Mapper动态代理方式

Mapper动态代理需要遵循以下规范：

  1. 接口的全路径和映射文件中mapper标签namespace保持一致
  2. 接口的方法名和映射文件的statementId保持一致
  3. 接口方法的参数类型和映射文件的parameterType保持一致，返回类型和映射文件的resultType保持一致
  4. 接口名称和映射文件的名称保持一致
  5. 接口和映射文件放在一起

sqlMapconfig.xml配置文件 1 <?xml version="1.0" encoding="UTF-8"?> 2 <!DOCTYPE configuration

 3         PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
 4         "http://mybatis.org/dtd/mybatis-3-config.dtd">
 5 <configuration>
 6  <environments default="development">
 7         <environment id="development">
 8             <!-- 使用jdbc事务管理-->
 9             <transactionManager type="JDBC" />
10             <!-- 数据库连接池-->
11             <dataSource type="POOLED">
12                 <property name="driver" value="数据库驱动" />
13                 <property name="url" value="链接地址" />
14                 <property name="username" value="用户名" />
15                 <property name="password" value="密码" />
16             </dataSource>
17      </environment>
18     </environments>
19     <mappers>
20 <!--        此种方法要求mapper接口名称和mapper映射文件名称相同，且放在同一个目录中。-->
21         <mapper class="mapper.mapperDao"></mapper>
22 <!--        注册指定包下的所有mapper接口
23             此种方法要求mapper接口名称和mapper映射文件名称相同，且放在同一个目录中
24 -->
25         <package name="包全路径名"/>
26     </mappers>
27 </configuration>

 

mapper.xml映射文件

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE mapper
 3         PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
 4         "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 5 <!--namespace和接口全路径名保持一致-->
 6 <mapper namespace="mapper.mapperDao">
 7     <select id="findAll" parameterType="int" resultType="commodity.commodity">
 8         select * from commodity where id=#{id}
 9     </select>
10 </mapper>

pojo类：

 1 public class commodity {
 2     private int id;
 3     private String name;
 4     private int price;
 5 
 6     @Override
 7     public String toString() {
 8         return "commodity{" +
 9                 "id=" + id +
10                 ", name='" + name + '\'' +
11                 ", price=" + price +
12                 '}';
13     }
14 
15     public int getId() {
16         return id;
17     }
18 
19     public void setId(int id) {
20         this.id = id;
21     }
22 
23     public String getName() {
24         return name;
25     }
26 
27     public void setName(String name) {
28         this.name = name;
29     }
30 
31     public int getPrice() {
32         return price;
33     }
34 
35     public void setPrice(int price) {
36         this.price = price;
37     }
38 }

 

接口：

1 import commodity.commodity;
2 
3 public interface mapperDao {
4     public commodity findAll(int id);
5     public  void insert();
6 }

 

测试：

 1  public void Test() throws IOException {
 2         SqlSessionFactoryBuilder sqlSessionFactoryBuilder=new SqlSessionFactoryBuilder();
 3         SqlSessionFactory sqlSessionFactory=sqlSessionFactoryBuilder.build(Resources.getResourceAsStream("sqlMapconfig.xml"));
 4         //通过sqlSession获取sqlSession对象
 5         SqlSession sqlSession=sqlSessionFactory.openSession();
 6         //获取代理对象
 7         mapperDao mapperDao=sqlSession.getMapper(mapper.mapperDao.class);
 8         commodity commodity= mapperDao.findAll(1);
 9         System.out.println(commodity);
10     }

 

 

 

 

 

 

posted @ 2020-04-14 14:30  荣耀马  阅读(208)  评论(0)  编辑  收藏  举报