Java中使用Mybatis操作数据库主要有两种方法：注解和xml配置，注解相对比较简单和方便，两种方式的效果一致。本文以注解的方式说明用Mybatis访问数据库的方法
一、创建数据表(MySql)
|
1
2
3
4
5
6
7
8
9
|
-- ------------------------------ Table structure for admininfo-- ----------------------------DROP TABLE IF EXISTS `admininfo`;
CREATE TABLE `admininfo` (
`ID` int(11) NOT NULL AUTO_INCREMENT,
`AdminName` varchar(20) NOT NULL,
PRIMARY KEY (`ID`)
) ENGINE=InnoDB AUTO_INCREMENT=25 DEFAULT CHARSET=latin1;
|
二、创建mybatis的配置文件：mybatisConf.xml，由于使用maven进行管理，所以放在java-->resources文件夹下，其它位置也可以，只有最终在\target\classes\mybatisConf.xml生成文件即可
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
|
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"><configuration>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<!-- 配置数据库连接信息 -->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="username" value="root" />
<property name="password" value="root" />
</dataSource>
</environment>
</environments>
<mappers>
<!-- 注册映射接口，该接口文件包含了数据访问方法和SQL -->
<mapper class="dal.dataaccess.IAdminInfoMapper" />
</mappers>
</configuration>
|
三、创建IAdminInfoMapper文件（本文中包名为dal.dataaccess)
该接口的功能主要是提供对AdminInfo表的数据操作
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
|
package dal.dataaccess;
import java.util.List;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import dal.beans.AdminInfo;
import dal.beans.AdminRightInfo;
public interface IAdminInfoMapper {
//使用@Select注解指明getById方法要执行的SQL
@Select("select * from admininfo where id=#{id}")
public AdminInfo getById(int id);
//使用@Select注解指明getAll方法要执行的SQL
@Select("select * from admininfo")
public List<AdminInfo> getAll();
//使用@Insert注解指明add方法要执行的SQL
@Insert("insert into admininfo(adminName) values(#{adminName})")
public int add(AdminInfo user);
//使用@Update注解指明update方法要执行的SQL
@Update("update admininfo set adminName=#{adminName} where id=#{id}")
public int update(AdminInfo user);
//使用@Delete注解指明deleteById方法要执行的SQL
@Delete("delete from admininfo where id=#{id}")
public int deleteById(int id);
} |
四、定义操作数据库的公共方法
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
package framework.utils;
import java.io.InputStream;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
public class MyBatisUtil {
/**
* 获取SqlSessionFactory
*
* @return SqlSessionFactory
*/
public static SqlSessionFactory getSqlSessionFactory() {
String resource = "mybatisConf.xml";
InputStream is = MyBatisUtil.class.getClassLoader().getResourceAsStream(resource);
SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);
return factory;
}
/**
* 获取SqlSession
*
* @return SqlSession
*/
public static SqlSession getSqlSession() {
return getSqlSessionFactory().openSession();
}
/**
* 获取SqlSession
*
* @param isAutoCommit
* true 表示创建的SqlSession对象在执行完SQL之后会自动提交事务 false
* 表示创建的SqlSession对象在执行完SQL之后不会自动提交事务，这时就需要我们手动调用sqlSession.
* commit()提交事务
* @return SqlSession
*/
public static SqlSession getSqlSession(boolean isAutoCommit) {
return getSqlSessionFactory().openSession(isAutoCommit);
}
} |
五、对adminInfo表进行增删改查
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
|
package test;
import java.util.List;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import dal.beans.*;
import framework.utils.MyBatisUtil;
import dal.dataaccess.*;
public class MybatisAnnotationTest {
@Test
public void Select() {
SqlSession sqlSession = MyBatisUtil.getSqlSession();
// 得到AdminInfoMapper接口的实现类对象，IAdminInfoMapper接口的实现类对象由sqlSession.getMapper(IAdminInfoMapper.class)动态构建出来
IAdminInfoMapper mapper = sqlSession.getMapper(IAdminInfoMapper.class);
// 执行查询操作，将查询结果自动封装成User返回
AdminInfo bean = mapper.getById(13);
// 使用SqlSession执行完SQL之后需要关闭SqlSession
sqlSession.close();
System.out.println(bean.getId());
System.out.println(bean.getAdminName());
}
@Test
public void SelectAll() {
SqlSession sqlSession = MyBatisUtil.getSqlSession();
IAdminInfoMapper mapper = sqlSession.getMapper(IAdminInfoMapper.class);
List<AdminInfo> bean = mapper.getAll();
sqlSession.close();
System.out.println(bean.size());
}
@Test
public void Insert() {
SqlSession sqlSession = MyBatisUtil.getSqlSession();
IAdminInfoMapper mapper = sqlSession.getMapper(IAdminInfoMapper.class);
AdminInfo bean = new AdminInfo();
bean.setAdminName("Admin" + System.currentTimeMillis());
int result = mapper.add(bean);
sqlSession.commit();
sqlSession.close();
System.out.println(result);
}
@Test
public void Update() {
SqlSession sqlSession = MyBatisUtil.getSqlSession();
IAdminInfoMapper mapper = sqlSession.getMapper(IAdminInfoMapper.class);
AdminInfo bean = new AdminInfo();
bean.setId(12);
bean.setAdminName("Admin" + System.currentTimeMillis());
int result = mapper.update(bean);
sqlSession.commit();
sqlSession.close();
System.out.println(result);
}
@Test
public void Delete() {
SqlSession sqlSession = MyBatisUtil.getSqlSession();
IAdminInfoMapper mapper = sqlSession.getMapper(IAdminInfoMapper.class);
int result = mapper.deleteById(12);
sqlSession.commit();
sqlSession.close();
System.out.println(result);
}
} |
六、由于使用了maven进行依赖管理，pom.xml还需要添加
|
1
2
3
4
5
6
7
8
9
10
|
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.38</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.3.0</version>
</dependency>
|