MyBatis第一个项目示例

1、创建一个Java project，JikeBook

2、添加项目所需的依赖包

如 mybatis-3.2.8.jar,是实现mybatis功能所必需的依赖包

mysql-connector-java-3.0.17-ga-bin.jar是连接mysql数据库的依赖包，

log4j是日志输出依赖包

3、在src目录下创建各个package

4、首先创建log4j.properties

 1 log4j.rootLogger=DEBUG, Console
 2
 3 #Console
 4 log4j.appender.Console=org.apache.log4j.ConsoleAppender
 5 log4j.appender.Console.layout=org.apache.log4j.PatternLayout
 6 log4j.appender.Console.layout.ConversionPattern=%d [%t] %-5p [%c] - %m%n
 7
 8 log4j.logger.java.sql.ResultSet=INFO
 9 log4j.logger.org.apache=INFO
10 log4j.logger.java.sql.Connection=DEBUG
11 log4j.logger.java.sql.Statement=DEBUG
12 log4j.logger.java.sql.PreparedStatement=DEBUG

将一些日志的输出更改为DEBUG，才能输出相关日志信息

5、在jike.book.map包下创建jikeUser.xml

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2
 3
 4 <!DOCTYPE mapper
 5     PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
 6     "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 7
 8 <mapper namespace="/">
 9
10   <select id="findById"  parameterType="int"  resultType="jike.book.pojo.JiKeUser">
11         select * from jikeUser where id=#{id}
12   </select>
13
14
15 </mapper>

6、在jike.book.map包下创建MyBatisConfig.xml

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2
 3
 4 <!DOCTYPE configuration
 5     PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
 6     "http://mybatis.org/dtd/mybatis-3-config.dtd">
 7
 8 <configuration>
 9
10   <environments default="development">
11      <environment id="development">
12        <transactionManager type="JDBC">
13        </transactionManager>
14        <dataSource type="POOLED">
15              <property name="driver" value="com.mysql.jdbc.Driver"/>
16              <property name="url" value="jdbc:mysql://localhost:3306/jikebook"/>
17              <property name="username" value="root"/>
18              <property name="password" value=""/>
19        </dataSource>
20      </environment>
21   </environments>
22
23   <mappers>
24         <mapper resource="jike/book/map/jikeUser.xml"/>
25   </mappers>
26
27 </configuration>

7、在jike.book.pojo下创建JiKeUser.java

 1 package jike.book.pojo;
 2
 3 public class JiKeUser {
 4     private int id;
 5     private String userName;
 6     private String password;
 7     public int getId() {
 8         return id;
 9     }
10     public void setId(int id) {
11         this.id = id;
12     }
13     public String getUserName() {
14         return userName;
15     }
16     public void setUserName(String userName) {
17         this.userName = userName;
18     }
19     public String getPassword() {
20         return password;
21     }
22     public void setPassword(String password) {
23         this.password = password;
24     }
25 }

8、在jike.book.test下创建TestHello.java

 1 package jike.book.test;
 2
 3 import java.io.IOException;
 4 import java.io.Reader;
 5
 6 import jike.book.pojo.JiKeUser;
 7
 8 import org.apache.ibatis.io.Resources;
 9 import org.apache.ibatis.session.SqlSession;
10 import org.apache.ibatis.session.SqlSessionFactory;
11 import org.apache.ibatis.session.SqlSessionFactoryBuilder;
12
13 public class TestHello {
14
15     public static void main(String[] args) {
16
17         String resource = "jike/book/map/MyBatisConfig.xml";
18         Reader reader = null;
19         SqlSession session;
20         try {
21             reader = Resources.getResourceAsReader(resource);
22         } catch (IOException e) {
23             e.printStackTrace();
24         }
25         SqlSessionFactory sqlMapper = new SqlSessionFactoryBuilder()
26                 .build(reader);
27         session = sqlMapper.openSession();
28         JiKeUser temp = session.selectOne("findById", 1);
29         System.out.println(temp.getUserName());
30         session.close();
31     }
32
33 }

最后运行项目：

得到了数据库中的数据