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

 1 package com.beiwo.epet.entity;
 2 
 3 import java.io.Serializable;
 4 
 5 public class Master implements Serializable{
 6 
 7     private static final long serialVersionUID = -975099318646595542L;
 8 
 9     private int id;
10     private String loginId;
11     private String password;
12     public int getId() {
13         return id;
14     }
15     public void setId(int id) {
16         this.id = id;
17     }
18     public String getLoginId() {
19         return loginId;
20     }
21     public void setLoginId(String loginId) {
22         this.loginId = loginId;
23     }
24     public String getPassword() {
25         return password;
26     }
27     public void setPassword(String password) {
28         this.password = password;
29     }
30     public static long getSerialversionuid() {
31         return serialVersionUID;
32     }
33     
34     
35     
36 }

2.接口类的基类：

 1 package com.beiwo.epet.entity;
 2 
 3 import java.io.Serializable;
 4 
 5 public class Master implements Serializable{
 6 
 7     private static final long serialVersionUID = -975099318646595542L;
 8 
 9     private int id;
10     private String loginId;
11     private String password;
12     public int getId() {
13         return id;
14     }
15     public void setId(int id) {
16         this.id = id;
17     }
18     public String getLoginId() {
19         return loginId;
20     }
21     public void setLoginId(String loginId) {
22         this.loginId = loginId;
23     }
24     public String getPassword() {
25         return password;
26     }
27     public void setPassword(String password) {
28         this.password = password;
29     }
30     public static long getSerialversionuid() {
31         return serialVersionUID;
32     }
33     
34     
35     
36 }
37 
38 
39 
40 
41 
42 
43 
44 package com.beiwo.epet.dao;
45 
46 import com.beiwo.epet.entity.Master;
47 
48 public interface MasterDao extends BaseDao{
49     
50     /**
51      * 
52      * @param loginId 用户名
53      * @param password 密码
54      * @return Master  
55      */
56     public Master findMasterByLoginIdAndPassword(String loginId,String password);
57     
58 }

3.接口类的基类的实现类

 1 package com.beiwo.epet.dao;
 2 
 3 import com.beiwo.epet.entity.Master;
 4 
 5 public interface MasterDao extends BaseDao{
 6     
 7     /**
 8      * 
 9      * @param loginId 用户名
10      * @param password 密码
11      * @return Master  
12      */
13     public Master findMasterByLoginIdAndPassword(String loginId,String password);
14     
15 }
16 
17 
18 
19 
20 
21 package com.beiwo.epet.dao;
22 
23 import com.beiwo.epet.entity.Master;
24 
25 public interface MasterDao extends BaseDao{
26     
27     /**
28      * 
29      * @param loginId 用户名
30      * @param password 密码
31      * @return Master  
32      */
33     public Master findMasterByLoginIdAndPassword(String loginId,String password);
34     
35 }

4.创建业务逻辑层级的接口类PetService

 1 package com.beiwo.epet.service;
 2 
 3 import com.beiwo.epet.entity.Master;
 4 
 5 public interface MasterService {
 6     
 7     public Master login(String loginId,String password);
 8     
 9     
10 }

5.创建业务逻辑层的接口实现类

 1 package com.beiwo.epet.service.impl;
 2 
 3 import com.beiwo.epet.dao.MasterDao;
 4 import com.beiwo.epet.dao.impl.MasterDaoImpl;
 5 import com.beiwo.epet.entity.Master;
 6 import com.beiwo.epet.service.MasterService;
 7 
 8 public class MasterServiceImpl implements MasterService{
 9 
10     @Override
11     public Master login(String loginId, String password) {
12         MasterDao masterDao=new MasterDaoImpl();
13         return masterDao.findMasterByLoginIdAndPassword(loginId, password);
14     }
15 
16 }

6.测试类：

 1 package com.beiwo.epet.test;
 2 
 3 import java.util.Scanner;
 4 
 5 import org.junit.Test;
 6 
 7 import com.beiwo.epet.entity.Master;
 8 import com.beiwo.epet.service.MasterService;
 9 import com.beiwo.epet.service.impl.MasterServiceImpl;
10 
11 public class TestMasterDao {
12 
13     @Test
14     public void testLogin(){
15         MasterService masterService=new MasterServiceImpl();
16         
17         Scanner input=new Scanner(System.in);
18         
19         System.out.println("请输入用户名:");
20         String loginId=input.nextLine().trim();//去掉两端的空格
21         
22         System.out.println("请输入密码:");
23         String password=input.nextLine().trim();
24         
25         
26         Master master=masterService.login(loginId, password);
27         
28         if(null!=master){
29             System.out.println("登陆成功");
30         }else{
31             System.out.println("登陆失败");
32         }
33         
34         
35         
36     }
37     
38 
39 }