 用户名
     * @param password 密码
     * @return Master  
     */
    public Master findMasterByLoginIdAndPassword(String loginId,String password);
    
}

4.创建业务逻辑层级的接口类PetService

package com.beiwo.epet.service;

import com.beiwo.epet.entity.Master;

public interface MasterService {
    
    public Master login(String loginId,String password);
    
    
}

 5.创建业务逻辑层的接口实现类

package com.beiwo.epet.service.impl;

import com.beiwo.epet.dao.MasterDao;
import com.beiwo.epet.dao.impl.MasterDaoImpl;
import com.beiwo.epet.entity.Master;
import com.beiwo.epet.service.MasterService;

public class MasterServiceImpl implements MasterService{

    @Override
    public Master login(String loginId, String password) {
        MasterDao masterDao=new MasterDaoImpl();
        return masterDao.findMasterByLoginIdAndPassword(loginId, password);
    }

}

6.测试类：

package com.beiwo.epet.test;

import java.util.Scanner;

import org.junit.Test;

import com.beiwo.epet.entity.Master;
import com.beiwo.epet.service.MasterService;
import com.beiwo.epet.service.impl.MasterServiceImpl;

public class TestMasterDao {

    @Test
    public void testLogin(){
        MasterService masterService=new MasterServiceImpl();
        
        Scanner input=new Scanner(System.in);
        
        System.out.println("请输入用户名:");
        String loginId=input.nextLine().trim();//去掉两端的空格
        
        System.out.println("请输入密码:");
        String password=input.nextLine().trim();
        
        
        Master master=masterService.login(loginId, password);
        
        if(null!=master){
            System.out.println("登陆成功");
        }else{
            System.out.println("登陆失败");
        }
        
        
        
    }
    

}