Mybatis------1.HelloWord

 

1.新建java工程

2.导入jar包

3.建立数据库以及建表

 

4.在工程中加入mybatis-conf.xml配置

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
 3 <configuration>
 4     <environments default="development">
 5         <environment id="development">
 6             <transactionManager type="JDBC" />
 7             <dataSource type="POOLED">
 8                 <property name="driver" value="com.mysql.jdbc.Driver" />
 9                 <property name="url"
10                     value="jdbc:mysql://localhost:3306/blog" />
11                 <property name="username" value="root" />
12                 <property name="password" value="root" />
13             </dataSource>
14         </environment>
15     </environments>
16 </configuration>

5.编写实体类Users

 1 package com.entor.po;
 2 
 3 import java.util.Date;
 4 
 5 public class Users {
 6     private int id;
 7     private String username;
 8     private String password;
 9     private Date createTime;
10     
11     public int getId() {
12         return id;
13     }
14     public void setId(int id) {
15         this.id = id;
16     }
17     public String getUsername() {
18         return username;
19     }
20     public void setUsername(String username) {
21         this.username = username;
22     }
23     public String getPassword() {
24         return password;
25     }
26     public void setPassword(String password) {
27         this.password = password;
28     }
29     public Date getCreateTime() {
30         return createTime;
31     }
32     public void setCreateTime(Date createTime) {
33         this.createTime = createTime;
34     }
35     
36 
37 }

6.编写映射文件UserMapper.xml

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 3 <mapper namespace="usermapper">
 4 
 5     <!-- parameterType表示参数类型
 6     resultType表示结果类型 -->
 7     <select id="getUser" parameterType="int" resultType="com.entor.po.Users">
 8         <!-- 注意这里是真正的sql，#{}作为参数的占位符 -->
 9         select * from user where id = #{id}
10     </select>
11 
12 </mapper>

7.在主配置中加入mapper

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
 3 <configuration>
 4     <environments default="development">
 5         <environment id="development">
 6             <transactionManager type="JDBC" />
 7             <dataSource type="POOLED">
 8                 <property name="driver" value="com.mysql.jdbc.Driver" />
 9                 <property name="url"
10                     value="jdbc:mysql://localhost:3306/blog" />
11                 <property name="username" value="root" />
12                 <property name="password" value="root" />
13             </dataSource>
14         </environment>
15     </environments>
16 
17     <mappers>
18         <mapper resource="com/entor/po/UserMapper.xml" />
19     </mappers>
20 </configuration>

8.编写测试类

 1 package com.entor.test;
 2 
 3 
 4 
 5 import org.apache.ibatis.io.Resources;
 6 import org.apache.ibatis.session.SqlSession;
 7 import org.apache.ibatis.session.SqlSessionFactory;
 8 import org.apache.ibatis.session.SqlSessionFactoryBuilder;
 9 
10 import com.entor.po.Users;
11 
12 public class Test {
13 
14     public static void main(String[] args) throws Exception{
15         
16         //创建SqlSessionFactory
17         SqlSessionFactory factory = new SqlSessionFactoryBuilder()
18                     .build(Resources.getResourceAsStream("mybatis-conf.xml"));
19         
20         
21         SqlSession session = factory.openSession();
22         
23         String statment = "usermapper.getUser";  //等于mapper的namespace+具体sql的id
24         
25         Users user = session.selectOne(statment, 1);
26         
27         System.out.println(user.getUsername());
28         
29     }
30 }

 

 

整体结构：

 

posted @ 2018-08-07 15:28  温润如玉公子花  阅读(72)  评论(0)    收藏  举报